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Sun Java System Application Server Standard and Enterprise Edition 7 2004Q2 Developer's Guide to NSAPI

> ## Chapter 6
> NSAPI Function Reference

> This chapter lists all the public C functions and macros of NSAPI in alphabetic order. These are the functions you use when writing your own Server Application Functions (SAFs).

> See Chapter 2, “Predefined SAFs and the Request Handling Process,” for a list of the pre-defined SAFs.

> Each function provides the name, syntax, parameters, return value, a description of what the function does, and sometimes an example of its use and a list of related functions.

> For more information on data structures, see Appendix A, "Data Structure Reference," and also look in the nsapi.h header file in the include directory in the build for Sun Java System Application Server 7.

> ##

> NSAPI Functions (in Alphabetical Order)

> For an alphabetical list of function names, see Appendix G, "Alphabetical List of NSAPI Functions and Macros."

> | C | D | F | L | M | N | P | R | S | U | V

> ##

> C

> ### CALLOC

> The CALLOC macro is a platform-independent substitute for the C library routine calloc. It allocates num*size bytes from the request’s memory pool. If pooled memory has been disabled in the configuration file (with the pool-init built-in SAF), PERM_CALLOC and CALLOC both obtain their memory from the system heap.

> ##### Syntax

> void *CALLOC(int num, int size)

> ##### Returns

> A void pointer to a block of memory.

> ##### Parameters

> int num is the number of elements to allocate.

> int size is the size in bytes of each element.

> ##### Example

> /* Allocate space for an array of 100 char pointers */
> char *name;
> name = (char *) CALLOC(100, sizeof(char *));

> ##### See also

> FREE, REALLOC, STRDUP, PERM_MALLOC, PERM_FREE, PERM_REALLOC, PERM_STRDUP

> ### cinfo_find

> The cinfo_find() function uses the MIME types information to find the type, encoding, and/or language based on the extension(s) of the Universal Resource Identifier (URI) or local file name. Use this information to send headers (rq->srvhdrs) to the client indicating the content-type, content-encoding, and content-language of the data it will be receiving from the server.

> The name used is everything after the last slash (/) or the whole string if no slash is found. File name extensions are not case-sensitive. The name may contain multiple extensions separated by period (.) to indicate type, encoding, or language. For example, the URI a/b/filename.jp.txt.zip could represent a Japanese language, text/plain type, zip encoded file.

> ##### Syntax

> cinfo *cinfo_find(char *uri);

> ##### Returns

> A pointer to a newly allocated cinfo structure if content info was found or NULL if no content was found

> The cinfo structure that is allocated and returned contains pointers to the content-type, content-encoding, and content-language, if found. Each is a pointer into static data in the types database, or NULL if not found. Do not free these pointers. You should free the cinfo structure when you are done using it.

> ##### Parameters

> char *uri is a Universal Resource Identifier (URI) or local file name. Multiple file name extensions should be separated by periods (.).

> ### condvar_init

> The condvar_init function is a critical-section function that initializes and returns a new condition variable associated with a specified critical-section variable. You can use the condition variable to prevent interference between two threads of execution.

> ##### Syntax

> CONDVAR condvar_init(CRITICAL id);

> ##### Returns

> A newly allocated condition variable (CONDVAR).

> ##### Parameters

> CRITICAL id is a critical-section variable.

> ##### See also

> condvar_notify, condvar_terminate, condvar_wait, crit_init, crit_enter, crit_exit, crit_terminate.

> ### condvar_notify

> The condvar_notify function is a critical-section function that awakens any threads that are blocked on the given critical-section variable. Use this function to awaken threads of execution of a given critical section. First, use crit_enter to gain ownership of the critical section. Then use the returned critical-section variable to call condvar_notify to awaken the threads. Finally, when condvar_notify returns, call crit_exit to surrender ownership of the critical section.

> ##### Syntax

> void condvar_notify(CONDVAR cv);

> ##### Returns

> void

> ##### Parameters

> CONDVAR cv is a condition variable.

> ##### See also

> condvar_init, condvar_terminate, condvar_wait, crit_init, crit_enter, crit_exit, crit_terminate.

> ### condvar_terminate

> The condvar_terminate function is a critical-section function that frees a condition variable. Use this function to free a previously allocated condition variable.

> ##### Warning

> Terminating a condition variable that is in use can lead to unpredictable results.

> ##### Syntax

> void condvar_terminate(CONDVAR cv);

> ##### Returns

> void

> ##### Parameters

> CONDVAR cv is a condition variable.

> ##### See also

> condvar_init, condvar_notify, condvar_wait, crit_init, crit_enter, crit_exit, crit_terminate.

> ### condvar_wait

> Critical-section function that blocks on a given condition variable. Use this function to wait for a critical section (specified by a condition variable argument) to become available. The calling thread is blocked until another thread calls condvar_notify with the same condition variable argument. The caller must have entered the critical section associated with this condition variable before calling condvar_wait.

> ##### Syntax

> void condvar_wait(CONDVAR cv);

> ##### Returns

> void

> ##### Parameters

> CONDVAR cv is a condition variable.

> ##### See also

> condvar_init, condvar_notify, condvar_terminate, crit_init, crit_enter, crit_exit, crit_terminate.

> ### crit_enter

> Critical-section function that attempts to enter a critical section. Use this function to gain ownership of a critical section. If another thread already owns the section, the calling thread is blocked until the first thread surrenders ownership by calling crit_exit.

> ##### Syntax

> void crit_enter(CRITICAL crvar);

> ##### Returns

> void

> ##### Parameters

> CRITICAL crvar is a critical-section variable.

> ##### See also

> crit_init, crit_exit, crit_terminate.

> ### crit_exit

> Critical-section function that surrenders ownership of a critical section. Use this function to surrender ownership of a critical section. If another thread is blocked waiting for the section, the block will be removed and the waiting thread will be given ownership of the section.

> ##### Syntax

> void crit_exit(CRITICAL crvar);

> ##### Returns

> void

> ##### Parameters

> CRITICAL crvar is a critical-section variable.

> ##### See also

> crit_init, crit_enter, crit_terminate.

> ### crit_init

> Critical-section function that creates and returns a new critical-section variable (a variable of type CRITICAL). Use this function to obtain a new instance of a variable of type CRITICAL (a critical-section variable) to be used in managing the prevention of interference between two threads of execution. At the time of its creation, no thread owns the critical section.

> ##### Warning

> Threads must not own or be waiting for the critical section when crit_terminate is called.

> ##### Syntax

> CRITICAL crit_init(void);

> ##### Returns

> A newly allocated critical-section variable (CRITICAL)

> ##### Parameters

> none.

> ##### See also

> crit_enter, crit_exit, crit_terminate.

> ### crit_terminate

> Critical-section function that removes a previously-allocated critical-section variable (a variable of type CRITICAL). Use this function to release a critical-section variable previously obtained by a call to crit_init.

> ##### Syntax

> void crit_terminate(CRITICAL crvar);

> ##### Returns

> void

> ##### Parameters

> CRITICAL crvar is a critical-section variable.

> ##### See also

> crit_init, crit_enter, crit_exit.

> ##

> D

> ### daemon_atrestart

> The daemon_atrestart function lets you register a callback function named by fn to be used when the server terminates. Use this function when you need a callback function to deallocate resources allocated by an initialization function. The daemon_atrestart function is a generalization of the magnus_atrestart function.

> The init.conf directives TerminateTimeout and ChildRestartCallback also affect the callback of NSAPI functions.

> ##### Syntax

> void daemon_atrestart(void (*fn)(void *), void *data);

> ##### Returns

> void

> ##### Parameters

> void (* fn) (void *) is the callback function.

> void *data is the parameter passed to the callback function when the server is restarted.

> ##### Example

> /* Register the log_close function, passing it NULL */
> /* to close *a log file when the server is */
> /* restarted or shutdown. */
> daemon_atrestart(log_close, NULL);
> NSAPI_PUBLIC void log_close(void *parameter)
> {
> system_fclose(global_logfd);
> }

> ##

> F

> ### fc_open

> The fc_open function returns a pointer to PRFileDesc that refers to an open file (fileName). The fileName must be the full pathname of an existing file. The file is opened in Read Mode only. The application calling this function should not modify the currency of the file pointed by the PRFileDesc * unless the DUP_FILE_DESC is also passed to this function. In other words, the application (at minimum) should not issue a read operation based on this pointer that would modify the currency for the PRFileDesc *. If such a read operation is required (that may change the currency for the PRFileDesc *), then the application should call this function with the argument DUP_FILE_DESC.

> On a successful call to this function a valid pointer to PRFileDesc is returned and the handle 'FcHdl' is properly initialized. The size information for the file is stored in the 'fileSize' member of the handle.

> ##### Syntax

> PRFileDesc *fc_open(const char *fileName, FcHdl *hDl,PRUint32 flags, Session *sn, Request *rq);

> ##### Returns

> Pointer to PRFileDesc, NULL on failure

> ##### Parameters

> const char *fileName is the full path name of the file to be opened

> FcHdl*hDl is a valid pointer to a structure of type FcHdl

> PRUint32 flags can be 0 or DUP_FILE_DESC

> Session *sn is a pointer to the session

> Request *rq is a pointer to the request

> ### fc_close

> The fc_close function closes a file opened using fc_open. This function should only be called with files opened using fc_open.

> ##### Syntax

> void fc_close(PRFileDesc *fd, FcHdl *hDl;

> ##### Returns

> void

> ##### Parameters

> PRFileDesc *fd A valid pointer returned from a prior call to fc_open

> FcHdl *hDl is a valid pointer to a structure of type FcHdl this pointer must have been initialized by a prior call to fc_open.

> ### filebuf_buf2sd

> The filebuf_buf2sd function sends a file buffer to a socket (descriptor) and returns the number of bytes sent.

> Use this function to send the contents of an entire file to the client.

> ##### Syntax

> int filebuf_buf2sd(filebuf *buf, SYS_NETFD sd);

> ##### Returns

> The number of bytes sent to the socket, if successful, or the constant IO_ERROR if the file buffer could not be sent

> ##### Parameters

> filebuf *buf is the file buffer which must already have been opened.

> SYS_NETFD sd is the platform-independent socket descriptor. Normally this will be obtained from the csd (client socket descriptor) field of the sn (Session) structure.

> ##### Example

> if (filebuf_buf2sd(buf, sn->csd) == IO_ERROR)
> return(REQ_EXIT);

> ##### See also

> filebuf_close, filebuf_open, filebuf_open_nostat, filebuf_getc.

> ### filebuf_close

> The filebuf_close function deallocates a file buffer and closes its associated file.

> Generally, use filebuf_open first to open a file buffer, and then filebuf_getc to access the information in the file. After you have finished using the file buffer, use filebuf_close to close it.

