basename - Man Page

return the last component of a pathname


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.


#include <libgen.h>

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 '/' 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.


No errors are defined.

The following sections are informative.


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

and dirname()StringStringand dirnameWritten byWritten by
Functions pathReturned byReturned byUtilitiesbasenamedirname
Argumentbasename()dirname()string OperandUtilityUtility
"""."".""". or empty string.
"//""/" or "//""/" or "//"/// or /// or //

Application Usage




Future Directions


See Also


The Base Definitions volume of POSIX.1-2017, <libgen.h>

The Shell and Utilities volume of POSIX.1-2017, basename

Referenced By

basename(1p), dirname(1p), dirname(3p), libgen.h(0p).

2017 IEEE/The Open Group POSIX Programmer's Manual