BASENAME(3) BSD Library Functions Manual BASENAME(3)NAME
basename -- extract the base portion of a pathname
SYNOPSIS
#include <libgen.h>
char *
basename(const char *path);
char *
basename_r(const char *path, char *bname);
DESCRIPTION
The basename() function returns the last component from the pathname pointed to by path, deleting any trailing '/' characters. If path con-
sists entirely of '/' characters, a pointer to the string "/" is returned. If path is a null pointer or the empty string, a pointer to the
string "." is returned.
The basename_r() variation accepts a buffer of at least MAXPATHLEN bytes in which to store the resulting component.
IMPLEMENTATION NOTES
The basename() function returns a pointer to internal storage space allocated on the first call that will be overwritten by subsequent calls.
basename_r() is therefore preferred for threaded applications.
RETURN VALUES
On successful completion, basename() and basename_r() return pointers to the last component of path.
If they fail, a null pointer is returned and the global variable errno is set to indicate the error.
ERRORS
The following error codes may be set in errno:
[ENAMETOOLONG] The path component to be returned was larger than MAXPATHLEN.
SEE ALSO basename(1), dirname(1), dirname(3)STANDARDS
The basename() function conforms to X/Open Portability Guide Issue 4, Version 2 (``XPG4.2'').
HISTORY
The basename() function first appeared in OpenBSD 2.2 and FreeBSD 4.2.
AUTHORS
Todd C. Miller
CAVEATS
basename() returns a pointer to internal static storage space that will be overwritten by subsequent calls.
Other vendor implementations of basename() may modify the contents of the string passed to basename(); this should be taken into account when
writing code which calls this function if portability is desired.
BSD March 31, 2010 BSD
Check Out this Related Man Page
BASENAME(3) Linux Programmer's Manual BASENAME(3)NAME
basename, dirname - parse pathname components
SYNOPSIS
#include <libgen.h>
char *dirname(char *path);
char *basename(char *path);
DESCRIPTION
Warning: there are two different functions basename() - see below.
The functions dirname() and basename() break a null-terminated pathname string into directory and filename components. In the usual case,
dirname() returns the string up to, but not including, the final '/', and basename() returns the component following the final '/'. Trail-
ing '/' characters are not counted as part of the pathname.
If path does not contain a slash, dirname() returns the string "." while basename() returns a copy of path. If path is the string "/",
then both dirname() and basename() return the string "/". If path is a NULL pointer or points to an empty string, then both dirname() and
basename() return the string ".".
Concatenating the string returned by dirname(), a "/", and the string returned by basename() yields a complete pathname.
Both dirname() and basename() may modify the contents of path, so it may be desirable to pass a copy when calling one of these functions.
These functions may return pointers to statically allocated memory which may be overwritten by subsequent calls. Alternatively, they may
return a pointer to some part of path, so that the string referred to by path should not be modified or freed until the pointer returned by
the function is no longer required.
The following list of examples (taken from SUSv2) shows the strings returned by dirname() and basename() for different paths:
path dirname basename
/usr/lib /usr lib
/usr/ / usr
usr . usr
/ / /
. . .
.. . ..
RETURN VALUE
Both dirname() and basename() return pointers to null-terminated strings. (Do not pass these pointers to free(3).)
CONFORMING TO
POSIX.1-2001.
NOTES
There are two different versions of basename() - the POSIX version described above, and the GNU version, which one gets after
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <string.h>
The GNU version never modifies its argument, and returns the empty string when path has a trailing slash, and in particular also when it is
"/". There is no GNU version of dirname().
With glibc, one gets the POSIX version of basename() when <libgen.h> is included, and the GNU version otherwise.
BUGS
In the glibc implementation of the POSIX versions of these functions they modify their argument, and segfault when called with a static
string like "/usr/". Before glibc 2.2.1, the glibc version of dirname() did not correctly handle pathnames with trailing '/' characters,
and generated a segfault if given a NULL argument.
EXAMPLE
char *dirc, *basec, *bname, *dname;
char *path = "/etc/passwd";
dirc = strdup(path);
basec = strdup(path);
dname = dirname(dirc);
bname = basename(basec);
printf("dirname=%s, basename=%s
", dname, bname);
SEE ALSO basename(1), dirname(1)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2009-03-30 BASENAME(3)