mktemp & trap in Bash

Private scratch space that cleans itself up.

# mktemp hands out a private scratch file or directory
work=$(mktemp -d)
trap 'rm -rf "$work"' EXIT

echo "working in $work"
printf 'draft\n' > "$work/notes.txt"
cp "$work/notes.txt" "$work/notes.bak"

ls "$work" | sort
# no rm needed here: the trap cleans up on exit

How it works

1. mktemp -d makes a directory only this run knows.
2. The trap ... EXIT removes it on any exit path.
3. Work inside is free to create and copy without fear.

Keywords and builtins used here

• echo
• printf
• trap

The run, in numbers

Lines

10

Characters to type

267

Tokens

48

Three-star pace

85 tpm

At the three-star pace of 85 tokens a minute, this run takes about 34 seconds.

Type this snippet

Step 3 of 3 in Scripts & safety, step 24 of 26 in Language basics.

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