> ##### Syntax

> void filebuf_close(filebuf *buf);

> ##### Returns

> void

> ##### Parameters

> filebuf *buf is the file buffer previously opened with filebuf_open.

> ##### Example

> filebuf_close(buf);

> ##### See also

> filebuf_open, filebuf_open_nostat, filebuf_buf2sd, filebuf_getc

> ### filebuf_getc

> The filebuf_getc function retrieves a character from the current file position and returns it as an integer. It then increments the current file position.

> Use filebuf_getc to sequentially read characters from a buffered file.

> ##### Syntax

> filebuf_getc(filebuf b);

> ##### Returns

> An integer containing the character retrieved, or the constant IO_EOF or IO_ERROR upon an end of file or error.

> ##### Parameters

> filebuf b is the name of the file buffer.

> ##### See also

> filebuf_close, filebuf_buf2sd, filebuf_open, filebuf_open_nostat

> ### filebuf_open

> The filebuf_open function opens a new file buffer for a previously opened file. It returns a new buffer structure. Buffered files provide more efficient file access by guaranteeing the use of buffered file I/O in environments where it is not supported by the operating system.

> ##### Syntax

> filebuf *filebuf_open(SYS_FILE fd, int sz);

> ##### Returns

> A pointer to a new buffer structure to hold the data, if successful or NULL if no buffer could be opened.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor of the file which has already been opened.

> int sz is the size, in bytes, to be used for the buffer.

> ##### Example

> filebuf *buf = filebuf_open(fd, FILE_BUFFERSIZE);
> if (!buf) {
> system_fclose(fd);
> }

> ##### See also

> filebuf_getc, filebuf_buf2sd, filebuf_close, filebuf_open_nostat

> ### filebuf_open_nostat

> The filebuf_open_nostat function opens a new file buffer for a previously opened file. It returns a new buffer structure. Buffered files provide more efficient file access by guaranteeing the use of buffered file I/O in environments where it is not supported by the operating system.

> This function is the same filebuf_open, but is more efficient, since it does not need to call the request_stat_path function. It requires that the stat information be passed in.

> ##### Syntax

> filebuf* filebuf_open_nostat(SYS_FILE fd, int sz,
> struct stat *finfo);

> ##### Returns

> A pointer to a new buffer structure to hold the data, if successful or NULL if no buffer could be opened.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor of the file which has already been opened.

> int sz is the size, in bytes, to be used for the buffer.

> struct stat *finfo is the file information of the file. Before calling the filebuf_open_nostat function, you must call the request_stat_path function to retrieve the file information.

> ##### Example

> filebuf *buf = filebuf_open_nostat(fd, FILE_BUFFERSIZE, &finfo);
> if (!buf) {
> system_fclose(fd);
> }

> ##### See also

> filebuf_close, filebuf_open, filebuf_getc, filebuf_buf2sd

> ### FREE

> The FREE macro is a platform-independent substitute for the C library routine free. It deallocates the space previously allocated by MALLOC, CALLOC, or STRDUP from the request’s memory pool.

> ##### Syntax

> FREE(void *ptr);

> ##### Returns

> void

> ##### Parameters

> void *ptr is a (void *) pointer to a block of memory. If the pointer is not one created by MALLOC, CALLOC, or STRDUP, the behavior is undefined.

> ##### Example

> char *name;
> name = (char *) MALLOC(256);
> ...
> FREE(name);

> ##### See also

> MALLOC, CALLOC, REALLOC, STRDUP, PERM_MALLOC, PERM_FREE, PERM_REALLOC, PERM_STRDUP

> ### func_exec

> The func_exec function executes the function named by the fn entry in a specified pblock. If the function name is not found, it logs the error and returns REQ_ABORTED.

> You can use this function to execute a built-in server application function (SAF) by identifying it in the pblock.

> ##### Syntax

> int func_exec(pblock *pb, Session *sn, Request *rq);

> ##### Returns

> The value returned by the executed function or the constant REQ_ABORTED if no function was executed.

> ##### Parameters

> pblock pb is the pblock containing the function name (fn) and parameters.

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> ##### See also

> log_error

> ### func_find

> The func_find function returns a pointer to the function specified by name. If the function does not exist, it returns NULL.

> ##### Syntax

> FuncPtr func_find(char *name);

> ##### Returns

> A pointer to the chosen function, suitable for dereferencing or NULL if the function could not be found.

> ##### Parameters

> char *name is the name of the function.

> ##### Example

> /* this block of code does the same thing as func_exec */
> char *afunc = pblock_findval("afunction", pb);
> FuncPtr afnptr = func_find(afunc);
> if (afnptr)
> return (afnptr)(pb, sn, rq);

> ##### See also

> func_exec

> ##

> L

> ### log_error

> The log_error function creates an entry in a server log, recording the date, the severity, and a specified text.

> ##### Syntax

> int log_error(int degree, char *func, Session *sn, Request *rq, char *fmt, ...);

> ##### Returns

> 0 if the log entry was created or -1 if the log entry was not created.

> ##### Parameters

> int degree specifies the severity of the error. It must be one of the following constants:

> LOG_WARN—warning
> LOG_MISCONFIG—a syntax error or permission violation
> LOG_SECURITY—an authentication failure or 403 error from a host
> LOG_FAILURE—an internal problem
> LOG_CATASTROPHE—a non-recoverable server error
> LOG_INFORM—an informational message

> char *func is the name of the function where the error has occurred.

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> char *fmt specifies the format for the printf function that delivers the message.

> ... represents a sequence of parameters for the printf function.

> ##### Example

> log_error(LOG_WARN, "send-file", sn, rq,
> "error opening buffer from %s (%s)"), path,
> system_errmsg(fd));

> ##### See also

> func_exec

> ##

> M

> ### MALLOC

> The MALLOC macro is a platform-independent substitute for the C library routine malloc. It normally allocates from the request’s memory pool. If pooled memory has been disabled in the configuration file (with the pool-init built-in SAF), PERM_MALLOC and MALLOC both obtain their memory from the system heap.

> ##### Syntax

> void *MALLOC(int size)

> ##### Returns

> A void pointer to a block of memory.

> ##### Parameters

> int size is the number of bytes to allocate.

> ##### Example

> /* Allocate 256 bytes for a name */
> char *name;
> name = (char *) MALLOC(256);

> ##### See also

> FREE, CALLOC, REALLOC, STRDUP, PERM_MALLOC, PERM_FREE, PERM_CALLOC, PERM_REALLOC, PERM_STRDUP

> ##

> N

> ### net_ip2host

> The net_ip2host function transforms a textual IP address into a fully-qualified domain name and returns it.

> Note | This function works only if the DNS directive is enabled in the init.conf file. For more information, see the Sun Java System Application Server Administrator’s Configuration File Reference.

> ##### Syntax

> char *net_ip2host(char *ip, int verify);

> ##### Returns

> A new string containing the fully-qualified domain name, if the transformation was accomplished or NULL if the transformation was not accomplished.

> ##### Parameters

> char *ip is the IP (Internet Protocol) address as a character string in dotted-decimal notation: nnn.nnn.nnn.nnn

> int verify, if non-zero, specifies that the function should verify the fully-qualified domain name. Though this requires an extra query, you should use it when checking access control.

> ### net_read

> The net_read function reads bytes from a specified socket into a specified buffer. The function waits to receive data from the socket until either at least one byte is available in the socket or the specified time has elapsed.

> ##### Syntax

> int net_read (SYS_NETFD sd, char *buf, int sz, int timeout);

> ##### Returns

> The number of bytes read, which will not exceed the maximum size, sz. A negative value is returned if an error has occurred, in which case errno is set to the constant ETIMEDOUT if the operation did not complete before timeout seconds elapsed.

> ##### Parameters

> SYS_NETFD sd is the platform-independent socket descriptor.

> char *buf is the buffer to receive the bytes.

> int sz is the maximum number of bytes to read.

> int timeout is the number of seconds to allow for the read operation before returning. The purpose of timeout is not to return because not enough bytes were read in the given time, but to limit the amount of time devoted to waiting until some data arrives.

> ##### See also

> net_write

> ### net_write

> The net_write function writes a specified number of bytes to a specified socket from a specified buffer. It returns the number of bytes written.

> ##### Syntax

> int net_write(SYS_NETFD sd, char *buf, int sz);

> ##### Returns

> The number of bytes written, which may be less than the requested size if an error occurred.

> ##### Parameters

> SYS_NETFD sd is the platform-independent socket descriptor.

> char *buf is the buffer containing the bytes.

> int sz is the number of bytes to write.

> ##### Example

> if (net_write(sn->csd, FIRSTMSG, strlen(FIRSTMSG)) == IO_ERROR)
> return REQ_EXIT;

> ##### See also

> net_read

> ### netbuf_buf2sd

> The netbuf_buf2sd function sends a buffer to a socket. You can use this function to send data from IPC pipes to the client.

> ##### Syntax

> int netbuf_buf2sd(netbuf *buf, SYS_NETFD sd, int len);

> ##### Returns

> The number of bytes transferred to the socket, if successful or the constant IO_ERROR if unsuccessful

> ##### Parameters

> netbuf *buf is the buffer to send.

> SYS_NETFD sd is the platform-independent identifier of the socket.

> int len is the length of the buffer.

> ##### See also

> netbuf_close, netbuf_getc, netbuf_grab, netbuf_open

> ### netbuf_close

> The netbuf_close function deallocates a network buffer and closes its associated files. Use this function when you need to deallocate the network buffer and close the socket.

> You should never close the netbuf parameter in a Session structure.

> ##### Syntax

> void netbuf_close(netbuf *buf);

> ##### Returns

> void

> ##### Parameters

> netbuf *buf is the buffer to close.

> ##### See also

> netbuf_buf2sd, netbuf_getc, netbuf_grab, netbuf_open

> ### netbuf_getc

> The netbuf_getc function retrieves a character from the cursor position of the network buffer specified by b.

> ##### Syntax

> netbuf_getc(netbuf b);

> ##### Returns

> The integer representing the character, if one was retrieved or the constant IO_EOF or IO_ERROR, for end of file or error

> ##### Parameters

> netbuf b is the buffer from which to retrieve one character.

> ##### See also

> netbuf_buf2sd, netbuf_close, netbuf_grab, netbuf_open

> ### netbuf_grab

> The netbuf_grab function reads sz number of bytes from the network buffer’s (buf) socket into the network buffer. If the buffer is not large enough it is resized. The data can be retrieved from buf->inbuf on success.

> This function is used by the function netbuf_buf2sd.

> ##### Syntax

> int netbuf_grab(netbuf *buf, int sz);

> ##### Returns

> The number of bytes actually read (between 1 and sz), if the operation was successful or the constant IO_EOF or IO_ERROR, for end of file or error

> ##### Parameters

> netbuf *buf is the buffer to read into.

