cc [ flag ... ] file ... –lgen [ library ... ] #include <libgen.h> char *pathfind(const char *path, const char *name, const char *mode);
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]:
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.
To find the ls command using the PATH environment variable:
pathfind (getenv ("PATH"), "ls", "rx")
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).
See attributes(5) for descriptions of the following attributes:
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.