man3/tmpfile.3

   1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
   2 .\"
   3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   4 .\"
   5 .\" References consulted:
   6 .\"     Linux libc source code
   7 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
   8 .\"     386BSD man pages
   9 .\" Modified Sat Jul 24 17:46:57 1993 by Rik Faith (faith@cs.unc.edu)
  10 .\" Modified 2001-11-17, aeb
  11 .TH tmpfile 3 (date) "Linux man-pages (unreleased)"
  12 .SH NAME
  13 tmpfile \- create a temporary file
  14 .SH LIBRARY
  15 Standard C library
  16 .RI ( libc ", " \-lc )
  17 .SH SYNOPSIS
  18 .nf
  19 .B #include <stdio.h>
  20 .PP
  21 .B FILE *tmpfile(void);
  22 .fi
  23 .SH DESCRIPTION
  24 The
  25 .BR tmpfile ()
  26 function opens a unique temporary file
  27 in binary read/write (w+b) mode.
  28 The file will be automatically deleted when it is closed or the
  29 program terminates.
  30 .SH RETURN VALUE
  31 The
  32 .BR tmpfile ()
  33 function returns a stream descriptor, or NULL if
  34 a unique filename cannot be generated or the unique file cannot be
  35 opened.
  36 In the latter case,
  37 .I errno
  38 is set to indicate the error.
  39 .SH ERRORS
  40 .TP
  41 .B EACCES
  42 Search permission denied for directory in file's path prefix.
  43 .TP
  44 .B EEXIST
  45 Unable to generate a unique filename.
  46 .TP
  47 .B EINTR
  48 The call was interrupted by a signal; see
  49 .BR signal (7).
  50 .TP
  51 .B EMFILE
  52 The per-process limit on the number of open file descriptors has been reached.
  53 .TP
  54 .B ENFILE
  55 The system-wide limit on the total number of open files has been reached.
  56 .TP
  57 .B ENOSPC
  58 There was no room in the directory to add the new filename.
  59 .TP
  60 .B EROFS
  61 Read-only filesystem.
  62 .SH ATTRIBUTES
  63 For an explanation of the terms used in this section, see
  64 .BR attributes (7).
  65 .ad l
  66 .nh
  67 .TS
  68 allbox;
  69 lbx lb lb
  70 l l l.
  71 Interface       Attribute       Value
  72 T{
  73 .BR tmpfile ()
  74 T}      Thread safety   MT-Safe
  75 .TE
  76 .hy
  77 .ad
  78 .sp 1
  79 .SH STANDARDS
  80 POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD, SUSv2.
  81 .SH NOTES
  82 POSIX.1-2001 specifies:
  83 an error message may be written to
  84 .I stdout
  85 if the stream
  86 cannot be opened.
  87 .PP
  88 The standard does not specify the directory that
  89 .BR tmpfile ()
  90 will use.
  91 Glibc will try the path prefix
  92 .I P_tmpdir
  93 defined
  94 in
  95 .IR <stdio.h> ,
  96 and if that fails, then the directory
  97 .IR /tmp .
  98 .SH SEE ALSO
  99 .BR exit (3),
 100 .BR mkstemp (3),
 101 .BR mktemp (3),
 102 .BR tempnam (3),
 103 .BR tmpnam (3)