for

for x [in list]
do
    commands
done

For variable x (in optional list of values) do commands. If in list is omitted, "$@" (the positional parameters) is assumed.

Examples

Paginate files specified on the command line; save each result:

for file; do
     pr $file > $file.tmp
done

Search chapters for a list of words (like fgrep -f):

for item in `cat program_list`
do
     echo "Checking chapters for"
     echo "references to program $item..."
     grep -c "$item.[co]" chap*
done

Extract a one-word title from each file and use as new filename:

for file
do
     name=`sed -n 's/NAME: //p' $file`
     mv $file $name
done