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tmpnam(3)
NAME
  tmpnam, tempnam - Construct the name for a temporary file

SYNOPSIS
  #include <stdio.h>

  char *tmpnam(
	  char *s );

  char *tempnam(
	  const char *directory,
	  const char *prefix );

LIBRARY
  Standard C Library (libc)

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

  tmpnam(), tempnam():	XSH4.2

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

PARAMETERS
  s   Specifies the address of an array of at least the number of bytes
      specified by L_tmpnam, a constant defined in the stdio.h header file.

  directory
      Points to the pathname of the directory in which the file is to be
      created.

  prefix
      Points to an initial letter sequence with which the filename begins.
      The prefix parameter can be null, or it can point to a string of up to
      5 bytes to be used as the beginning of the temporary filename.

DESCRIPTION
  The tmpnam() and tempnam() functions generate filenames for temporary
  files.

  The tmpnam() function generates a filename using the pathname defined as
  P_tmpdir in the stdio.h header file.

  Files created using this function reside in a directory intended for
  temporary use, and their names are unique. It is the application's
  responsibility to use the unlink() function to remove the files when they
  are no longer needed.

  Between the time a filename is created and the file is opened, it is
  possible for some other process to create a file with the same name. This
  should not happen if that other process uses these functions or the
  mktemp() function, and if the filenames are chosen to make duplication by
  other means unlikely.

  The tempnam() function allows you to control the choice of a directory. If
  the directory parameter is null or points to a string that is not a
  pathname for an appropriate directory, the pathname defined as P_tmpdir in
  the stdio.h header file is used. If that pathname is not accessible, /tmp
  is used. You can bypass the selection of a pathname by providing an
  environment variable, TMPDIR, in the user's environment.  The value of the
  TMPDIR variable is a pathname for the desired temporary file directory.

  The prefix parameter can be used to specify a prefix of up to 5 bytes for
  the temporary filename.

NOTES
  If the s parameter is null, the tmpnam() function places its result into an
  internal thread-specific buffer and returns a pointer to that area.
  Subsequent calls to this function from the same thread overwrite this
  buffer.

  The tmpnam() function generates a different filename each time it is
  called.

  [Tru64 UNIX]	If tmpnam() is called more than TMP_MAX times by a single
  process, it starts recycling previously used names.

RETURN VALUES
  If the s parameter is null, tmpnam() function places its result into an
  internal thread-specific buffer and returns a pointer to that area.

  If the s parameter is not null, it is assumed to be the address of an array
  of at least the number of bytes specified by the L_tmpnam constant. The
  tmpnam() function places its results into that array and returns the value
  of the s parameter.

  Upon successful completion, the tempnam() function returns a pointer to the
  generated pathname, suitable for use in a subsequent call to the free()
  function. Otherwise, null is returned and errno is set to indicate the
  error.

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

  [ENOMEM]
      Insufficient storage space is available.

SEE ALSO
  Functions: fopen(3), free(3), malloc(3), mktemp(3), open(2), tmpfile(3),
  unlink(2)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for T

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