Most systems I\'ve encountered have both tempfile(1)
and mktemp(1)
. There are syntactic differences, and mktemp
can also create directorie
I suspect there's some interesting Unix lore behind this ...
The history of mktemp
can be traced to OpenBSD 2.1. However, it became a part of GNU coreutils much later. This post announced the inclusion of mktemp
for coreutils
.
Until then, tempfile
was being used by a number of programs. There was also a proposal to make tempfile
a wrapper around mktemp
, which was rejected to discourage use of tempfile
.
However, the following was added to tempfile
manual:
Exclusive creation is not guaranteed when creating files on NFS partitions.
tempfile
cannot make temporary directories.tempfile
is deprecated; you should usemktemp(1)
instead.
From the source code sight of things (on debian) tempfile
is from the package debianutils
and uses the libc function tempnam()
while mktemp
is from GNU coreutils and doesn't use the libc function
It says in tempfile's manual that:
tempfile - create a temporary file in a safe manner
While in mktemp:
mktemp - create a temporary file or directory
They're probably just almost the same, only that the implementation is a little different.
As said in the manual, tempfile
actually has some precautions like:
a) In case the environment variable
TMPDIR
exists and contains the name of an appropriate directory, that is used.b) Otherwise, if the
--directory
argument is specified and appropriate, it is used.c) Otherwise,
P_tmpdir
(as defined in<stdio.h>
) is used when appropriate.d) Finally an implementation-defined directory (
/tmp
) may be used.
It's actually useful if the script trusts mktemp
or tempfile
enough that it's certain that a temporary file or directory would be created. But I don't see much problem just using mktemp
if you run precautions in your script yourself. You can use [ -e ]
, [ -f ]
, [ -d ]
, [ -L ]
, etc. to verify if a file could actually be made/was already made. Even check if something's writable, readable, and/or executable with -r, -w and -x. In bash, see help test
.
Still for the sake of continuous runtime perhaps you would better rely on tempfile
when running your code in multiple environments. Just make sure that it's available everywhere enough. With which
or with type -P
you could check which one of them is available. An example:
create_temp() {
if type -P tempfile >/dev/null; then
# use tempfile based from $1
elif type -P mktemp > /dev/null; then
# use mktemp based from $1
else
echo "Can't find temporary file creator."
exit 1
fi
}