TMPFILE(3S)                                                        TMPFILE(3S)


NAME
     tmpfile - create a temporary file

SYNOPSIS
     #include <stdio.h>

     FILE *tmpfile (void);

DESCRIPTION
     tmpfile creates a temporary file, and returns a corresponding FILE
     pointer.  The file is created on the temporary directory indicated by the
     string P_tmpdir in <stdio.h>.  However, if the variable TMPDIR is
     provided in the user's environment, the variable's value is the name of
     the desired temporary-file directory.  If the directory specified by the
     variable TMPDIR is not accessible, the directory specified by the string
     P_tmpdir in <stdio.h> will be used.

     If the file cannot be opened, a NULL pointer is returned.  Upon return
     from tmpfile, you may print an error message using perror(3C), to
     determine the reason for the failure.  A success call to tmpfile will
     create a temporary file just long enough to obtain the FILE pointer, then
     delete the file with unlink(2), and finally return the FILE pointer to
     the calling process.  Thus, the only means of accessing the temporary
     file is though the FILE pointer.  The file is opened for update ("w+").

     Although the name of the temporary file is generated similarly to those
     produced by tmpnam(3S), tmpfile uses its own algorithm to generate
     filenames similar to, but unique from, those generated by tmpnam.  This
     allocates the entire space of tmpnam-generated names to applications
     code. (See tmpnam(3S) for more information.)

ENVIRONMENT VARIABLES
     TMPDIR
          If the environment variable TMPDIR is provided, it is used as the
          desired temporary-file directory. The support for the TMPDIR
          environment variable is introduced in IRIX 6.5.9.

SEE ALSO
     creat(2), unlink(2), fopen(3S), mktemp(3C), perror(3C), stdio(3S),
     tmpnam(3S).


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