#!/bin/sh
#
# Apache log helper.
#
# Copyright (c) 2004 Lorance Stinson <lorance@worldpbx.com>

# Configuration section.
# Directory that log files reside in.
logdir="/var/log/httpd/"
# Pattern to exclude local hosts. Used with egrep.
localip="111\.222\.333\.444|192\.168\.[0-9]*\.[0-9]*|127\.0\.0\.1"
# The default log file.
logfile="access_log"
# The alternate log files.
altloga="error_log"
altlogb="referer_log"
# The extension for the previous version.
prevext=".0"
# The name of this program.
myname="`basename $0`"
# Command to cat the log file.
catcmd="cat"
# The default grep command.
grepcmd="grep"

#**************************************************************************
# usage
#**************************************************************************
usage(){
    cat<<EOHELP
Usage: $myname [OPTION]... [PATTERN(S)]
Apache Log Helper.  View/search Apache log files.
The log file is grepped for PATTERN(s) if specified.
By default log files are looked for in $logdir.

-a          Use the alternate log file $altloga.
-A          Use the alternate log file $altlogb.
-c          Print only the number of lines matched.
-d          Print the command(s) that would execute. (Debug)
-e          Exclude local IP addresses.
-E          Use egrep in place of grep.
-f <file>   Obtain patterns from <file>. 
-F          Use fgrep in place of grep.
-h          Print this help text and exit.
-i          Ignore case on all matches.
-l <file>   Use <file> in place of $logfile.
-n <lines>  Output <lines> lines when using -t.
-o          Use previous version of log file. Eg. $logfile$prevext
-p          Send output to \$PAGER or more.
-t          Send the output to tail.
-x <filter> Filter the output with the inverted pattern <filter>.
-X <file>   Same as -x but obtain patterns from <file>.
EOHELP
    exit $1
}

#**************************************************************************
# Parse the command line arguments.
#**************************************************************************

# Process the command line arguments.
args=`getopt "aAcdeEf:Fhil:n:optx:X:" "$@" 2>&1`
if [ $? != 0 ] ; then
    # Fix the error message.
    # Change getopt to $myname and remove any trailing --.
    echo $args | sed "s/getopt/$myname/;s/\s*--\s*$//"
    # Print help and exit.
    echo
    usage 1
fi
eval set -- "$args"

# First pass.
args=""
while true ; do
    case "$1" in
        # Use the log file $altloga.
        -a) logfile=$altloga ; shift ;;
        # Use the log file $altloga.
        -A) logfile=$altlogb ; shift ;;
        # Final count only.
        -c) pager="wc -l" ; shift ;;
        # Debug. Print command(s).
        -d) debug=1 ; shift ;;
        # Exclude local IP Addresses.
        -e) filter="| egrep -v '$localip'" ; shift ;;
        # Use egrep in place of grep.
        -E) grepcmd="egrep" ; shift ;;
        # Use egrep in place of grep.
        -F) grepcmd="fgrep" ; shift ;;
        # Print the help text.
        -h) usage 1 ;;
        # Ignore case.
        -i) ignorecase="-i" ; shift ;;
        # Use a different log file.
        -l) if [ -r "$logdir$2" ] ; then
                logfile=$2
            elif [ -r "$2" ] ; then
                logfile=$2
                logdir=""
            else
                echo "Could not find the log file \"$2\"."
                exit 1
            fi
            shift 2 ;;
        # The number of lines to output with tail.
        -n) lines=" -n $2" ; shift 2 ;;
        # Send the final output to a pager.
        -p) if [ "$PAGER" ] ; then
                pager="$PAGER"
            else
                pager="more"
            fi
            shift;;
        # End of arguments and start of search patterns.
        --) for nextarg  ; do
                args="$args $nextarg"
            done
            break ;;
        # Unknown or used in the next pass.
        *) args="$args $1";
            shift ;;
    esac
done

if [ $ignorecase ] ; then
    grepcmd="$grepcmd $ignorecase"
fi

# Second pass.
# These can be are affected by the previous set.
eval set -- "$args"
while true ; do
    case "$1" in
        # Obtain patterns from a file.
        -f) if [ -r "$2" ] ; then
                filter="$filter | $grepcmd -f $2"
            else
                echo "Could not find the pattern file \"$2\"."
                exit 1
            fi
            shift 2 ;;
        # Previous version of log file.
        -o) logfile="$logfile$prevext"
            if [ ! -r "$logdir$logfile" ] ; then
                echo "Could not find the log file \"$logdir$logfile\"."
                exit 1
            fi
            shift ;;
        # Send the final output to tail.
        -t) pager="tail$lines" ; shift ;;
        # Filter the output with a pattern using grep.
        -x) filter="$filter | $grepcmd -v $2" ; shift 2 ;;
        # Obtain inverted patterns from a file.
        -X) if [ -r "$2" ] ; then
                filter="$filter | $grepcmd -vf $2"
            else
                echo "Could not find the pattern file \"$2\"."
                exit 1
            fi
            shift 2 ;;
        # End of arguments and start of search patterns.
        --) shift ; break ;;
        # Invalid argument.
        *) echo "Invalid option $1"
           usage 1;;
    esac
done

#**************************************************************************
# Create the command to be evaluated.
#**************************************************************************

# If there is a pattern use grep instead of cat.
if [ "$1" ] ; then
        catcmd="$grepcmd \"$1\""

    # Are there more patterns?
    shift
    if [ "$1" ] ; then
        moregrep=""
        for pattern ; do
            moregrep="$moregrep | $grepcmd \"$pattern\""
        done
    fi
elif [ "$pager" -a  ! "$filter" ] ; then
    # Special case. The user just wants to use the pager.
    command="$pager $logdir$logfile"
fi

# Build the command, unless the special case was chosen.
if [ ! "$command" ] ; then
    command="$catcmd $logdir$logfile $moregrep $filter"

    if [ "$pager" ] ; then
        command="$command | $pager"
    fi
fi

#**************************************************************************
# Run the command.
#**************************************************************************

# Is debug set?
if [ $debug ] ; then
    # Print the command.
    echo $command
else
    # Execute the command.
    eval $command
fi