basename(3p) — Linux manual page

PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

BASENAME(3P)            POSIX Programmer's Manual           BASENAME(3P)

PROLOG         top

       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         top

       basename — return the last component of a pathname

SYNOPSIS         top

       #include <libgen.h>

       char *basename(char *path);

DESCRIPTION         top

       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         top

       The basename() function shall return a pointer to the final
       component of path.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

   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
       .TS
┌──────────────┬───────────┬────────────┬──────────────┬─────────────────┬───────────┐
│  basename()  │           │            │   basename   Output      Output   │
│and dirname() String   String   and dirname  Written by    Written by │
│Functions pathReturned byReturned by Utilities   basename     dirname   │
│   Argument   basename() dirname()  string OperandUtility     Utility   │
├──────────────┼───────────┼────────────┼──────────────┼─────────────────┼───────────┤
│"usr"         │"usr"      │"."         │usr           │usr              │.          │
├──────────────┼───────────┼────────────┼──────────────┼─────────────────┼───────────┤
│"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 │
│test"         │           │            │test          │                 │           │
└───────.─S─H──"─A─P─P┴L─I─C─A─T─I─O─N──U─S─A┴G─E─"──%─%─%─S─H─%─%─%─┴N─o─n─e─.──────────┴─────────────────┴───────────┘

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       dirname(3p)

       The Base Definitions volume of POSIX.1‐2017, libgen.h(0p)

       The Shell and Utilities volume of POSIX.1‐2017, basename(1p)

COPYRIGHT         top

       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 .

IEEE/The Open Group               2017                      BASENAME(3P)

Pages that refer to this page: libgen.h(0p)basename(1p)dirname(1p)dirname(3p)