> int sz is the number of bytes to read.

> ##### See also

> netbuf_buf2sd, netbuf_close, netbuf_getc, netbuf_open

> ### netbuf_open

> The netbuf_open function opens a new network buffer and returns it. You can use netbuf_open to create a netbuf structure and start using buffered I/O on a socket.

> ##### Syntax

> netbuf* netbuf_open(SYS_NETFD sd, int sz);

> ##### Returns

> A pointer to a new netbuf structure (network buffer)

> ##### Parameters

> SYS_NETFD sd is the platform-independent identifier of the socket.

> int sz is the number of characters to allocate for the network buffer.

> ##### See also

> netbuf_buf2sd, netbuf_close, netbuf_getc, netbuf_grab

> ##

> P

> ### param_create

> The param_create function creates a pb_param structure containing a specified name and value. The name and value are copied. Use this function to prepare a pb_param structure to be used in calls to pblock routines such as pblock_pinsert.

> ##### Syntax

> pb_param *param_create(char *name, char *value);

> ##### Returns

> A pointer to a new pb_param structure.

> ##### Parameters

> char *name is the string containing the name.

> char *value is the string containing the value.

> ##### Example

> pb_param *newpp = param_create("content-type","text/plain");
> pblock_pinsert(newpp, rq->srvhdrs);

> ##### See also

> param_free, pblock_pinsert, pblock_remove

> ### param_free

> The param_free function frees the pb_param structure specified by pp and its associated structures. Use the param_free function to dispose a pb_param after removing it from a pblock with pblock_remove.

> ##### Syntax

> int param_free(pb_param *pp);

> ##### Returns

> 1 if the parameter was freed or 0 if the parameter was NULL.

> ##### Parameters

> pb_param *pp is the name-value pair stored in a pblock.

> ##### Example

> if (param_free(pblock_remove("content-type", rq-srvhdrs)))
> return; /* we removed it */

> ##### See also

> param_create, pblock_pinsert, pblock_remove

> ### pblock_copy

> The pblock_copy function copies the entries of the source pblock and adds them into the destination pblock. Any previous entries in the destination pblock are left intact.

> ##### Syntax

> void pblock_copy(pblock *src, pblock *dst);

> ##### Returns

> void

> ##### Parameters

> pblock *src is the source pblock.

> pblock *dst is the destination pblock.

> Names and values are newly allocated so that the original pblock may be freed, or the new pblock changed without affecting the original pblock.

> ##### See also

> pblock_create, pblock_dup, pblock_free, pblock_find, pblock_findval, pblock_remove, pblock_nvinsert

> ### pblock_create

> The pblock_create function creates a new pblock. The pblock maintains an internal hash table for fast name-value pair lookups.

> ##### Syntax

> pblock *pblock_create(int n);

> ##### Returns

> A pointer to a newly allocated pblock.

> ##### Parameters

> int n is the size of the hash table (number of name-value pairs) for the pblock.

> ##### See also

> pblock_copy, pblock_dup, pblock_find, pblock_findval, pblock_free, pblock_nvinsert, pblock_remove

> ### pblock_dup

> The pblock_dup function duplicates a pblock. It is equivalent to a sequence of pblock_create and pblock_copy.

> ##### Syntax

> pblock *pblock_dup(pblock *src);

> ##### Returns

> A pointer to a newly allocated pblock.

> ##### Parameters

> pblock *src is the source pblock.

> ##### See also

> pblock_create, pblock_find, pblock_findval, pblock_free, pblock_find, pblock_remove, pblock_nvinsert

> ### pblock_find

> The pblock_find function finds a specified name-value pair entry in a pblock, and returns the pb_param structure. If you only want the value associated with the name, use the pblock_findval function.

> This function is implemented as a macro.

> ##### Syntax

> pb_param *pblock_find(char *name, pblock *pb);

> ##### Returns

> A pointer to the pb_param structure, if one was found or NULL if name was not found.

> ##### Parameters

> char *name is the name of a name-value pair.

> pblock *pb is the pblock to be searched.

> ##### See also

> pblock_copy, pblock_dup, pblock_findval, pblock_free, pblock_nvinsert, pblock_remove

> ### pblock_findval

> The pblock_findval function finds the value of a specified name in a pblock. If you just want the pb_param structure of the pblock, use the pblock_find function.

> The pointer returned is a pointer into the pblock. Do not FREE it. If you want to modify it, do a STRDUP and modify the copy.

> ##### Syntax

> char *pblock_findval(char *name, pblock *pb);

> ##### Returns

> A string containing the value associated with the name or NULL if no match was found

> ##### Parameters

> char *name is the name of a name-value pair.

> pblock *pb is the pblock to be searched.

> ##### Example

> see pblock_nvinsert.

> ##### See also

> pblock_create, pblock_copy, pblock_find, pblock_free, pblock_nvinsert, pblock_remove, request_header

> ### pblock_free

> The pblock_free function frees a specified pblock and any entries inside it. If you want to save a variable in the pblock, remove the variable using the function pblock_remove and save the resulting pointer.

> ##### Syntax

> void pblock_free(pblock *pb);

> ##### Returns

> void

> ##### Parameters

> pblock *pb is the pblock to be freed.

> ##### See also

> pblock_copy, pblock_create, pblock_dup, pblock_find, pblock_findval, pblock_nvinsert, pblock_remove

> ### pblock_nninsert

> The pblock_nninsert function creates a new entry with a given name and a numeric value in the specified pblock. The numeric value is first converted into a string. The name and value parameters are copied.

> ##### Syntax

> pb_param *pblock_nninsert(char *name, int value, pblock *pb);

> ##### Returns

> A pointer to the new pb_param structure.

> ##### Parameters

> char *name is the name of the new entry.

> int value is the numeric value being inserted into the pblock. This parameter must be an integer. If the value you assign is not a number, then instead use the function pblock_nvinsert to create the parameter.

> pblock *pb is the pblock into which the insertion occurs.

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nvinsert, pblock_remove, pblock_str2pblock

> ### pblock_nvinsert

> The pblock_nvinsert function creates a new entry with a given name and character value in the specified pblock. The name and value parameters are copied.

> ##### Syntax

> pb_param *pblock_nvinsert(char *name, char *value, pblock *pb);

> ##### Returns

> A pointer to the newly allocated pb_param structure

> ##### Parameters

> char *name is the name of the new entry.

> char *value is the string value of the new entry.

> pblock *pb is the pblock into which the insertion occurs.

> ##### Example

> pblock_nvinsert("content-type", "text/html", rq->srvhdrs);

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nninsert, pblock_remove, pblock_str2pblock

> ### pblock_pb2env

> The pblock_pb2env function copies a specified pblock into a specified environment. The function creates one new environment entry for each name-value pair in the pblock. Use this function to send pblock entries to a program that you are going to execute.

> ##### Syntax

> char **pblock_pb2env(pblock *pb, char **env);

> ##### Returns

> A pointer to the environment.

> ##### Parameters

> pblock *pb is the pblock to be copied.

> char **env is the environment into which the pblock is to be copied.

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nvinsert, pblock_remove, pblock_str2pblock

> ### pblock_pblock2str

> The pblock_pblock2str function copies all parameters of a specified pblock into a specified string. The function allocates additional non-heap space for the string if needed.

> Use this function to stream the pblock for archival and other purposes.

> ##### Syntax

> char *pblock_pblock2str(pblock *pb, char *str);

> ##### Returns

> The new version of the str parameter. If str is NULL, this is a new string; otherwise it is a reallocated string. In either case, it is allocated from the request’s memory pool.

> ##### Parameters

> pblock *pb is the pblock to be copied.

> char *str is the string into which the pblock is to be copied. It must have been allocated by MALLOC or REALLOC, not by PERM_MALLOC or PERM_REALLOC (which allocate from the system heap).

> Each name-value pair in the string is separated from its neighbor pair by a space and is in the format name="value".

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nvinsert, pblock_remove, pblock_str2pblock

> ### pblock_pinsert

> The function pblock_pinsert inserts a pb_param structure into a pblock.

> ##### Syntax

> void pblock_pinsert(pb_param *pp, pblock *pb);

> ##### Returns

> void

> ##### Parameters

> pb_param *pp is the pb_param structure to insert.

> pblock *pb is the pblock.

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nvinsert, pblock_remove, pblock_str2pblock

> ### pblock_remove

> The pblock_remove function removes a specified name-value entry from a specified pblock. If you use this function you should eventually call param_free in order to deallocate the memory used by the pb_param structure.

> ##### Syntax

> pb_param *pblock_remove(char *name, pblock *pb);

> ##### Returns

> A pointer to the named pb_param structure, if it was found or NULL if the named pb_param was not found.

> ##### Parameters

> char *name is the name of the pb_param to be removed.

> pblock *pb is the pblock from which the name-value entry is to be removed.

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nvinsert, param_create, param_free

> ### pblock_str2pblock

> The pblock_str2pblock function scans a string for parameter pairs, adds them to a pblock, and returns the number of parameters added.

> ##### Syntax

> int pblock_str2pblock(char *str, pblock *pb);

> ##### Returns

> The number of parameter pairs added to the pblock, if any or -1 if an error occurred

> ##### Parameters

> char *str is the string to be scanned.

> The name-value pairs in the string can have the format name=value or name="value".

> All back slashes (\) must be followed by a literal character. If string values are found with no unescaped = signs (no name=), it assumes the names 1, 2, 3, and so on, depending on the string position. For example, if pblock_str2pblock finds "some strings together", the function treats the strings as if they appeared in name-value pairs as 1="some" 2="strings" 3="together".

> pblock *pb is the pblock into which the name-value pairs are stored.

> ##### See also

> pblock_copy, pblock_create, pblock_find, pblock_free, pblock_nvinsert, pblock_remove, pblock_pblock2str

> ### PERM_CALLOC

> The PERM_CALLOC macro is a platform-independent substitute for the C library routine calloc. It allocates num*size bytes of memory that persists after the request that is being processed has been completed. If pooled memory has been disabled in the configuration file (with the pool-init built-in SAF), PERM_CALLOC and CALLOC both obtain their memory from the system heap.

> ##### Syntax

> void *PERM_CALLOC(int num, int size)

> ##### Returns

> A void pointer to a block of memory

> ##### Parameters

> int num is the number of elements to allocate.

> int size is the size in bytes of each element.

