mkstemp(3)         UNIX System V(BSD Compatibility Package)          mkstemp(3)


NAME
      mkstemp - make a unique file name

SYNOPSIS
      cc [ flag. . . ] file . . . -lucb

      mkstemp(template)
      char *template;

DESCRIPTION
      mkstemp creates a unique file name, typically in a temporary filesystem,
      by replacing template with a unique file name, and returns a file
      descriptor for the template file open for reading and writing.  The
      string in template should contain a file name with six trailing Xs;
      mkstemp replaces the Xs with a letter and the current process ID. The
      letter will be chosen so that the resulting name does not duplicate an
      existing file.  mkstemp avoids the race between testing whether the file
      exists and opening it for use.

SEE ALSO
      getpid(2), open(2), tmpfile(3S), tmpnam(3S) in the Programmer's Reference
      Manual

RETURN VALUE
      mkstemp returns -1 if no suitable file could be created.

NOTES
      It is possible to run out of letters.

      mkstemp actually changes the template string which you pass; this means
      that you cannot use the same template string more than once - you need a
      fresh template for every unique file you want to open.

      When mkstemp is creating a new unique filename it checks for the prior
      existence of a file with that name.  This means that if you are creating
      more than one unique filename, it is bad practice to use the same root
      template for multiple invocations of mkstemp.

















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