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basename(3)
NAME
  basename, dirname, dirname_r - Return the base filename or directory
  portion of a pathname

SYNOPSIS
  #include <libgen.h>

  char *basename(
	  char *path );

  char *dirname(
	  char *path );

  The following function is supported only for backward compatibility:

  #include <string.h>

  int dirname_r
	  char *path,
	  char *buf,
	  int size );

LIBRARY
  Standard C Library (libc)

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  basename(), dirname(): XSH4.2

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  path
      The string from which the base pathname or the directory portion is to
      be extracted.

  buf [Tru64 UNIX]  Specifies a working buffer to hold the directory name
      component.

  size
      [Tru64 UNIX]  Specifies the length of buf.

DESCRIPTION
  The basename() and dirname() functions complement each other. The
  basename() function reads path and returns a pointer to the final component
  of the pathname, deleting any trailing / (slash) characters. If the string
  consists entirely of the / (slash) character, basename() returns a pointer
  to the string / (slash).  If path is a null pointer or points to an empty
  string, basename() returns a pointer to the string . (period).

  [Tru64 UNIX]	In applications that are compiled in an environment that
  excludes the _XOPEN_SOURCE_EXTENDED standard definitions, the basename()
  function returns an empty string if the string consists entirely of the /
  (slash) character. If path is a null pointer, basename() returns a core
  dump. If path points to an empty string, basename() returns an empty
  string.

  The dirname() function reads path and returns a pointer to a new string
  that is a pathname of the parent directory of that file. Trailing / (slash)
  characters in the path are not counted as part of the path. If there is no
  / (slash), if path is a null pointer, or if path points to an empty string,
  the dirname() function returns a pointer to the string . (period).

  [Tru64 UNIX]	In applications that are compiled in an environment that
  excludes the _XOPEN_SOURCE_EXTENDED standard definitions, the dirname()
  function returns a NULL if there is no / (slash), and a core dump if path
  is a null pointer, or if path points to an empty string.

  The dirname_r() function is the reentrant version of the dirname()
  function. It is supported only to maintain backward compatibility with
  versions of the operating system prior to Digital UNIX Version 4.0.

NOTES
  The value returned by the basename() and dirname() functions is a pointer
  to a thread-specific buffer whose contents will be overwritten on
  subsequent calls from the same thread.

  [Tru64 UNIX]	The basename(), dirname(), and dirname_r() functions belong
  to a small set of libc functions that are handled differently when compiled
  in the X/Open UNIX environment. In the X/Open UNIX environment, calls to
  these functions are internally renamed by prepending _E to the function
  name. The renaming is done only when there is an incompatible conflict
  between an existing version of the function and the version that conforms
  to the X/Open UNIX standard. The renaming strategy supports binary
  compatibility by allowing applications to compile in the X/Open UNIX
  environment and also link with site-specific and third-party libraries that
  use the old versions of the same libc interfaces. However, internal
  renaming of the calls affects how these calls are identified during
  debugging sessions. Therefore, when you are debugging a module that
  includes the basename() and/or dirname() or dirname_r() functions and for
  which _XOPEN_SOURCE_EXTENDED has been defined, use _Ebasename to refer to
  the basename() call and _Edirname to refer to the dirname call and
  _Edirname_r to refer to the dirname_r call. See standards(5) for
  information on when the _XOPEN_SOURCE_EXTENDED macro is defined.

RETURN VALUES
  Upon success, the basename() and dirname() functions return the component
  string. Upon failure, these functions return NULL. If there is no /
  (slash), the dirname() function returns a . (period).

  [Tru64 UNIX]	In applications that are compiled in an environment that
  excludes the _XOPEN_SOURCE_EXTENDED standard definitions, the dirname()
  function returns NULL if there is no / (slash).

  [Tru64 UNIX]	Upon successful completion, the dirname_r() function returns
  a value of 0 (zero) and places the directory name component in the buffer
  pointed at by buf. Upon failure (for example, if there is no / (slash)),
  the dirname_r() function returns -1 and sets errno.

ERRORS
  If the dirname_r() function fails, errno may be set to the following:

  [EINVAL]
      The value of the buf parameter is invalid or too small.

SEE ALSO
  Commands: basename(1)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for B

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