> ##### Example

> /* Allocate 256 bytes for a name */
> char **name;
> name = (char **) PERM_CALLOC(100, sizeof(char *));

> ##### See also

> PERM_FREE, PERM_STRDUP, PERM_MALLOC, PERM_REALLOC, MALLOC, FREE, CALLOC, STRDUP, REALLOC

> ### PERM_FREE

> The PERM_FREE macro is a platform-independent substitute for the C library routine free. It deallocates the persistent space previously allocated by PERM_MALLOC, PERM_CALLOC, or PERM_STRDUP. If pooled memory has been disabled in the configuration file (with the pool-init built-in SAF), PERM_FREE and FREE both deallocate memory in the system heap.

> ##### Syntax

> PERM_FREE(void *ptr);

> ##### Returns

> void

> ##### Parameters

> void *ptr is a (void *) pointer to block of memory. If the pointer is not one created by PERM_MALLOC, PERM_CALLOC, or PERM_STRDUP, the behavior is undefined.

> ##### Example

> char *name;
> name = (char *) PERM_MALLOC(256);
> ...
> PERM_FREE(name);

> ##### See also

> FREE, MALLOC, CALLOC, REALLOC, STRDUP, PERM_MALLOC, PERM_CALLOC, PERM_REALLOC, PERM_STRDUP

> ### PERM_MALLOC

> The PERM_MALLOC macro is a platform-independent substitute for the C library routine malloc. It provides allocation of memory that persists after the request that is being processed has been completed. If pooled memory has been disabled in the configuration file (with the pool-init built-in SAF), PERM_MALLOC and MALLOC both obtain their memory from the system heap.

> ##### Syntax

> void *PERM_MALLOC(int size)

> ##### Returns

> A void pointer to a block of memory

> ##### Parameters

> int size is the number of bytes to allocate.

> ##### Example

> /* Allocate 256 bytes for a name */
> char *name;
> name = (char *) PERM_MALLOC(256);

> ##### See also

> PERM_FREE, PERM_STRDUP, PERM_CALLOC, PERM_REALLOC, MALLOC, FREE, CALLOC, STRDUP, REALLOC

> ### PERM_REALLOC

> The PERM_REALLOC macro is a platform-independent substitute for the C library routine realloc. It changes the size of a specified memory block that was originally created by MALLOC, CALLOC, or STRDUP. The contents of the object remains unchanged up to the lesser of the old and new sizes. If the new size is larger, the new space is uninitialized.

> ##### Warning

> Calling PERM_REALLOC for a block that was allocated with MALLOC, CALLOC, or STRDUP will not work.

> ##### Syntax

> void *PERM_REALLOC(vod *ptr, int size)

> ##### Returns

> A void pointer to a block of memory

> ##### Parameters

> void *ptr a void pointer to a block of memory created by PERM_MALLOC, PERM_CALLOC, or PERM_STRDUP.

> int size is the number of bytes to which the memory block should be resized.

> ##### Example

> char *name;
> name = (char *) PERM_MALLOC(256);
> if (NotBigEnough())
> name = (char *) PERM_REALLOC(512);

> ##### See also

> PERM_MALLOC, PERM_FREE, PERM_CALLOC, PERM_STRDUP, MALLOC, FREE, STRDUP, CALLOC, REALLOC

> ### PERM_STRDUP

> The PERM_STRDUP macro is a platform-independent substitute for the C library routine strdup. It creates a new copy of a string in memory that persists after the request that is being processed has been completed. If pooled memory has been disabled in the configuration file (with the pool-init built-in SAF), PERM_STRDUP and STRDUP both obtain their memory from the system heap.

> The PERM_STRDUP routine is functionally equivalent to

> newstr = (char *) PERM_MALLOC(strlen(str) + 1); strcpy(newstr, str);

> A string created with PERM_STRDUP should be disposed with PERM_FREE.

> ##### Syntax

> char *PERM_STRDUP(char *ptr);

> ##### Returns

> A pointer to the new string

> ##### Parameters

> char *ptr is a pointer to a string.

> ##### See also

> PERM_MALLOC, PERM_FREE, PERM_CALLOC, PERM_REALLOC, MALLOC, FREE, STRDUP, CALLOC, REALLOC

> ### prepare_nsapi_thread

> The prepare_nsapi_thread function allows threads that are not created by the server to act like server-created threads. This function must be called before any NSAPI functions are called from a thread that is not server-created.

> ##### Syntax

> void prepare_nsapi_thread(Request *rq, Session *sn);

> ##### Returns

> void

> ##### Parameters

> Request *rq is the Request.

> Session *sn is the Session.

> The Request and Session parameters are the same as the ones passed into your SAF.

> ##### See also

> protocol_start_response

> ### protocol_dump822

> The protocol_dump822 function prints headers from a specified pblock into a specific buffer, with a specified size and position. Use this function to serialize the headers so that they can be sent, for example, in a mail message.

> ##### Syntax

> char *protocol_dump822(pblock *pb, char *t, int *pos, int tsz);

> ##### Returns

> A pointer to the buffer, which will be reallocated if necessary.

> The function also modifies *pos to the end of the headers in the buffer.

> ##### Parameters

> pblock *pb is the pblock structure.

> char *t is the buffer, allocated with MALLOC, CALLOC, or STRDUP.

> int *pos is the position within the buffer at which the headers are to be dumped.

> int tsz is the size of the buffer.

> ##### See also

> protocol_start_response, protocol_status

> ### protocol_set_finfo

> The protocol_set_finfo function retrieves the content-length and last-modified date from a specified stat structure and adds them to the response headers (rq->srvhdrs). Call protocol_set_finfo before calling protocol_start_response.

> ##### Syntax

> int protocol_set_finfo(Session *sn, Request *rq, struct stat *finfo);

> ##### Returns

> The constant REQ_PROCEED if the request can proceed normally or the constant REQ_ABORTED if the function should treat the request normally, but not send any output to the client

> ##### Parameters

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> stat *finfo is the stat structure for the file.

> The stat structure contains the information about the file from the file system. You can get the stat structure info using request_stat_path.

> ##### See also

> protocol_start_response, protocol_status

> ### protocol_start_response

> The protocol_start_response function initiates the HTTP response for a specified session and request. If the protocol version is HTTP/0.9, the function does nothing, because that version has no concept of status. If the protocol version is HTTP/1.0, the function sends a status line followed by the response headers. Use this function to set up HTTP and prepare the client and server to receive the body (or data) of the response.

> ##### Syntax

> int protocol_start_response(Session *sn, Request *rq);

> ##### Returns

> The constant REQ_PROCEED if the operation succeeded, in which case you should send the data you were preparing to send.

> The constant REQ_NOACTION if the operation succeeded, but the request method was HEAD in which case no data should be sent to the client.

> The constant REQ_ABORTED if the operation did not succeed.

> ##### Parameters

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> ##### Example

> /* A noaction response from this function means the request was HEAD */
> if (protocol_start_response(sn, rq) == REQ_NOACTION) {
> filebuf_close(groupbuf); /* close our file*/
> return REQ_PROCEED;
> }

> ##### See also

> protocol_status

> ### protocol_status

> The protocol_status function sets the session status to indicate whether an error condition occurred. If the reason string is NULL, the server attempts to find a reason string for the given status code. If it finds none, it returns “Unknown reason.” The reason string is sent to the client in the HTTP response line. Use this function to set the status of the response before calling the function protocol_start_response.

> For the complete list of valid status code constants, please refer to the file nsapi.h in the server distribution

> ##### Syntax

> void protocol_status(Session *sn, Request *rq, int n, char *r);

> ##### Returns

> void, but it sets values in the Session/Request designated by sn/rq for the status code and the reason string

> ##### Parameters

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> int n is one of the status code constants above.

> char *r is the reason string.

> ##### Example

> /* if we find extra path-info, the URL was bad so tell the */
> /* browser it was not found */
> if (t = pblock_findval("path-info", rq->vars)) {
> protocol_status(sn, rq, PROTOCOL_NOT_FOUND, NULL);
> log_error(LOG_WARN, "function-name", sn, rq, "%s not found",
> path);
> return REQ_ABORTED;
> }

> ##### See also

> protocol_start_response

> ### protocol_uri2url

> The protocol_uri2url function takes strings containing the given URI prefix and URI suffix, and creates a newly-allocated fully qualified URL in the form http://(server):(port)(prefix)(suffix). See protocol_uri2url_dynamic.

> If you want to omit either the URI prefix or suffix, use "" instead of NULL as the value for either parameter.

> ##### Syntax

> char *protocol_uri2url(char *prefix, char *suffix);

> ##### Returns

> A new string containing the URL

> ##### Parameters

> char *prefix is the prefix.

> char *suffix is the suffix.

> ##### See also

> protocol_start_response, protocol_status, pblock_nvinsert, protocol_uri2url_dynamic

> ### protocol_uri2url_dynamic

> The protocol_uri2url function takes strings containing the given URI prefix and URI suffix, and creates a newly-allocated fully qualified URL in the form http://(server):(port)(prefix)(suffix).

> If you want to omit either the URI prefix or suffix, use "" instead of NULL as the value for either parameter.

> The protocol_uri2url_dynamic function is similar to the protocol_uri2url function but should be used whenever the Session and Request structures are available. This ensures that the URL that it constructs refers to the host that the client specified.

> ##### Syntax

> char *protocol_uri2url(char *prefix, char *suffix, Session *sn, Request *rq);

> ##### Returns

> A new string containing the URL

> ##### Parameters

> char *prefix is the prefix.

> char *suffix is the suffix.

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> ##### See also

> protocol_start_response, protocol_status, protocol_uri2url

> ##

> R

> ### REALLOC

> The REALLOC macro is a platform-independent substitute for the C library routine realloc. It changes the size of a specified memory block that was originally created by MALLOC, CALLOC, or STRDUP. The contents of the object remains unchanged up to the lesser of the old and new sizes. If the new size is larger, the new space is uninitialized.

> ##### Warning

> Calling REALLOC for a block that was allocated with PERM_MALLOC, PERM_CALLOC, or PERM_STRDUP will not work.

> ##### Syntax

> void *REALLOC(void *ptr, int size);

> ##### Returns

> A pointer to the new space if the request could be satisfied.

> ##### Parameters

> void *ptr is a (void *) pointer to a block of memory. If the pointer is not one created by MALLOC, CALLOC, or STRDUP, the behavior is undefined.

> int size is the number of bytes to allocate.

> ##### Example

> char *name;
> name = (char *) MALLOC(256);
> if (NotBigEnough())
> name = (char *) REALLOC(512);

> ##### See also

> MALLOC, FREE, STRDUP, CALLOC, PERM_MALLOC, PERM_FREE, PERM_REALLOC, PERM_CALLOC, PERM_STRDUP

> ### request_get_vs

> The request_get_vs function finds the VirtualServer* to which a request is directed.

> The returned VirtualServer* is valid only for the current request. To retrieve a virtual server ID that is valid across requests, use vs_get_id.

