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diff --git a/man3/mkstemp.3 b/man3/mkstemp.3 new file mode 100644 index 0000000..dbfa252 --- /dev/null +++ b/man3/mkstemp.3 @@ -0,0 +1,248 @@ +'\" t +.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) +.\" and Copyright (C) 2008, Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" References consulted: +.\" Linux libc source code +.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) +.\" 386BSD man pages +.\" Modified Sat Jul 24 18:48:48 1993 by Rik Faith (faith@cs.unc.edu) +.\" Modified 980310, aeb +.\" Modified 990328, aeb +.\" 2008-06-19, mtk, Added mkostemp(); various other changes +.\" +.TH mkstemp 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +mkstemp, mkostemp, mkstemps, mkostemps \- create a unique temporary file +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <stdlib.h> +.PP +.BI "int mkstemp(char *" template ); +.BI "int mkostemp(char *" template ", int " flags ); +.BI "int mkstemps(char *" template ", int " suffixlen ); +.BI "int mkostemps(char *" template ", int " suffixlen ", int " flags ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR mkstemp (): +.nf + _XOPEN_SOURCE >= 500 +.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED + || /* glibc >= 2.12: */ _POSIX_C_SOURCE >= 200809L + || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE +.fi +.PP +.BR mkostemp (): +.nf + _GNU_SOURCE +.fi +.PP +.BR mkstemps (): +.nf + /* glibc >= 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE +.fi +.PP +.BR mkostemps (): +.nf + _GNU_SOURCE +.fi +.SH DESCRIPTION +The +.BR mkstemp () +function generates a unique temporary filename from +.IR template , +creates and opens the file, +and returns an open file descriptor for the file. +.PP +The last six characters of +.I template +must be "XXXXXX" and these are replaced with a string that makes the +filename unique. +Since it will be modified, +.I template +must not be a string constant, but should be declared as a character array. +.PP +The file is created with +permissions 0600, that is, read plus write for owner only. +The returned file descriptor provides both read and write access to the file. +The file is opened with the +.BR open (2) +.B O_EXCL +flag, guaranteeing that the caller is the process that creates the file. +.PP +The +.BR mkostemp () +function is like +.BR mkstemp (), +with the difference that the following bits\[em]with the same meaning as for +.BR open (2)\[em]may +be specified in +.IR flags : +.BR O_APPEND , +.BR O_CLOEXEC , +and +.BR O_SYNC . +Note that when creating the file, +.BR mkostemp () +includes the values +.BR O_RDWR , +.BR O_CREAT , +and +.B O_EXCL +in the +.I flags +argument given to +.BR open (2); +including these values in the +.I flags +argument given to +.BR mkostemp () +is unnecessary, and produces errors on some +.\" Reportedly, FreeBSD +systems. +.PP +The +.BR mkstemps () +function is like +.BR mkstemp (), +except that the string in +.I template +contains a suffix of +.I suffixlen +characters. +Thus, +.I template +is of the form +.IR "prefixXXXXXXsuffix" , +and the string XXXXXX is modified as for +.BR mkstemp (). +.PP +The +.BR mkostemps () +function is to +.BR mkstemps () +as +.BR mkostemp () +is to +.BR mkstemp (). +.SH RETURN VALUE +On success, these functions return the file descriptor +of the temporary file. +On error, \-1 is returned, and +.I errno +is set to indicate the error. +.SH ERRORS +.TP +.B EEXIST +Could not create a unique temporary filename. +Now the contents of \fItemplate\fP are undefined. +.TP +.B EINVAL +For +.BR mkstemp () +and +.BR mkostemp (): +The last six characters of \fItemplate\fP were not XXXXXX; +now \fItemplate\fP is unchanged. +.IP +For +.BR mkstemps () +and +.BR mkostemps (): +.I template +is less than +.I "(6 + suffixlen)" +characters long, or the last 6 characters before the suffix in +.I template +were not XXXXXX. +.PP +These functions may also fail with any of the errors described for +.BR open (2). +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR mkstemp (), +.BR mkostemp (), +.BR mkstemps (), +.BR mkostemps () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +.TP +.BR mkstemp () +POSIX.1-2001. +.TP +.BR mkstemps () +BSD. +.\" mkstemps() appears to be at least on the BSDs, Mac OS X, Solaris, +.\" and Tru64. +.TP +.BR mkostemp () +.TQ +.BR mkostemps () +GNU. +.SH HISTORY +.TP +.BR mkstemp () +4.3BSD, POSIX.1-2001. +.TP +.BR mkstemps () +glibc 2.11. +BSD, Mac OS X, Solaris, Tru64. +.TP +.BR mkostemp () +glibc 2.7. +.TP +.BR mkostemps () +glibc 2.11. +.PP +In glibc versions 2.06 and earlier, the file is created with permissions 0666, +that is, read and write for all users. +This old behavior may be +a security risk, especially since other UNIX flavors use 0600, +and somebody might overlook this detail when porting programs. +POSIX.1-2008 adds a requirement that the file be created with mode 0600. +.PP +More generally, the POSIX specification of +.BR mkstemp () +does not say anything +about file modes, so the application should make sure its +file mode creation mask (see +.BR umask (2)) +is set appropriately before calling +.BR mkstemp () +(and +.BR mkostemp ()). +.\" +.\" The prototype for +.\" .BR mkstemp () +.\" is in +.\" .I <unistd.h> +.\" for libc4, libc5, glibc1; glibc2 follows POSIX.1 and has the prototype in +.\" .IR <stdlib.h> . +.SH SEE ALSO +.BR mkdtemp (3), +.BR mktemp (3), +.BR tempnam (3), +.BR tmpfile (3), +.BR tmpnam (3) |