man3/tmpfile.3

   1 '\" t
   2 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
   3 .\"
   4 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   5 .\"
   6 .\" References consulted:
   7 .\"     Linux libc source code
   8 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
   9 .\"     386BSD man pages
  10 .\" Modified Sat Jul 24 17:46:57 1993 by Rik Faith (faith@cs.unc.edu)
  11 .\" Modified 2001-11-17, aeb
  12 .TH tmpfile 3 (date) "Linux man-pages (unreleased)"
  13 .SH NAME
  14 tmpfile \- create a temporary file
  15 .SH LIBRARY
  16 Standard C library
  17 .RI ( libc ", " \-lc )
  18 .SH SYNOPSIS
  19 .nf
  20 .B #include <stdio.h>
  21 .P
  22 .B FILE *tmpfile(void);
  23 .fi
  24 .SH DESCRIPTION
  25 The
  26 .BR tmpfile ()
  27 function opens a unique temporary file
  28 in binary read/write (w+b) mode.
  29 The file will be automatically deleted when it is closed or the
  30 program terminates.
  31 .SH RETURN VALUE
  32 The
  33 .BR tmpfile ()
  34 function returns a stream descriptor, or NULL if
  35 a unique filename cannot be generated or the unique file cannot be
  36 opened.
  37 In the latter case,
  38 .I errno
  39 is set to indicate the error.
  40 .SH ERRORS
  41 .TP
  42 .B EACCES
  43 Search permission denied for directory in file's path prefix.
  44 .TP
  45 .B EEXIST
  46 Unable to generate a unique filename.
  47 .TP
  48 .B EINTR
  49 The call was interrupted by a signal; see
  50 .BR signal (7).
  51 .TP
  52 .B EMFILE
  53 The per-process limit on the number of open file descriptors has been reached.
  54 .TP
  55 .B ENFILE
  56 The system-wide limit on the total number of open files has been reached.
  57 .TP
  58 .B ENOSPC
  59 There was no room in the directory to add the new filename.
  60 .TP
  61 .B EROFS
  62 Read-only filesystem.
  63 .SH ATTRIBUTES
  64 For an explanation of the terms used in this section, see
  65 .BR attributes (7).
  66 .TS
  67 allbox;
  68 lbx lb lb
  69 l l l.
  70 Interface       Attribute       Value
  71 T{
  72 .na
  73 .nh
  74 .BR tmpfile ()
  75 T}      Thread safety   MT-Safe
  76 .TE
  77 .SH VERSIONS
  78 The standard does not specify the directory that
  79 .BR tmpfile ()
  80 will use.
  81 glibc will try the path prefix
  82 .I P_tmpdir
  83 defined
  84 in
  85 .IR <stdio.h> ,
  86 and if that fails, then the directory
  87 .IR /tmp .
  88 .SH STANDARDS
  89 C11, POSIX.1-2008.
  90 .SH HISTORY
  91 POSIX.1-2001, C89, SVr4, 4.3BSD, SUSv2.
  92 .SH NOTES
  93 POSIX.1-2001 specifies:
  94 an error message may be written to
  95 .I stdout
  96 if the stream
  97 cannot be opened.
  98 .SH SEE ALSO
  99 .BR exit (3),
 100 .BR mkstemp (3),
 101 .BR mktemp (3),
 102 .BR tempnam (3),
 103 .BR tmpnam (3)