> ##### Syntax

> const VirtualServer* request_get_vs(Request* rq);

> ##### Returns

> The VirtualServer* to which the request is directed.

> ##### Parameters

> Request *rq is the request for which the VirtualServer* is returned.

> ##### See also

> vs_get_id

> ### request_header

> The request_header function finds an entry in the pblock containing the client’s HTTP request headers (rq->headers). You must use this function rather than pblock_findval when accessing the client headers since the server may begin processing the request before the headers have been completely read.

> ##### Syntax

> int request_header(char *name, char **value, Session *sn, Request *rq);

> ##### Returns

> A result code, REQ_PROCEED if the header was found, REQ_ABORTED if the header was not found, REQ_EXIT if there was an error reading from the client.

> ##### Parameters

> char *name is the name of the header.

> char **value is the address where the function will place the value of the specified header. If none is found, the function stores a NULL.

> Session *sn is the Session.

> Request *rq is the Request.

> The Session and Request parameters are the same as the ones passed into your SAF.

> ##### See also

> request_create, request_free

> ### request_stat_path

> The request_stat_path function returns the file information structure for a specified path or, if none is specified, the path entry in the vars pblock in the specified Request structure. If the resulting file name points to a file that the server can read, request_stat_path returns a new file information structure. This structure contains information on the size of the file, its owner, when it was created, and when it was last modified.

> You should use request_stat_path to retrieve information on the file you are currently accessing (instead of calling stat directly), because this function keeps track of previous calls for the same path and returns its cached information.

> ##### Syntax

> struct stat *request_stat_path(char *path, Request *rq);

> ##### Returns

> Returns a pointer to the file information structure for the file named by the path parameter. Do not free this structure. Returns NULL if the file is not valid or the server cannot read it. In this case, it also leaves an error message describing the problem in rq->staterr.

> ##### Parameters

> char *path is the string containing the name of the path. If the value of path is NULL, the function uses the path entry in the vars pblock in the Request structure denoted by rq.

> Request *rq is the request identifier for a server application function call.

> ##### Example

> fi = request_stat_path(path, rq);

> ##### See also

> request_create, request_free, request_header

> ### request_translate_uri

> The request_translate_uri function performs virtual to physical mapping on a specified URI during a specified session. Use this function when you want to determine which file would be sent back if a given URI is accessed.

> ##### Syntax

> char *request_translate_uri(char *uri, Session *sn);

> ##### Returns

> A path string, if it performed the mapping or NULL if it could not perform the mapping

> ##### Parameters

> char *uri is the name of the URI.

> Session *sn is the Session parameter that is passed into your SAF.

> ##### See also

> request_create, request_free, request_header

> ##

> S

> ### session_dns

> The session_dns function resolves the IP address of the client associated with a specified session into its DNS name. It returns a newly allocated string. You can use session_dns to change the numeric IP address into something more readable.

> The session_maxdns function verifies that the client is who it claims to be; the session_dns function does not perform this verification.

> Note | This function works only if the DNS directive is enabled in the init.conf file. For more information, see the Sun Java System Application Server Administrator’s Configuration File Reference.

> ##### Syntax

> char *session_dns(Session *sn);

> ##### Returns

> A string containing the host name or NULL if the DNS name cannot be found for the IP address

> ##### Parameters

> Session *sn is the Session.

> The Session is the same as the one passed to your SAF.

> ### session_maxdns

> The session_maxdns function resolves the IP address of the client associated with a specified session into its DNS name. It returns a newly allocated string. You can use session_maxdns to change the numeric IP address into something more readable.

> Note | This function works only if the DNS directive is enabled in the init.conf file. For more information, see the Sun Java System Application Server Administrator’s Configuration File Reference.

> ##### Syntax

> char *session_maxdns(Session *sn);

> ##### Returns

> A string containing the host name or NULL if the DNS name cannot be found for the IP address

> ##### Parameters

> Session *sn is the Session.

> The Session is the same as the one passed to your SAF.

> ### shexp_casecmp

> The shexp_casecmp function validates a specified shell expression and compares it with a specified string. It returns one of three possible values representing match, no match, and invalid comparison. The comparison (in contrast to that of the shexp_cmp function) is not case-sensitive.

> Use this function if you have a shell expression like *.sun.com and you want to make sure that a string matches it, such as foo.sun.com.

> For information about wildcard patterns you can use in this function, see Appendix B, “Wildcard Patterns.”

> ##### Syntax

> int shexp_casecmp(char *str, char *exp);

> ##### Returns

> 0 if a match was found.

> 1 if no match was found.

> -1 if the comparison resulted in an invalid expression.

> ##### Parameters

> char *str is the string to be compared.

> char *exp is the shell expression (wildcard pattern) to compare against.

> ##### See also

> shexp_cmp, shexp_match, shexp_valid

> ### shexp_cmp

> The shexp_casecmp function validates a specified shell expression and compares it with a specified string. It returns one of three possible values representing match, no match, and invalid comparison. The comparison (in contrast to that of the shexp_casecmp function) is case-sensitive.

> Use this function if you have a shell expression like *.sun.com and you want to make sure that a string matches it, such as foo.sun.com.

> For information about wildcard patterns you can use in this function, see Appendix B, “Wildcard Patterns.”

> ##### Syntax

> int shexp_cmp(char *str, char *exp);

> ##### Returns

> 0 if a match was found.

> 1 if no match was found.

> -1 if the comparison resulted in an invalid expression.

> ##### Parameters

> char *str is the string to be compared.

> char *exp is the shell expression (wildcard pattern) to compare against.

> ##### Example

> /* Use wildcard match to see if this path is one we want */
> char *path;
> char *match = "/usr/sun/*";
> if (shexp_cmp(path, match) != 0)
> return REQ_NOACTION; /* no match */

> ##### See also

> shexp_casecmp, shexp_match, shexp_valid

> ### shexp_match

> The shexp_match function compares a specified pre-validated shell expression against a specified string. It returns one of three possible values representing match, no match, and invalid comparison. The comparison (in contrast to that of the shexp_casecmp function) is case-sensitive.

> The shexp_match function doesn’t perform validation of the shell expression; instead the function assumes that you have already called shexp_valid.

> Use this function if you have a shell expression like *.sun.com and you want to make sure that a string matches it, such as foo.sun.com.

> For information about wildcard patterns you can use in this function, see Appendix B, “Wildcard Patterns.”

> ##### Syntax

> int shexp_match(char *str, char *exp);

> ##### Returns

> 0 if a match was found.

> 1 if no match was found.

> -1 if the comparison resulted in an invalid expression.

> ##### Parameters

> char *str is the string to be compared.

> char *exp is the pre-validated shell expression (wildcard pattern) to compare against.

> ##### See also

> shexp_casecmp, shexp_cmp, shexp_valid

> ### shexp_valid

> The shexp_valid function validates a specified shell expression named by exp. Use this function to validate a shell expression before using the function shexp_match to compare the expression with a string.

> For information about wildcard patterns you can use in this function, see Appendix B, “Wildcard Patterns.”

> ##### Syntax

> int shexp_valid(char *exp);

> ##### Returns

> The constant NON_SXP if exp is a standard string.

> The constant INVALID_SXP if exp is a shell expression, but invalid.

> The constant VALID_SXP if exp is a valid shell expression.

> ##### Parameters

> char *exp is the shell expression (wildcard pattern) to be validated.

> ##### See also

> shexp_casecmp, shexp_match, shexp_cmp

> ### STRDUP

> The STRDUP macro is a platform-independent substitute for the C library routine strdup. It creates a new copy of a string in the request’s memory pool.

> The STRDUP routine is functionally equivalent to:

> newstr = (char *) MALLOC(strlen(str) + 1); strcpy(newstr, str);

> A string created with STRDUP should be disposed with FREE.

> ##### Syntax

> char *STRDUP(char *ptr);

> ##### Returns

> A pointer to the new string.

> ##### Parameters

> char *ptr is a pointer to a string.

> ##### Example

> char *name1 = "MyName";
> char *name2 = STRDUP(name1);

> ##### See also

> MALLOC, FREE, CALLOC, REALLOC, PERM_MALLOC, PERM_FREE, PERM_CALOC, PERM_REALLOC, PERM_STRDUP

> ### system_errmsg

> The system_errmsg function returns the last error that occurred from the most recent system call. This function is implemented as a macro that returns an entry from the global array sys_errlist. Use this macro to help with I/O error diagnostics.

> ##### Syntax

> char *system_errmsg(int param1);

> ##### Returns

> A string containing the text of the latest error message that resulted from a system call. Do not FREE this string.

> ##### Parameters

> int param1 is reserved, and should always have the value 0.

> ##### See also

> system_fopenRO, system_fopenRW, system_fopenWA, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_fclose

> The system_fclose function closes a specified file descriptor. The system_fclose function must be called for every file descriptor opened by any of the system_fopen functions.

> ##### Syntax

> int system_fclose(SYS_FILE fd);

> ##### Returns

> 0 if the close succeeded or the constant IO_ERROR if the close failed.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> ##### Example

> SYS_FILE logfd;
> system_fclose(logfd);

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock

> ### system_flock

> The system_flock function locks the specified file against interference from other processes. Use system_flock if you do not want other processes using the file you currently have open. Overusing file locking can cause performance degradation and possibly lead to deadlocks.

> ##### Syntax

> int system_flock(SYS_FILE fd);

> ##### Returns

> The constant IO_OKAY if the lock succeeded or the constant IO_ERROR if the lock failed

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_ulock, system_fclose

> ### system_fopenRO

> The system_fopenRO function opens the file identified by path in read-only mode and returns a valid file descriptor. Use this function to open files that will not be modified by your program. In addition, you can use system_fopenRO to open a new file buffer structure using filebuf_open.

> ##### Syntax

> SYS_FILE system_fopenRO(char *path);

> ##### Returns

> The system-independent file descriptor (SYS_FILE) if the open succeeded or 0 if the open failed

> ##### Parameters

> char *path is the file name.

> ##### See also

> system_errmsg, system_fopenRW, system_fopenWA, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_fopenRW

> The system_fopenRW function opens the file identified by path in read-write mode and returns a valid file descriptor. If the file already exists, system_fopenRW does not truncate it. Use this function to open files that will be read from and written to by your program.

> ##### Syntax

> SYS_FILE system_fopenRW(char *path);

> ##### Returns

> The system-independent file descriptor (SYS_FILE) if the open succeeded or 0 if the open failed.

> ##### Parameters

> char *path is the file name.

> ##### Example

> SYS_FILE fd;
> fd = system_fopenRO(pathname);
> if (fd == SYS_ERROR_FD)
> break;

> ##### See also

> system_errmsg, system_fopenRO, system_fopenWA, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_fopenWA

> The system_fopenWA function opens the file identified by path in write-append mode and returns a valid file descriptor. Use this function to open those files that your program will append data to.

