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Diffstat (limited to 'base/bin/slackwareutils/mktemp.1')
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diff --git a/base/bin/slackwareutils/mktemp.1 b/base/bin/slackwareutils/mktemp.1 new file mode 100644 index 0000000..11d56bd --- /dev/null +++ b/base/bin/slackwareutils/mktemp.1 @@ -0,0 +1,238 @@ +.\" $Id: mktemp.man,v 1.9 2001/11/12 19:47:06 millert Exp $ +.\" +.\" Copyright (c) 1996, 2000, 2001 Todd C. Miller <Todd.Miller@courtesan.com> +.\" 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. +.\" 3. The name of the author may not be used to endorse or promote products +.\" derived from this software without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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. +.\" +.TH MKTEMP 1 "30 September 2001" +.SH NAME +\fBmktemp\fP \- make temporary filename (unique) +.SH SYNOPSIS +\fBmktemp\fP [\fB\-V\fP] | [\fB\-dqtu\fP] [\fB\-p\fP \fIdirectory\fP] [\fItemplate\fP] +.SH DESCRIPTION +The +.B mktemp +utility takes the given filename +.I template +and overwrites a portion of it to create a unique filename. +The +.I template +may be any filename with six (6) +`Xs' appended to it, for example +.I /tmp/tfile.XXXXXX. +If no +.I template +is specified a default of +.I tmp.XXXXXX +is used and the +.B \-t +flag is implied (see below). +.PP +The trailing `Xs' are replaced with a combination +of the current process number and random letters. +.PP +If +.B mktemp +can successfully generate a unique filename, the file (or directory) +is created with file permissions such that it is only readable and writable +by its owner (unless the +.B \-u +flag is given) and the filename is printed to standard output. +.PP +.B mktemp +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 filename. +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 +.B mktemp +be used instead. +.PP +The options are as follows: +.TP +.B \-V +Print the version and exit. +.TP +.B \-d +Make a directory instead of a file. +.TP +.BI "\-p " directory +Use the specified +.I directory +as a prefix when generating the temporary filename. +The +.I directory +will be overridden by the user's +.SM TMPDIR +environment variable if it is set. +This option implies the +.B \-t +flag (see below). +.TP +.B \-q +Fail silently if an error occurs. +This is useful if +a script does not want error output to go to standard error. +.TP +.B \-t +Generate a path rooted in a temporary directory. +This directory is chosen as follows: +.RS +.IP \(bu +If the user's +.SM TMPDIR +environment variable is set, the directory contained therein is used. +.IP \(bu +Otherwise, if the +.B \-p +flag was given the specified directory is used. +.IP \(bu +If none of the above apply, +.I /tmp +is used. +.RE +.PP +In this mode, the +.I template +(if specified) should be a directory component (as opposed to a full path) +and thus should not contain any forward slashes. +.TP +.B \-u +Operate in ``unsafe'' mode. +The temp file will be unlinked before +.B mktemp +exits. This is slightly better than mktemp(3) +but still introduces a race condition. Use of this +option is not encouraged. +.PP +The +.B mktemp +utility +exits with a value of 0 on success or 1 on failure. +.Pp +Debian packages using +.Nm +in maintainer scripts must depend on debianutils >= 1.7. +.SH EXAMPLES +The following sh(1) +fragment illustrates a simple use of +.B mktemp +where the script should quit if it cannot get a safe +temporary file. +.RS +.nf + +TMPFILE=`mktemp /tmp/example.XXXXXX` || exit 1 +echo "program output" >> $TMPFILE + +.fi +.RE +The same fragment with support for a user's +.SM TMPDIR +environment variable can be written as follows. +.RS +.nf + +TMPFILE=`mktemp \-t example.XXXXXX` || exit 1 +echo "program output" >> $TMPFILE + +.fi +.RE +This can be further simplified if we don't care about the actual name of +the temporary file. In this case the +.B \-t +flag is implied. +.RS +.nf + +TMPFILE=`mktemp` || exit 1 +echo "program output" >> $TMPFILE + +.fi +.RE +In some cases, it may be desirable to use a default temporary directory +other than +.I /tmp. +In this example the temporary file will be created in +.I /extra/tmp +unless the user's +.SM TMPDIR +environment variable specifies otherwise. +.RS +.nf + +TMPFILE=`mktemp \-p /extra/tmp example.XXXXXX` || exit 1 +echo "program output" >> $TMPFILE + +.fi +.RE +In some cases, we want the script to catch the error. +For instance, if we attempt to create two temporary files and +the second one fails we need to remove the first before exiting. +.RS +.nf + +TMP1=`mktemp \-t example.1.XXXXXX` || exit 1 +TMP2=`mktemp \-t example.2.XXXXXX` +if [ $? \-ne 0 ]; then + rm \-f $TMP1 + exit 1 +fi + +.fi +.RE +Or perhaps you don't want to exit if +.B mktemp +is unable to create the file. +In this case you can protect that part of the script thusly. +.RS +.nf + +TMPFILE=`mktemp \-t example.XXXXXX` && { + # Safe to use $TMPFILE in this block + echo data > $TMPFILE + ... + rm \-f $TMPFILE +} + +.fi +.RE +.SH ENVIRONMENT +.IP TMPDIR 8 +directory in which to place the temporary file when in +.B \-t +mode +.SH SEE ALSO +.BR mkdtemp (3), +.BR mkstemp (3), +.BR mktemp (3) +.SH HISTORY +The +.B mktemp +utility appeared in OpenBSD 2.1. |