from.sh

Shall高级编程

#!/bin/bash
# from.sh

#  Emulates the useful "from" utility in Solaris, BSD, etc.
#  Echoes the "From" header line in all messages
#+ in your e-mail directory.


MAILDIR=~/mail/*               #  No quoting of variable. Why?
GREP_OPTS="-H -A 5 --color"    #  Show file, plus extra context lines
                               #+ and display "From" in color.
TARGETSTR="^From"              # "From" at beginning of line.

for file in $MAILDIR           #  No quoting of variable.
do
  grep $GREP_OPTS "$TARGETSTR" "$file"
  #    ^^^^^^^^^^              #  Again, do not quote this variable.
  echo
done

exit $?

#  Might wish to pipe the output of this script to 'more' or
#+ redirect it to a file . . .