#! /bin/sh
# $Header: /home/jpeek/.lib/at_cron/RCS/ci_crontab 2.0 2002/09/19 13:47:21 jpeek Exp $
### ci_crontab - use RCS 'ci' command on your crontab file
### Usage: ci_crontab [directory-to-store-in]
##
##  Crontab files can be hard to configure and easy to lose.
##  This program uses the RCS ci command to check in a copy of the
##  crontab file.  If you name a directory on the command line, it stores
##  the file there.  Otherwise it tries the directories listed in $dirs.
##  The RCS file will be put in that directory (or its RCS subdirectory,
##  if there is one).  Crontab files that haven't changed aren't checked
##  in.  This script will call the file crontab.hostname, where hostname
##  is the local part of the hostname (foo.bar.com would be crontab.foo)
##
##  This is a great command to run automatically from the crontab
##  file, itself... or anytime you change the crontab.  For example:
##    alias ecron='crontab -e; ci_crontab'
##
##  This script is in the public domain.  Do whatever you want with it.
##  If you have comments or suggestions, please email them to me.
##     --Jerry Peek, jpeek@jpeek.com, 19 September 2002

# CONFIGURE these four lines (PATH may not be set by cron):
basename=/bin/basename   # Gets root of a pathname
cat=/bin/cat             # Outputs a file to stdout
ctcmd=/usr/bin/crontab   # Program for accessing crontab file
rcs=/usr/bin             # Directory where RCS commands live

dirs="$HOME/.lib/at_cron $HOME/.lib $HOME/lib $HOME" # Explained above
temp=/tmp/CI_CRONTB$$    # Temporary copy of crontab file

stat=1   # Default exit status (reset to 0 before normal exit)
trap '/bin/rm -f $temp; exit $stat' 0 1 2 15

hostname=`uname -n`
case "$hostname" in
*.*) hostname="`expr $hostname : '\([^.]*\)\.*'`" ;;  # Keep local part
esac
file=crontab.$hostname

# Check each directory in $1 (if any) and $dirs: does it exist and is
# it writable?  If so, that's the place we'll store the RCS file:
for dir in $1 $dirs
do
  if [ -d "$dir" -a -w "$dir" ]
  then
    cd "$dir" || exit

    # If old $file exists, move it out of the way:
    if [ -s $file ]
    then
      echo "`$basename $0`: renaming old $file to #$file" >>$temp
      mv $file \#$file || exit
    fi

    # If get here, have found a $file.  We'll exit before loop ends:
    $ctcmd -l > $file || exit           # Get copy of crontab file
    $rcs/rcsdiff -ko $file >>$temp 2>&1 # Compare (ignore keywords)
    case $? in
    0)  stat=0 ;;                       # No change.  Quit, no output
    1)  $cat $temp                      # Show command outputs 
        $rcs/rcs -l $file || exit       # Lock RCS so we can check in
        $rcs/ci -m'automatic checkin' $file || exit
        stat=0                          # If ci OK, set exit status
        ;;
    *)  $cat $temp 1>&2
        echo "`$basename $0` quitting: rcsdiff $file failed?" 1>&2
        ;;
    esac

    exit  # If we found a file, break loop and exit (at the trap)
  fi
done