> ##### Syntax

> SYS_FILE system_fopenWA(char *path);

> ##### Returns

> The system-independent file descriptor (SYS_FILE) if the open succeeded or 0 if the open failed.

> ##### Parameters

> char *path is the file name.

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_fread

> The system_fread function reads a specified number of bytes from a specified file into a specified buffer. It returns the number of bytes read. Before system_fread can be used, you must open the file using any of the system_fopen functions, except system_fopenWA.

> ##### Syntax

> int system_fread(SYS_FILE fd, char *buf, int sz);

> ##### Returns

> The number of bytes read, which may be less than the requested size if an error occurred or the end of the file was reached before that number of characters were obtained.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> char *buf is the buffer to receive the bytes.

> int sz is the number of bytes to read.

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_lseek, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_fwrite

> The system_fwrite function writes a specified number of bytes from a specified buffer into a specified file.

> Before system_fwrite can be used, you must open the file using any of the system_fopen functions, except system_fopenRO.

> ##### Syntax

> int system_fwrite(SYS_FILE fd, char *buf, int sz);

> ##### Returns

> The constant IO_OKAY if the write succeeded or the constant IO_ERROR if the write failed.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> char *buf is the buffer containing the bytes to be written.

> int sz is the number of bytes to write to the file.

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_lseek, system_fread, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_fwrite_atomic

> The system_fwrite_atomic function writes a specified number of bytes from a specified buffer into a specified file. The function also locks the file prior to performing the write, and then unlocks it when done, thereby avoiding interference between simultaneous write actions. Before system_fwrite_atomic can be used, you must open the file using any of the system_fopen functions, except system_fopenRO.

> ##### Syntax

> int system_fwrite_atomic(SYS_FILE fd, char *buf, int sz);

> ##### Returns

> The constant IO_OKAY if the write/lock succeeded or the constant IO_ERROR if the write/lock failed.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> char *buf is the buffer containing the bytes to be written.

> int sz is the number of bytes to write to the file.

> ##### Example

> SYS_FILE logfd;

> char *logmsg = "An error occurred.";
> system_fwrite_atomic(logfd, logmsg, strlen(logmsg));

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_lseek, system_fread, system_fwrite, system_flock, system_ulock, system_fclose

> ### system_gmtime

> The system_gmtime function is a thread-safe version of the standard gmtime function. It returns the current time adjusted to Greenwich Mean Time.

> ##### Syntax

> struct tm *system_gmtime(const time_t *tp, const struct tm *res);

> ##### Returns

> A pointer to a calendar time (tm) structure containing the GMT time. Depending on your system, the pointer may point to the data item represented by the second parameter, or it may point to a statically-allocated item. For portability, do not assume either situation.

> ##### Parameters

> time_t *tp is an arithmetic time.

> tm *res is a pointer to a calendar time (tm) structure.

> ##### Example

> time_t tp;
> struct tm res, *resp;
> tp = time(NULL);
> resp = system_gmtime(&tp, &res);

> ##### See also

> system_localtime, util_strftime

> ### system_localtime

> The system_localtime function is a thread-safe version of the standard localtime function. It returns the current time in the local time zone.

> ##### Syntax

> struct tm *system_localtime(const time_t *tp, const struct tm *res);

> ##### Returns

> A pointer to a calendar time (tm) structure containing the local time. Depending on your system, the pointer may point to the data item represented by the second parameter, or it may point to a statically-allocated item. For portability, do not assume either situation.

> ##### Parameters

> time_t *tp is an arithmetic time.

> tm *res is a pointer to a calendar time (tm) structure.

> ##### See also

> system_gmtime, util_strftime

> ### system_lseek

> The system_lseek function sets the file position of a file. This affects where data from system_fread or system_fwrite is read or written.

> ##### Syntax

> int system_lseek(SYS_FILE fd, int offset, int whence);

> ##### Returns

> the offset, in bytes, of the new position from the beginning of the file if the operation succeeded or -1 if the operation failed.

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> int offset is a number of bytes relative to whence. It may be negative.

> int whence is a one of the following constants:

> SEEK_SET, from the beginning of the file.

> SEEK_CUR, from the current file position.

> SEEK_END, from the end of the file.

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose

> ### system_rename

> The system_rename function renames a file. It may not work on directories if the old and new directories are on different file systems.

> ##### Syntax

> int system_rename(char *old, char *new);

> ##### Returns

> 0 if the operation succeeded or -1 if the operation failed.

> ##### Parameters

> char *old is the old name of the file.

> char *new is the new name for the file:

> ### system_ulock

> The system_ulock function unlocks the specified file that has been locked by the function system_lock. For more information about locking, see system_flock.

> ##### Syntax

> int system_ulock(SYS_FILE fd);

> ##### Returns

> The constant IO_OKAY if the operation succeeded or the constant IO_ERROR if the operation failed

> ##### Parameters

> SYS_FILE fd is the platform-independent file descriptor.

> ##### See also

> system_errmsg, system_fopenRO, system_fopenRW, system_fopenWA, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_fclose

> ### systhread_attach

> The systhread_attach function makes an existing thread into a platform-independent thread.

> ##### Syntax

> SYS_THREAD systhread_attach(void);

> ##### Returns

> A SYS_THREAD pointer to the platform-independent thread.

> ##### Parameters

> none.

> ##### See also

> systhread_current, systhread_getdata, systhread_init, systhread_newkey, systhread_setdata, systhread_sleep, systhread_start, systhread_timerset

> ### systhread_current

> The systhread_current function returns a pointer to the current thread.

> ##### Syntax

> SYS_THREAD systhread_current(void);

> ##### Returns

> A SYS_THREAD pointer to the current thread

> ##### Parameters

> none.

> ##### See also

> systhread_getdata, systhread_newkey, systhread_setdata, systhread_sleep, systhread_start, systhread_timerset

> ### systhread_getdata

> The systhread_getdata function gets data that is associated with a specified key in the current thread.

> ##### Syntax

> void *systhread_getdata(int key);

> ##### Returns

> A pointer to the data that was earlier used with the systhread_setkey function from the current thread, using the same value of key if the call succeeds. Returns NULL if the call did not succeed, for example if the systhread_setkey function was never called with the specified key during this session

> ##### Parameters

> int key is the value associated with the stored data by a systhread_setdata function. Keys are assigned by the systhread_newkey function.

> ##### See also

> systhread_current, systhread_newkey, systhread_setdata, systhread_sleep, systhread_start, systhread_timerset

> ### systhread_newkey

> The systhread_newkey function allocates a new integer key (identifier) for thread-private data. Use this key to identify a variable that you want to localize to the current thread; then use the systhread_setdata function to associate a value with the key.

> ##### Syntax

> int systhread_newkey(void);

> ##### Returns

> An integer key.

> ##### Parameters

> none.

> ##### See also

> systhread_current, systhread_getdata, systhread_setdata, systhread_sleep, systhread_start, systhread_timerset

> ### systhread_setdata

> The systhread_setdata function associates data with a specified key number for the current thread. Keys are assigned by the systhread_newkey function.

> ##### Syntax

> void systhread_setdata(int key, void *data);

> ##### Returns

> void

> ##### Parameters

> int key is the priority of the thread.

> void *data is the pointer to the string of data to be associated with the value of key.

> ##### See also

> systhread_current, systhread_getdata, systhread_newkey, systhread_sleep, systhread_start, systhread_timerset

> ### systhread_sleep

> The systhread_sleep function puts the calling thread to sleep for a given time.

> ##### Syntax

> void systhread_sleep(int milliseconds);

> ##### Returns

> void

> ##### Parameters

> int milliseconds is the number of milliseconds the thread is to sleep.

> ##### See also

> systhread_current, systhread_getdata, systhread_newkey, systhread_setdata, systhread_start, systhread_timerset

> ### systhread_start

> The systhread_start function creates a thread with the given priority, allocates a stack of a specified number of bytes, and calls a specified function with a specified argument.

> ##### Syntax

> SYS_THREAD systhread_start(int prio, int stksz,
> void (*fn)(void *), void *arg);

> ##### Returns

> A new SYS_THREAD pointer if the call succeeded or the constant SYS_THREAD_ERROR if the call did not succeed.

> ##### Parameters

> int prio is the priority of the thread. Priorities are system-dependent.

> int stksz is the stack size in bytes. If stksz is zero, the function allocates a default size.

> void (*fn)(void *) is the function to call.

> void *arg is the argument for the fn function.

> ##### See also

> systhread_current, systhread_getdata, systhread_newkey, systhread_setdata, systhread_sleep, systhread_timerset

> ### systhread_timerset

> The systhread_timerset function starts or resets the interrupt timer interval for a thread system.

> Because most systems don’t allow the timer interval to be changed, this should be considered a suggestion, rather than a command.

> ##### Syntax

> void systhread_timerset(int usec);

> ##### Returns

> void

> ##### Parameters

> int usec is the time, in microseconds

> ##### See also

> systhread_current, systhread_getdata, systhread_newkey, systhread_setdata, systhread_sleep,systhread_start

> ##

> U

> ### util_can_exec

> ##### UNIX only

> The util_can_exec function checks that a specified file can be executed, returning either a 1 (executable) or a 0. The function checks to see if the file can be executed by the user with the given user and group ID.

> Use this function before executing a program using the exec system call.

> ##### Syntax

> int util_can_exec(struct stat *finfo, uid_t uid, gid_t gid);

> ##### Returns

> 1 if the file is executable or 0 if the file is not executable.

> ##### Parameters

> stat *finfo is the stat structure associated with a file.

> uid_t uid is the UNIX user id.

> gid_t gid is the UNIX group id. Together with uid, this determines the permissions of the UNIX user.

> ##### See also

> util_env_create, util_getline, util_hostname

> ### util_chdir2path

> The util_chdir2path function changes the current directory to a specified directory, where you will access a file.

> Use util_chdir2path when you want to make file access a little quicker, because you do not need to use a full paths.

> ##### Syntax

> int util_chdir2path(char *path);

> ##### Returns

> 0 if the directory was changed or -1 if the directory could not be changed.

> ##### Parameters

> char *path is the name of a directory.

> The parameter must be a writable string because it isn’t permanently modified.

> ### util_cookie_find

> The util_cookie_find function finds a specific cookie in a cookie string and returns its value.

> ##### Syntax

> char *util_cookie_find(char *cookie, char *name);

> ##### Returns

> If successful, returns a pointer to the NULL-terminated value of the cookie. Otherwise, returns NULL. This function modifies the cookie string parameter by null-terminating the name and value.

> ##### Parameters

> char *cookie is the value of the Cookie: request header.

> char *name is the name of the cookie whose value is to be retrieved.

