basename3p
Return the last component of a pathname
Usage
#include <libgen.h>
char *basename(char *path);
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.
Overview
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
| basename() | basename | Output | Output | ||
| and dirname() | String | String | and dirname | Written by | Written by |
| Functions path | Returned by | Returned by | Utilities | basename | dirname |
| Argument | basename() | dirname() | string Operand | Utility | Utility |
| "usr" | "usr" | "." | usr | usr | |
| "usr/" | "usr" | "." | usr/ | usr | |
| "" | "." | "." | "" | ||
| "/" | "/" | "/" | / | / | / |
| "//" | "/" 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 |
| test" | test |
Application usage
None.
Rationale
None.
Future directions
None.