BASENAME
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
basename
--- return the last component of a pathname
SYNOPSIS
#include <libgen.h>
char *basename(char *path);
DESCRIPTION
The
basename()
function shall take the pathname pointed to by
path
and return a pointer to the final component of the pathname, deleting
any trailing
'/'
characters.
If the string pointed to by
path
consists entirely of the
'/'
character,
basename()
shall return a pointer to the string
"/".
If the string pointed to by
path
is exactly
"//",
it is implementation-defined whether
'/'
or
"//"
is returned.
If
path
is a null pointer or points to an empty string,
basename()
shall return a pointer to the string
".".
The
basename()
function may modify the string pointed to by
path,
and may return a pointer to internal storage. The returned pointer
might be invalidated or the storage might be overwritten by a
subsequent call to
basename().
The returned pointer might also be invalidated if the calling
thread is terminated.
The
basename()
function need not be thread-safe.
RETURN VALUE
The
basename()
function shall return a pointer to the final component of
path.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
Using basename()
The following program fragment returns a pointer to the value
lib,
which is the base name of
/usr/lib.
-
#include <libgen.h>
...
char name[] = "/usr/lib";
char *base;
base = basename(name);
...
Sample Input and Output Strings for the basename() and dirname() Functions and the basename and dirname Utilities
|
| "usr/" | "usr" | "." | usr/ | usr | .
|
|
| "" | "." | "." | "" | . or empty string | .
|
|
| "/" | "/" | "/" | / | / | /
|
|
| "//" | "/" or "//" | "/" or "//" | // | / or // | / or //
|
|
| "///" | "/" | "/" | /// | / | /
|
|
| "/usr/" | "usr" | "/" | /usr/
| usr
| /
|
|
| "/usr/lib" | "lib" | "/usr" | /usr/lib | lib
| /usr
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| "//usr//lib//" | "lib" | "//usr" | //usr//lib// | lib
| //usr
|
|
|
|
|
|
|
|
|
|
|
|
| "/home//dwc// | "test" | "/home//dwc" | /home//dwc// | test
| /home//dwc
|
|
|
|
|
|
|
|
|
|
|
|
|
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
dirname()
The Base Definitions volume of POSIX.1-2017,
<libgen.h>
The Shell and Utilities volume of POSIX.1-2017,
basename
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .