Linux Pocket Guide, 2nd Edition

Break and Continue

The break command jumps out of the nearest enclosing loop. Consider this simple script called myscript:

for name in Tom Jack Harry
do
  echo $name
  echo "again"
done
echo "all done"

$ ./myscript
Tom
again
Jack
again
Harry
again
all done

Now with a break:

for name in Tom Jack Harry
do
  echo $name
  if [ "$name" = "Jack" ]
  then
    break
  fi
  echo "again"
done
echo "all done"

$ ./myscript
Tom
again
Jack            The break occurs after this line
all done

The continue command forces a loop to jump to its next iteration.

for name in Tom Jack Harry
do
  echo $name
  if [ "$name" = "Jack" ]
  then
    continue
  fi
  echo "again"
done
echo "all done"

$ ./myscript
Tom
again
Jack          The continue occurs after this line
Harry
again
all done

break and continue also accept a numeric argument (break N, continue N) to control multiple layers of loops (e.g., jump out of N layers of loops), but this kind of scripting leads to spaghetti code and we don’t recommend it.