S

sendfile

The sendfile filter method is called when the contents of a file are to be sent. Filters that modify or consume outgoing data may choose to implement the sendfile filter method.

If a filter implements the write filter method but not the sendfile filter method, the server will automatically translate net_sendfile calls to net_write calls. As a result, filters interested in the outgoing data stream do not need to implement the sendfile filter method. However, for performance reasons, it is beneficial for filters that implement the write filter method to also implement the sendfile filter method.

Syntax

int sendfile(FilterLayer *layer, const sendfiledata *data);

Returns

The number of bytes consumed, which may be less than the requested amount if an error occurred.

Parameters

FilterLayer *layer is the filter layer the filter is installed in.

const sendfiledata *sfd identifies the data to send.

Example

int myfilter_sendfile(FilterLayer *layer, const sendfiledata *sfd)
{
    return net_sendfile(layer->lower, sfd);
}

See Also

net_sendfile

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.

This function works only if the DNS directive is enabled in the magnus.conf file. For more information, seeChapter 2, SAFs in the magnus.conf File

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.

This function works only if the DNS directive is enabled in the magnus.conf file. For more information, seeChapter 2, SAFs in the magnus.conf File

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 *.netscape.com and you want to make sure that a string matches it, such as foo.netscape.com.

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 *.netscape.com and you want to make sure that a string matches it, such as foo.netscape.com.

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/netscape/*";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 prevalidated 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 such as *.netscape.com, and you want to make sure that a string matches it, such as foo.netscape.com.

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 prevalidated 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.

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_CALLOC, 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 to use 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 to which your program will append data.

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 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

system_unix2local

The system_unix2local function converts a specified UNIX-style path name to a local file system path name. Use this function when you have a file name in the UNIX format (such as one containing forward slashes), and you need to access a file on another system such as Windows. You can use system_unix2local to convert the UNIX file name into the format that Windows accepts. In the UNIX environment this function does nothing, but may be called for portability.

Syntax

char *system_unix2local(char *path, char *lp);

Returns

A pointer to the local file system path string.

Parameters

char *path is the UNIX-style path name to be converted.

char *lp is the local path name.

You must allocate the parameter lp, and it must contain enough space to hold the local path name.

See Also

system_fclose, system_flock, system_fopenRO, system_fopenRW, system_fopenWA, system_fwrite

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 (0), 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.

Most of the systems do not 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