man3/tmpfile.3

   1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
   2 .\"
   3 .\" %%%LICENSE_START(VERBATIM)
   4 .\" Permission is granted to make and distribute verbatim copies of this
   5 .\" manual provided the copyright notice and this permission notice are
   6 .\" preserved on all copies.
   7 .\"
   8 .\" Permission is granted to copy and distribute modified versions of this
   9 .\" manual under the conditions for verbatim copying, provided that the
  10 .\" entire resulting derived work is distributed under the terms of a
  11 .\" permission notice identical to this one.
  12 .\"
  13 .\" Since the Linux kernel and libraries are constantly changing, this
  14 .\" manual page may be incorrect or out-of-date.  The author(s) assume no
  15 .\" responsibility for errors or omissions, or for damages resulting from
  16 .\" the use of the information contained herein.  The author(s) may not
  17 .\" have taken the same level of care in the production of this manual,
  18 .\" which is licensed free of charge, as they might when working
  19 .\" professionally.
  20 .\"
  21 .\" Formatted or processed versions of this manual, if unaccompanied by
  22 .\" the source, must acknowledge the copyright and authors of this work.
  23 .\" %%%LICENSE_END
  24 .\"
  25 .\" References consulted:
  26 .\"     Linux libc source code
  27 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
  28 .\"     386BSD man pages
  29 .\" Modified Sat Jul 24 17:46:57 1993 by Rik Faith (faith@cs.unc.edu)
  30 .\" Modified 2001-11-17, aeb
  31 .TH TMPFILE 3  2016-03-15 "" "Linux Programmer's Manual"
  32 .SH NAME
  33 tmpfile \- create a temporary file
  34 .SH SYNOPSIS
  35 .nf
  36 .B #include <stdio.h>
  37 .sp
  38 .B FILE *tmpfile(void);
  39 .fi
  40 .SH DESCRIPTION
  41 The
  42 .BR tmpfile ()
  43 function opens a unique temporary file
  44 in binary read/write (w+b) mode.
  45 The file will be automatically deleted when it is closed or the
  46 program terminates.
  47 .SH RETURN VALUE
  48 The
  49 .BR tmpfile ()
  50 function returns a stream descriptor, or NULL if
  51 a unique filename cannot be generated or the unique file cannot be
  52 opened.
  53 In the latter case,
  54 .I errno
  55 is set to indicate the error.
  56 .SH ERRORS
  57 .TP
  58 .B EACCES
  59 Search permission denied for directory in file's path prefix.
  60 .TP
  61 .B EEXIST
  62 Unable to generate a unique filename.
  63 .TP
  64 .B EINTR
  65 The call was interrupted by a signal; see
  66 .BR signal (7).
  67 .TP
  68 .B EMFILE
  69 The per-process limit on the number of open file descriptors has been reached.
  70 .TP
  71 .B ENFILE
  72 The system-wide limit on the total number of open files has been reached.
  73 .TP
  74 .B ENOSPC
  75 There was no room in the directory to add the new filename.
  76 .TP
  77 .B EROFS
  78 Read-only filesystem.
  79 .SH ATTRIBUTES
  80 For an explanation of the terms used in this section, see
  81 .BR attributes (7).
  82 .TS
  83 allbox;
  84 lb lb lb
  85 l l l.
  86 Interface       Attribute       Value
  87 T{
  88 .BR tmpfile ()
  89 T}      Thread safety   MT-Safe
  90 .TE
  91 .SH CONFORMING TO
  92 POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD, SUSv2.
  93 .SH NOTES
  94 POSIX.1-2001 specifies:
  95 an error message may be written to
  96 .I stdout
  97 if the stream
  98 cannot be opened.
  99 .LP
 100 The standard does not specify the directory that
 101 .BR tmpfile ()
 102 will use.
 103 Glibc will try the path prefix
 104 .I P_tmpdir
 105 defined
 106 in
 107 .IR <stdio.h> ,
 108 and if that fails the directory
 109 .IR /tmp .
 110 .SH SEE ALSO
 111 .BR exit (3),
 112 .BR mkstemp (3),
 113 .BR mktemp (3),
 114 .BR tempnam (3),
 115 .BR tmpnam (3)