> ### util_env_find

> The util_env_find function locates the string denoted by a name in a specified environment and returns the associated value. Use this function to find an entry in an environment.

> ##### Syntax

> char *util_env_find(char **env, char *name);

> ##### Returns

> The value of the environment variable if it is found or NULL if the string was not found.

> ##### Parameters

> char **env is the environment.

> char *name is the name of an environment variable in env.

> ##### See also

> util_env_replace, util_env_str, util_env_free, util_env_create

> ### util_env_free

> The util_env_free function frees a specified environment. Use this function to deallocate an environment you created using the function util_env_create.

> ##### Syntax

> void util_env_free(char **env);

> ##### Returns

> void

> ##### Parameters

> char **env is the environment to be freed.

> ##### See also

> util_env_replace, util_env_str, util_env_find, util_env_create

> ### util_env_replace

> The util_env_replace function replaces the occurrence of the variable denoted by a name in a specified environment with a specified value. Use this function to change the value of a setting in an environment.

> ##### Syntax

> void util_env_replace(char **env, char *name, char *value);

> ##### Returns

> void

> ##### Parameters

> char **env is the environment.

> char *name is the name of a name-value pair.

> char *value is the new value to be stored.

> ##### See also

> util_env_str, util_env_free, util_env_find, util_env_create

> ### util_env_str

> The util_env_str function creates an environment entry and returns it. This function does not check for non alphanumeric symbols in the name (such as the equal sign “=”). You can use this function to create a new environment entry.

> ##### Syntax

> char *util_env_str(char *name, char *value);

> ##### Returns

> A newly-allocated string containing the name-value pair

> ##### Parameters

> char *name is the name of a name-value pair.

> char *value is the new value to be stored.

> ##### See also

> util_env_replace, util_env_free, util_env_find, util_env_create

> ### util_getline

> The util_getline function scans the specified file buffer to find a line-feed or carriage-return/line-feed terminated string. The string is copied into the specified buffer, and NULL-terminates it. The function returns a value that indicates whether the operation stored a string in the buffer, encountered an error, or reached the end of the file.

> Use this function to scan lines out of a text file, such as a configuration file.

> ##### Syntax

> int util_getline(filebuf *buf, int lineno, int maxlen, char *line);

> ##### Returns

> 0 if successful. line contains the string.

> 1 if the end of file was reached. line contains the string.

> -1 if an error occurred. line contains a description of the error.

> ##### Parameters

> filebuf *buf is the file buffer to be scanned.

> int lineno is used to include the line number in the error message when an error occurs. The caller is responsible for making sure the line number is accurate.

> int maxlen is the maximum number of characters that can be written into l.

> char *l is the buffer in which to store the string. The user is responsible for allocating and deallocating line.

> ##### See also

> util_can_exec, util_env_create, util_hostname

> ### util_hostname

> The util_hostname function retrieves the local host name and returns it as a string. If the function cannot find a fully-qualified domain name, it returns NULL. You may reallocate or free this string. Use this function to determine the name of the system you are on.

> ##### Syntax

> char *util_hostname(void);

> ##### Returns

> If a fully-qualified domain name was found, returns a string containing that name otherwise returns NULL if the fully-qualified domain name was not found.

> ##### Parameters

> none.

> ### util_is_mozilla

> The util_is_mozilla function checks whether a specified user-agent header string is a browser of at least a specified revision level, returning a 1 if it is and 0 otherwise. It uses strings to specify the revision level to avoid ambiguities like 1.56 > 1.5.

> ##### Syntax

> int util_is_mozilla(char *ua, char *major, char *minor);

> ##### Returns

> 1 if the user-agent is a Netscape browser or 0 if the user-agent is not a Netscape browser.

> ##### Parameters

> char *ua is the user-agent string from the request headers.

> char *major is the major release number (to the left of the decimal point).

> char *minor is the minor release number (to the right of the decimal point).

> ##### See also

> util_is_url, util_later_than

> ### util_is_url

> The util_is_url function checks whether a string is a URL, returning 1 if it is and 0 otherwise. The string is a URL if it begins with alphabetic characters followed by a colon.

> ##### Syntax

> int util_is_url(char *url);

> ##### Returns

> 1 if the string specified by url is a URL or 0 if the string specified by url is not a URL.

> ##### Parameters

> char *url is the string to be examined.

> ##### See also

> util_is_mozilla, util_later_than

> ### util_itoa

> The util_itoa function converts a specified integer to a string, and returns the length of the string. Use this function to create a textual representation of a number.

> ##### Syntax

> int util_itoa(int i, char *a);

> ##### Returns

> The length of the string created

> ##### Parameters

> int i is the integer to be converted.

> char *a is the ASCII string that represents the value. The user is responsible for the allocation and deallocation of a, and it should be at least 32 bytes long.

> ### util_later_than

> The util_later_than function compares the date specified in a time structure against a date specified in a string. If the date in the string is later than or equal to the one in the time structure, the function returns 1. Use this function to handle RFC 822, RFC 850, and ctime formats.

> ##### Syntax

> int util_later_than(struct tm *lms, char *ims);

> ##### Returns

> 1 if the date represented by ims is the same as or later than that represented by the lms or 0 if the date represented by ims is earlier than that represented by the lms.

> ##### Parameters

> tm *lms is the time structure containing a date.

> char *ims is the string containing a date.

> ##### See also

> util_strftime

> ### util_sh_escape

> The util_sh_escape function parses a specified string and places a backslash (\) in front of any shell-special characters, returning the resultant string. Use this function to ensure that strings from clients won’t cause a shell to do anything unexpected.

> The shell-special characters are the space plus the following characters:

> &;`'"|*?~<>^()[]{}$\#!

> ##### Syntax

> char *util_sh_escape(char *s);

> ##### Returns

> A newly allocated string

> ##### Parameters

> char *s is the string to be parsed.

> ##### See also

> util_uri_escape

> ### util_snprintf

> The util_snprintf function formats a specified string, using a specified format, into a specified buffer using the printf-style syntax and performs bounds checking. It returns the number of characters in the formatted buffer.

> For more information, see the documentation on the printf function for the run-time library of your compiler.

> ##### Syntax

> int util_snprintf(char *s, int n, char *fmt, ...);

> ##### Returns

> The number of characters formatted into the buffer.

> ##### Parameters

> char *s is the buffer to receive the formatted string.

> int n is the maximum number of bytes allowed to be copied.

> char *fmt is the format string. The function handles only %d and %s strings; it does not handle any width or precision strings.

> ... represents a sequence of parameters for the printf function.

> ##### See also

> util_sprintf, util_vsnprintf, util_vsprintf

> ### util_sprintf

> The util_sprintf function formats a specified string, using a specified format, into a specified buffer using the printf-style syntax without bounds checking. It returns the number of characters in the formatted buffer.

> Because util_sprintf doesn’t perform bounds checking, use this function only if you are certain that the string fits the buffer. Otherwise, use the function util_snprintf. For more information, see the documentation on the printf function for the run-time library of your compiler.

> ##### Syntax

> int util_sprintf(char *s, char *fmt, ...);

> ##### Returns

> The number of characters formatted into the buffer.

> ##### Parameters

> char *s is the buffer to receive the formatted string.

> char *fmt is the format string. The function handles only %d and %s strings; it does not handle any width or precision strings.

> ... represents a sequence of parameters for the printf function.

> ##### Example

> char *logmsg;
> int len;

> logmsg = (char *) MALLOC(256);
> len = util_sprintf(logmsg, "%s %s %s\n", ip, method, uri);

> ##### See also

> util_snprintf, util_vsnprintf, util_vsprintf

> ### util_strcasecmp

> The util_strcasecmp function performs a comparison of two alpha-numeric strings and returns a -1, 0, or 1 to signal which is larger or that they are identical.

> The comparison is not case-sensitive.

> ##### Syntax

> int util_strcasecmp(const char *s1, const char *s2);

> ##### Returns

> 1 if s1 is greater than s2.

> 0 if s1 is equal to s2.

> -1 if s1 is less than s2.

> ##### Parameters

> char *s1 is the first string.

> char *s2 is the second string.

> ##### See also

> util_strncasecmp

> ### util_strftime

> The util_strftime function translates a tm structure, which is a structure describing a system time, into a textual representation. It is a thread-safe version of the standard strftime function

> ##### Syntax

> int util_strftime(char *s, const char *format, const struct tm *t);

> ##### Returns

> The number of characters placed into s, not counting the terminating NULL character.

> ##### Parameters

> char *s is the string buffer to put the text into. There is no bounds checking, so you must make sure that your buffer is large enough for the text of the date.

> const char *format is a format string, a bit like a printf string in that it consists of text with certain %x substrings. You may use the constant HTTP_DATE_FMT to create date strings in the standard internet format. For more information, see the documentation on the printf function for the run-time library of your compiler. Refer to Appendix C, “Time Formats,” for details on time formats.

> const struct tm *t is a pointer to a calendar time (tm) struct, usually created by the function system_localtime or system_gmtime.

> ##### See also

> system_localtime, system_gmtime

> ### util_strncasecmp

> The util_strncasecmp function performs a comparison of the first n characters in the alpha-numeric strings and returns a -1, 0, or 1 to signal which is larger or that they are identical.

> The function’s comparison is not case-sensitive.

> ##### Syntax

> int util_strncasecmp(const char *s1, const char *s2, int n);

> ##### Returns

> 1 if s1 is greater than s2.

> 0 if s1 is equal to s2.

> -1 if s1 is less than s2.

> ##### Parameters

> char *s1 is the first string.

> char *s2 is the second string.

> int n is the number of initial characters to compare.

> ##### See also

> util_strcasecmp

> ### util_uri_escape

> The util_uri_escape function converts any special characters in the URI into the URI format (%XX where XX is the hexadecimal equivalent of the ASCII character), and returns the escaped string. The special characters are %?#:+&*"<>, space, carriage-return, and line-feed.

> Use util_uri_escape before sending a URI back to the client.

> ##### Syntax

> char *util_uri_escape(char *d, char *s);

> ##### Returns

> The string (possibly newly allocated) with escaped characters replaced.

> ##### Parameters

> char *d is a string. If d is not NULL, the function copies the formatted string into d and returns it. If d is NULL, the function allocates a properly-sized string and copies the formatted special characters into the new string, then returns it.

> The util_uri_escape function does not check bounds for the parameter d. Therefore, if d is not NULL, it should be at least three times as large as the string s.

> char *s is the string containing the original unescaped URI.

> ##### See also

> util_uri_is_evil, util_uri_parse, util_uri_unescape

> ### util_uri_is_evil

> The util_uri_is_evil function checks a specified URI for insecure path characters. Insecure path characters include //, /./, /../ and/., /.. at the end of the URI. Use this function to see if a URI requested by the client is insecure.

