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mktemp(3)
NAME
  mktemp, mkstemp - Construct a unique file name

LIBRARY
  Standard C Library (libc.so, libc.a),

  System V Compatibility Library (libsys5.a)

SYNOPSIS
  Standard C Library

  #include <stdlib.h>

  int mkstemp(
	  char *template);

  char *mktemp(
	  char *template);

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

  mktemp(), mkstemp():	XPG4-UNIX

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

PARAMETERS
  template
      Points to a string to be replaced with a unique file name.  The string
      in the template parameter must be a file name with six trailing Xs.

DESCRIPTION
  The mktemp() function replaces the contents of the string pointed to by the
  template parameter with a unique file name.  The application must
  initialize template to be a file name with six trailing Xs; mktemp()
  replaces the Xs in the template string with a unique file name.  Under
  libc.a, the file name is a unique combination of the thread name and
  process ID.  Under libsys5.a, the file name is created with the getpid
  function.

  The mkstemp() function performs the same substitution to the template name
  and also returns a file descriptor for the file and opens the file with
  "owner" reading and writing privileges (0600). The function thus prevents
  any possible race condition between testing whether the file exists and
  opening it for use.  The mkstemp() function is not available under
  libsys5.a.

RETURN VALUES
  Upon successful completion, the mktemp() function returns the address of
  the string pointed to by the template parameter.

  If the string pointed to by the template parameter contains no Xs, or if
  the mktemp() function is unable to construct a unique file name, the first
  character of the template parameter string is replaced with a null
  character, and a null pointer is returned.

  Upon successful completion, the mkstemp() function returns an open file
  descriptor. If the mkstemp() function fails, it returns a value of -1.

ERRORS
  No errors are defined for this routine.

RELATED INFORMATION
  Functions: tmpfile(3), tmpnam(3), getpid(2)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for M

Top of page