When looking at ps2epsi, I noticed some details in the tempfile creation that should be improved:

if which mktemp >/dev/null 2>/dev/null; then
    tmpfile="`mktemp $TMPDIR/ps2epsi.XXXXXX`"

adding   || exit 1   might be a good idea so that ps2epsi exits if it can't create a tempfile. (mktemp should print an error message in this case, no need to print another one.)

else
    tmpdir=$TMPDIR/ps2epsi.$$
    (umask 077 && mkdir "$tmpdir")
    if test ! -d "$tmpdir"; then
        echo "failed: could not create temporary file"
        exit 1
    fi
    tmpfile="$tmpdir"/ps2epsi$$
fi

The fallback (if mktemp can't be found) isn't terribly bad, but still insecure. In theory someone could create /tmp/ps2epsi.$$ before (one for each possible pid) and create a ps2epsi$$ symlink in it to overwrite an attacker-chosen file (aka "symlink attack").

The good thing is that mkdir errors out if a directory already exists, so all you need is to check its exit code:

    (umask 077 && mkdir "$tmpdir") || { 
        echo "$tmpdir can't be created or unexpectedly already exists, 
             abortingfor security reasons" >&2 ; 
        exit 1 ;
    }

(You can also test for $? != 0 if you don't like the "||" syntax.)

In theory checking $? should make the "test ! -d" superfluous, but in practise it can't hurt to keep it.


For completeness: "mkdir -p" will not error out on existing directories, so better don't use it in scripts ;-)