PATHFIND(3GEN) String Pattern-Matching Library Functions PATHFIND(3GEN)


NAME


pathfind - search for named file in named directories

SYNOPSIS


cc [ flag ... ] file ... -lgen [ library ... ]
#include <libgen.h>

char *pathfind(const char *path, const char *name, const char *mode);


DESCRIPTION


The pathfind() function searches the directories named in path for the
file name. The directories named in path are separated by colons (:). The
mode argument is a string of option letters chosen from the set
[rwxfbcdpugks]:


+-------+-------------------+
|Letter | Meaning |
+-------+-------------------+
|r | readable |
+-------+-------------------+
|w | writable |
+-------+-------------------+
|x | executable |
+-------+-------------------+
|f | normal file |
+-------+-------------------+
|b | block special |
+-------+-------------------+
|c | character special |
+-------+-------------------+
|d | directory |
+-------+-------------------+
|p | FIFO (pipe) |
+-------+-------------------+
|u | set user ID bit |
+-------+-------------------+
|g | set group ID bit |
+-------+-------------------+
|k | sticky bit |
+-------+-------------------+
|s | size non-zero |
+-------+-------------------+


Options read, write, and execute are checked relative to the real (not
the effective) user ID and group ID of the current process.


If name begins with a slash, it is treated as an absolute path name, and
path is ignored.


An empty path member is treated as the current directory. A slash (/)
character is not prepended at the occurrence of the first match; rather,
the unadorned name is returned.

EXAMPLES


Example 1: Example of finding the ls command using the PATH environment


variable.


To find the ls command using the PATH environment variable:


pathfind (getenv ("PATH"), "ls", "rx")


RETURN VALUES


The pathfind() function returns a (char *) value containing static,
thread-specific data that will be overwritten upon the next call from the
same thread.


If the file name with all characteristics specified by mode is found in
any of the directories specified by path, then pathfind() returns a
pointer to a string containing the member of path, followed by a slash
character (/), followed by name.


If no match is found, pathname() returns a null pointer, ((char *) 0).

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | MT-Safe |
+---------------+-----------------+

SEE ALSO


sh(1), test(1), access(2), mknod(2), stat(2), getenv(3C), attributes(5)

NOTES


The string pointed to by the returned pointer is stored in an area that
is reused on subsequent calls to pathfind(). The string should not be
deallocated by the caller.


When compiling multithreaded applications, the _REENTRANT flag must be
defined on the compile line. This flag should only be used in
multithreadedapplications.


March 10, 1999 PATHFIND(3GEN)