> ##### Syntax

> int util_uri_is_evil(char *t);

> ##### Returns

> 1 if the URI is insecure or 0 if the URI is OK.

> ##### Parameters

> char *t is the URI to be checked.

> ##### See also

> util_uri_escape, util_uri_parse

> ### util_uri_parse

> The util_uri_parse function converts //, /./, and /*/../ into / in the specified URI (where * is any character other than /). You can use this function to convert a URI’s bad sequences into valid ones. First use the function util_uri_is_evil to determine whether the function has a bad sequence.

> ##### Syntax

> void util_uri_parse(char *uri);

> ##### Returns

> void

> ##### Parameters

> char *uri is the URI to be converted.

> ##### See also

> util_uri_is_evil, util_uri_unescape

> ### util_uri_unescape

> The util_uri_unescape function converts the encoded characters of a URI into their ASCII equivalents. Encoded characters appear as %XX where XX is a hexadecimal equivalent of the character.

> Note | You cannot use an embedded null in a string, because NSAPI functions assume that a null is the end of the string. Therefore, passing unicode-encoded content through an NSAPI plug-in doesn’t work.

> ##### Syntax

> void util_uri_unescape(char *uri);

> ##### Returns

> void

> ##### Parameters

> char *uri is the URI to be converted.

> ##### See also

> util_uri_escape, util_uri_is_evil, util_uri_parse

> ### util_vsnprintf

> The util_vsnprintf function formats a specified string, using a specified format, into a specified buffer using the vprintf-style syntax and performs bounds checking. It returns the number of characters in the formatted buffer.

> For more information, see the documentation on the printf function for the run-time library of your compiler.

> ##### Syntax

> int util_vsnprintf(char *s, int n, register char *fmt, va_list args);

> ##### Returns

> The number of characters formatted into the buffer

> ##### Parameters

> char *s is the buffer to receive the formatted string.

> int n is the maximum number of bytes allowed to be copied.

> register char *fmt is the format string. The function handles only %d and %s strings; it does not handle any width or precision strings.

> va_list args is an STD argument variable obtained from a previous call to va_start.

> ##### See also

> util_sprintf, util_vsprintf

> ### util_vsprintf

> The util_vsprintf function formats a specified string, using a specified format, into a specified buffer using the vprintf-style syntax without bounds checking. It returns the number of characters in the formatted buffer.

> For more information, see the documentation on the printf function for the run-time library of your compiler.

> ##### Syntax

> int util_vsprintf(char *s, register char *fmt, va_list args);

> ##### Returns

> The number of characters formatted into the buffer.

> ##### Parameters

> char *s is the buffer to receive the formatted string.

> register char *fmt is the format string. The function handles only %d and %s strings; it does not handle any width or precision strings.

> va_list args is an STD argument variable obtained from a previous call to va_start.

> ##### See also

> util_snprintf, util_vsnprintf

> ##

> V

> ### vs_alloc_slot

> The vs_alloc_slot function allocates a new slot for storing a pointer to data specific to a certain VirtualServer*. The returned slot number may be used in subsequent vs_set_data and vs_get_data calls. The returned slot number is valid for any VirtualServer*.

> The value of the pointer (which may be returned by a call to vs_set_data) defaults to NULL for every VirtualServer*.

> ##### Syntax

> int vs_alloc_slot(void);

> ##### Returns

> A slot number on success, or -1 on failure.

> ##### See also

> vs_get_data, vs_set_data

> ### vs_get_data

> The vs_get_data function finds the value of a pointer to data for a given VirtualServer* and slot. The slot must be a slot number returned from vs_alloc_slot or vs_set_data.

> ##### Syntax

> void* vs_get_data(const VirtualServer* vs, int slot);

> ##### Returns

> The value of the pointer previously stored via vs_set_data, or NULL on failure.

> ##### Parameters

> const VirtualServer* vs represents the virtual server to query the pointer for.

> int slot is the slot number to retrieve the pointer from.

> ##### See also

> vs_set_data, vs_alloc_slot

> ### vs_get_default_httpd_object

> The vs_get_default_httpd_object function obtains a pointer to the default (or root) httpd_object from the virtual server's httpd_objset (in the configuration defined by the obj.conf file of the virtual server class). The default object is typically named default. Plug-ins may only modify the httpd_object at VSInitFunc time (see vs_register_cb for an explanation of VSInitFunc time).

> Do not FREE the returned object.

> ##### Syntax

> httpd_object* vs_get_default_httpd_object(VirtualServer* vs);

> ##### Returns

> A pointer the default httpd_object, or NULL on failure. Do not FREE this object.

> ##### Parameters

> VirtualServer* vs represents the virtual server for which to find the default object.

> ##### See also

> vs_get_httpd_objset, vs_register_cb

> ### vs_get_doc_root

> The vs_get_doc_root function finds the document root for a virtual server. The returned string is the full operating system path to the document root.

> The caller should FREE the returned string when done with it.

> ##### Syntax

> char* vs_get_doc_root(const VirtualServer* vs);

> ##### Returns

> A pointer to a string representing the full operating system path to the document root. It is the caller's responsibility to FREE this string.

> ##### Parameters

> const VirtualServer* vs represents the virtual server for which to find the document root.

> ### vs_get_httpd_objset

> The vs_get_httpd_objset function obtains a pointer to the httpd_objset (the configuration defined by the obj.conf file of the virtual server class) for a given virtual server. Plug-ins may only modify the httpd_objset at VSInitFunc time (see vs_register_cb for an explanation of VSInitFunc time).

> Do not FREE the returned objset.

> ##### Syntax

> httpd_objset* vs_get_httpd_objset(VirtualServer* vs);

> ##### Returns

> A pointer to the httpd_objset, or NULL on failure. Do not FREE this objset.

> ##### Parameters

> VirtualServer* vs represents the virtual server for which to find the objset.

> ##### See also

> vs_get_default_httpd_object, vs_register_cb

> ### vs_get_id

> The vs_get_id function finds the ID of a VirtualServer*.

> The ID of a virtual server is a unique null-terminated string that remains constant across configurations. Note that while IDs remain constant across configurations, the value of VirtualServer* pointers do not.

> Do not FREE the virtual server ID string. If called during request processing, the string will remain valid for the duration of the current request. If called during VSInitFunc processing, the string will remain valid until after the corresponding VSDestroyFunc function has returned (see vs_register_cb).

> To retrieve a VirtualServer* that is valid only for the current request, use request_get_vs.

> ##### Syntax

> const char* vs_get_id(const VirtualServer* vs);

> ##### Returns

> A pointer to a string representing the virtual server ID. Do not FREE this string.

> ##### Parameters

> const VirtualServer* vs represents the virtual server of interest.

> ##### See also

> vs_register_cb, request_get_vs

> ### vs_get_mime_type

> The vs_get_mime_type function determines the MIME type that would be returned in the Content-type: header for the given URI.

> The caller should FREE the returned string when done with it.

> ##### Syntax

> char* vs_get_mime_type(const VirtualServer* vs, const char* uri);

> ##### Returns

> A pointer to a string representing the MIME type. It is the caller's responsibility to FREE this string.

> ##### Parameters

> const VirtualServer* vs represents the virtual server of interest.

> const char* uri is the URI whose MIME type is of interest.

> ### vs_lookup_config_var

> The vs_lookup_config_var function finds the value of a configuration variable for a given virtual server.

> Do not FREE the returned string.

> ##### Syntax

> const char* vs_lookup_config_var(const VirtualServer* vs, const char* name);

> ##### Returns

> A pointer to a string representing the value of variable name on success, or NULL if variable name was not found. Do not FREE this string.

> ##### Parameters

> const VirtualServer* vs represents the virtual server of interest.

> const char* name is the name of the configuration variable.

> ### vs_register_cb

> The vs_register_cb function allows a plug-in to register functions that will receive notifications of virtual server initialization and destruction events. The vs_register_cb function would typically be called from an Init SAF in init.conf.

> When a new configuration is loaded, all registered VSInitFunc (virtual server initialization) callbacks are called for each of the virtual servers before any requests are served from the new configuration. VSInitFunc callbacks are called in the same order they were registered; that is, the first callback registered is the first called.

> When the last request has been served from an old configuration, all registered VSDestroyFunc (virtual server destruction) callbacks are called for each of the virtual servers before any virtual servers are destroyed. VSDestroyFunc callbacks are called in reverse order; that is, the first callback registered is the last called.

> Either initfn or destroyfn may be NULL if the caller is not interested in callbacks for initialization or destruction, respectively.

> ##### Syntax

> int vs_register_cb(VSInitFunc* initfn, VSDestroyFunc* destroyfn);

> ##### Returns

> The constant REQ_PROCEED if the operation succeeded.

> The constant REQ_ABORTED if the operation failed.

> ##### Parameters

> VSInitFunc* initfn is a pointer to the function to call at virtual server initialization time, or NULL if the caller is not interested in virtual server initialization events.

> VSDestroyFunc* destroyfn is a pointer to the function to call at virtual server destruction time, or NULL if the caller is not interested in virtual server destruction events.

> ### vs_set_data

> The vs_set_data function sets the value of a pointer to data for a given virtual server and slot. The *slot must be -1 or a slot number returned from vs_alloc_slot. If *slot is -1, vs_set_data calls vs_alloc_slot implicitly and returns the new slot number in *slot.

> Note that the stored pointer is maintained on a per-VirtualServer* basis, not a per-ID basis. Distinct VirtualServer*s from different configurations may exist simultaneously with the same virtual server IDs. However, since these are distinct VirtualServer*s, they each have their own VirtualServer*-specific data. As a result, vs_set_data should generally not be called outside of VSInitFunc processing (see vs_register_cb for an explanation of VSInitFunc processing).

> ##### Syntax

> void* vs_set_data(const VirtualServer* vs, int* slot, void* data);

> ##### Returns

> Data on success, NULL on failure.

> ##### Parameters

> const VirtualServer* vs represents the virtual server to set the pointer for.

> int* slot is the slot number to store the pointer at.

> void* data is the pointer to store.

> ##### See also

> vs_get_data, vs_alloc_slot, vs_register_cb

> ### vs_translate_uri

> The vs_translate_uri function translates a URI as though it were part of a request for a specific virtual server. The returned string is the full operating system path.

> The caller should FREE the returned string when done with it.

> ##### Syntax

> char* vs_translate_uri(const VirtualServer* vs, const char* uri);

> ##### Returns

> A pointer to a string representing the full operating system path for the given URI. It is the caller's responsibility to FREE this string.

> ##### Parameters

> const VirtualServer* vs represents the virtual server for which to translate the URI.

> const char* uri is the URI to translate to an operating system path.

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> Copyright 2004 Sun Microsystems, Inc. All rights reserved.