petr-korobeinikov mktemp-d
Never create a temporary file or directory at a hardcoded path
under /tmp.
Always allocate a private directory with mktemp -d
and place all temporary artifacts inside it.
Why
mktemp -d returns a unique, private directory.
A hardcoded path under /tmp does not —
it collides with concurrent runs and any leftover state from prior runs.
Rule
One mktemp -d per logical scope, then build paths inside it:
tmpdir=$(mktemp -d)
cp something "$tmpdir/input"
do_work > "$tmpdir/output.log"
Direct substitutions
| Don't | Do |
|---|---|
mkdir /tmp/work |
work=$(mktemp -d) |
touch /tmp/out.log |
work=$(mktemp -d); : > "$work/out.log" |
cmd > /tmp/output |
work=$(mktemp -d); cmd > "$work/output" |
tar xf x.tar -C /tmp |
work=$(mktemp -d); tar xf x.tar -C "$work" |
If you encounter a hardcoded /tmp/... path while editing a file,
replace it with the mktemp -d idiom as part of the same edit.