#!/usr/bin/perl
# script to show users' csh history with dates
# ammended to add support for displaying all user's history files
# on a given date (switch -d)
# useful for running daily from a cron job and having 
# the output mailed to an admin

=comment
Addendum - the shell script I run from cron around
11.50pm daily is as follows:
#!/bin/sh
TODAY=`date | awk '{print $2,$3}'

/home/munk/bin/perl/showhistory.pl -d "$TODAY"
=cut

use strict;
use Getopt::Std;

my %opt=();
my($user, $date, $histdate, $histfile, $err);
my $div="#"x68;

my $progname = $0;
$progname =~ s,.*/,,;  # use basename only
$progname =~ s/\.\w*$//; # strip extension, if any

# find out what options we're passed:
&getopts('u:d:h', \%opt);

# display usage if bad opts:
if($opt{h}){ &usage(); }

# parse options:
if($opt{u}){
	&showUserHistory($opt{u});	
} elsif ($opt{d}) {
	&showDateHistory($opt{d});
} else {
	&usage("No options specified\n");
}

sub showUserHistory {
	($user, $date) = @_;
	chomp($date);

	# make sure the date format is right (for matching against system 'date' cmd):
	$date=~s/(\w+) (\d)$/$1  $2/;
	
	my $output="";
	my $line;
	my $header="${div}\nHistory for user $user:\n$div\n";
	
	$histfile="/home/$user/.history";
	open(FD, "$histfile") or ($opt{u} && print "${div}\nCouldn't open history file $histfile\n$div\n");

	while(<FD>){
		s/^#//;
		
		$histdate=`date -r $_`;
		chomp($histdate);
		# if this history command occurs on the date passed to us, 
		# or if we're just listing all commands for a user,
		# append the command history to the $output vbl:
		my $cmd=<FD>;
		if( ($histdate=~/$date/) || $opt{u} ){
			$output.=sprintf("%s %40s", $histdate, $cmd);
		}
	}
	
	# if there's anything in output, show it, otherwise print a msg:
	if($output){
		print $header.$output;
	} else {
		# only if single user, otherwise omit:
		$opt{u} && print "\n${div}\nNo history for user $user\n$div\n";
	}
}

sub showDateHistory{
	$date=shift;

	opendir(DH, "/home/");

	while(($user=readdir DH)){
		if($user ne "." && $user ne ".."){
			&showUserHistory($user, $date);
		}
	}
}

sub usage{
	$err && (print $err,"\n");
	die<<"~USAGE~";
Usage: $progname [-u <user>] [-d <date>] [-h]
       -h                     Display this help.

       -d <date>              Display shell history listing for all users on
                              date <date>.
                              Example: $progname -d "Oct 13"
                              Displays shell history listings for all users
                              who logged in on Oct 13 this year.

       -u <user>              Display complete shell history listing for 
                              the user <user>.
                              Example: $progname -u munk
                              Display a complete shell history listing for
                              the user 'munk'.
~USAGE~
}