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Diffstat (limited to 'shell_cmds/mktemp/mktemp.1')
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diff --git a/shell_cmds/mktemp/mktemp.1 b/shell_cmds/mktemp/mktemp.1 new file mode 100644 index 0000000..921ffa3 --- /dev/null +++ b/shell_cmds/mktemp/mktemp.1 @@ -0,0 +1,215 @@ +.\" Copyright (c) 1989, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" From: $OpenBSD: mktemp.1,v 1.8 1998/03/19 06:13:37 millert Exp $ +.\" $FreeBSD$ +.\" +.Dd December 30, 2005 +.Dt MKTEMP 1 +.Os +.Sh NAME +.Nm mktemp +.Nd make temporary file name (unique) +.Sh SYNOPSIS +.Nm +.Op Fl d +.Op Fl q +.Op Fl t Ar prefix +.Op Fl u +.Ar template ... +.Nm +.Op Fl d +.Op Fl q +.Op Fl u +.Fl t Ar prefix +.Sh DESCRIPTION +The +.Nm +utility takes each of the given file name templates and overwrites a +portion of it to create a file name. +This file name is unique +and suitable for use by the application. +The template may be +any file name with some number of +.Ql X Ns s +appended +to it, for example +.Pa /tmp/temp.XXXX . +The trailing +.Ql X Ns s +are replaced with the current process number and/or a +unique letter combination. +The number of unique file names +.Nm +can return depends on the number of +.Ql X Ns s +provided; six +.Ql X Ns s +will +result in +.Nm +selecting 1 of 56800235584 (62 ** 6) possible file names. +On case-insensitive file systems, the effective number of unique +names is significantly less; given six +.Ql X Ns s , +.Nm +will instead select 1 of 2176782336 (36 ** 6) possible unique file names. +.Pp +If +.Nm +can successfully generate a unique file name, the file +is created with mode 0600 (unless the +.Fl u +flag is given) and the filename is printed +to standard output. +.Pp +If the +.Fl t Ar prefix +option is given, +.Nm +will generate a template string based on the +.Ar prefix +and the +.Dv _CS_DARWIN_USER_TEMP_DIR +configuration variable if available. +Fallback locations if +.Dv _CS_DARWIN_USER_TEMP_DIR +is not available are +.Ev TMPDIR +and +.Pa /tmp . +Care should +be taken to ensure that it is appropriate to use an environment variable +potentially supplied by the user. +.Pp +If no arguments are passed or if only the +.Fl d +flag is passed +.Nm +behaves as if +.Fl t Li tmp +was supplied. +.Pp +Any number of temporary files may be created in a single invocation, +including one based on the internal template resulting from the +.Fl t +flag. +.Pp +The +.Nm +utility is provided to allow shell scripts to safely use temporary files. +Traditionally, many shell scripts take the name of the program with +the pid as a suffix and use that as a temporary file name. +This +kind of naming scheme is predictable and the race condition it creates +is easy for an attacker to win. +A safer, though still inferior, approach +is to make a temporary directory using the same naming scheme. +While +this does allow one to guarantee that a temporary file will not be +subverted, it still allows a simple denial of service attack. +For these +reasons it is suggested that +.Nm +be used instead. +.Sh OPTIONS +The available options are as follows: +.Bl -tag -width indent +.It Fl d +Make a directory instead of a file. +.It Fl q +Fail silently if an error occurs. +This is useful if +a script does not want error output to go to standard error. +.It Fl t Ar prefix +Generate a template (using the supplied +.Ar prefix +and +.Ev TMPDIR +if set) to create a filename template. +.It Fl u +Operate in +.Dq unsafe +mode. +The temp file will be unlinked before +.Nm +exits. +This is slightly better than +.Xr mktemp 3 +but still introduces a race condition. +Use of this +option is not encouraged. +.El +.Sh EXIT STATUS +.Ex -std +.Sh EXAMPLES +The following +.Xr sh 1 +fragment illustrates a simple use of +.Nm +where the script should quit if it cannot get a safe +temporary file. +.Bd -literal -offset indent +tempfoo=`basename $0` +TMPFILE=`mktemp /tmp/${tempfoo}.XXXXXX` || exit 1 +echo "program output" >> $TMPFILE +.Ed +.Pp +To allow the use of $TMPDIR: +.Bd -literal -offset indent +tempfoo=`basename $0` +TMPFILE=`mktemp -t ${tempfoo}` || exit 1 +echo "program output" >> $TMPFILE +.Ed +.Pp +In this case, we want the script to catch the error itself. +.Bd -literal -offset indent +tempfoo=`basename $0` +TMPFILE=`mktemp -q /tmp/${tempfoo}.XXXXXX` +if [ $? -ne 0 ]; then + echo "$0: Can't create temp file, exiting..." + exit 1 +fi +.Ed +.Sh SEE ALSO +.Xr mkdtemp 3 , +.Xr mkstemp 3 , +.Xr mktemp 3 , +.Xr confstr 3 , +.Xr environ 7 +.Sh HISTORY +A +.Nm +utility appeared in +.Ox 2.1 . +This implementation was written independently based on the +.Ox +man page, and +first appeared in +.Fx 2.2.7 . +This man page is taken from +.Ox . |