1 .\" Copyright (C) 1993 David Metcalfe (david@prism.demon.co.uk)
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.
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.
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14 .\" manual page may be incorrect or out-of-date.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
21 .\" Formatted or processed versions of this manual, if unaccompanied by
22 .\" the source, must acknowledge the copyright and authors of this work.
25 .\" References consulted:
26 .\" Linux libc source code
27 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
29 .\" Modified Sat Jul 24 18:48:06 1993 by Rik Faith (faith@cs.unc.edu)
30 .\" Modified Fri Jun 23 01:26:34 1995 by Andries Brouwer (aeb@cwi.nl)
31 .\" (prompted by Scott Burkett <scottb@IntNet.net>)
32 .\" Modified Sun Mar 28 23:44:38 1999 by Andries Brouwer (aeb@cwi.nl)
34 .TH MKTEMP 3 2017-09-15 "GNU" "Linux Programmer's Manual"
36 mktemp \- make a unique temporary filename
39 .B #include <stdlib.h>
41 .BI "char *mktemp(char *" template );
45 Feature Test Macro Requirements for glibc (see
46 .BR feature_test_macros (7)):
55 (_XOPEN_SOURCE\ >=\ 500) && ! (_POSIX_C_SOURCE\ >=\ 200112L)
56 || /* Glibc since 2.19: */ _DEFAULT_SOURCE
57 || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
60 _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500
61 .\" || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
66 .IR "Never use this function" ;
71 function generates a unique temporary filename
73 The last six characters of \fItemplate\fP must
74 be XXXXXX and these are replaced with a string that makes the
76 Since it will be modified,
78 must not be a string constant, but should be declared as a character array.
82 function always returns \fItemplate\fP.
83 If a unique name was created, the last six bytes of \fItemplate\fP will
84 have been modified in such a way that the resulting name is unique
85 (i.e., does not exist already)
86 If a unique name could not be created,
87 \fItemplate\fP is made an empty string, and
89 is set to indicate the error.
93 The last six characters of \fItemplate\fP were not XXXXXX.
95 For an explanation of the terms used in this section, see
101 Interface Attribute Value
104 T} Thread safety MT-Safe
107 4.3BSD, POSIX.1-2001.
108 POSIX.1-2008 removes the specification of
111 .\" The prototype is in
113 .\" for libc4, libc5, glibc1; glibc2 follows the Single UNIX Specification
114 .\" and has the prototype in
119 Some implementations follow 4.3BSD
120 and replace XXXXXX by the current process ID and a single letter,
121 so that at most 26 different names can be returned.
122 Since on the one hand the names are easy to guess, and on the other
123 hand there is a race between testing whether the name exists and
124 opening the file, every use of
127 The race is avoided by