BASENAME(3P) POSIX Programmer's Manual BASENAME(3P)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.
NAMEbasename — return the last component of a pathname
char *basename(char *path);
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 '/' charac‐
ter, 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
The basename() function need not be thread-safe.
The basename() function shall return a pointer to the final component
No errors are defined.
The following sections are informative.
The following program fragment returns a pointer to the value lib,
which is the base name of /usr/lib.
char *name = "/usr/lib";
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() func‐
│ Input String │ Output String │
│"/usr/lib" │ "lib" │
│"/usr/" │ "usr" │
│"/" │ "/" │
│"///" │ "/" │
│"//usr//lib//" │ "lib" │
The Base Definitions volume of POSIX.1‐2008, <libgen.h>
The Shell and Utilities volume of POSIX.1‐2008, basenameCOPYRIGHT
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 Electri‐
cal 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 .
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IEEE/The Open Group 2013 BASENAME(3P)