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.
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 basename() function need not be thread-safe.
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 basename()
In the following table, the input string is the value pointed to by
path, and the output string is the return value of the basename()
│ Input String │ Output String │
│"/usr/lib" │ "lib" │
│"/usr/" │ "usr" │
│"/" │ "/" │
│"///" │ "/" │
│"//usr//lib//" │ "lib" │
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/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
IEEE/The Open Group 2013 BASENAME(3P)