Temporary Files

A script may need to create temporary files to hold intermediate results. The safest way to do this is to use mktemp which returns a currently unused name. The following command creates a new file in /tmp.

newfile=$(mktemp -c -d /tmp)

If a script is prematurely aborted (the user may press ^C for example) it's good practise to remove any temporary files. The trap command can be used to run a tidy-up routine when the script (for whatever reason) exits. To see this in action start the following script then press ^C

newfile=$(mktemp -c -d /tmp)
  trap "echo Removing $newfile ; rm -f $newfile" 0
  sleep 100