show

#!/bin/sh
##
## Shows colorized log
## Copyright (c) 2006 by Marcin Hłybin
##                       Michal Nazareicz (mina86/AT/mina86.com)
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
## This is part of Tiny Applications Collection
##   -> http://tinyapps.sourceforge.net/
##

set -e


##
## Default variables
##
SHOWLINES="${SHOWLINES:-50}"
SHOWPAGER="${SHOWPAGER:-less -r}"
if [ -z "$SHOWCOLOR" ]; then
	if which ccze >/dev/null 2>&1
	then SHOWCOLOR="ccze -A"
	else SHOWCOLOR=cat
	fi
fi
SHOWLOGDIRS=":${SHOWLOGDIRS-/var/log}"
SHOWLOGEXTS=":${SHOWLOGEXTS-.log}"

ARG0="${0##*/}"


##
## Searches for log file
##
log_file () {
	__OIFS="$IFS"
	IFS=:
	for __D in $SHOWLOGDIRS; do
		for __E in $SHOWLOGEXTS; do
			[ -r "$__D/$1$__E" ] || continue
			FILE="$__D/$1$__E"
			IFS="$__OIFS"
			return 0
		done
	done
	echo "$ARG0: $1: no such file" >&2
	exit 1
}


##
## Cheks number of arguments
##
check_args () {
	__NUM="$1"
	while [ $# -ne 1 ]; do
		shift
		if [ $__NUM -eq "$1" ]; then return 0; fi
	done
	echo "$ARG0: wrong number of arguments; type 'show --help' for help" >&2
	exit 1
}


##
## Usage
##
if [ $# -eq 0 ] || [ X"$1" = X--help ] || [ "X$1" = X-h ]; then
	cat << EOF
usage: $ARG0 [ s | show ] [ <lines> ] <file>   displayes <file>
       $ARG0 ( f | find ) <pattern> <file>     greps <pattern> from <file>
       $ARG0 ( l | list )                      lists log files in /var/log

sexamples: $ARG0 f ahes auth.log
           $ARG0 l
           $ARG0 /var/log/httpd/access.log
           $ARG0 500 /var/log/messages
EOF


##
## Find
##
elif [ X"$1" = Xf ] || [ X"$1" = Xfind ]; then
	check_args $# 3
	log_file "$3"
	grep "$2" -- "$FILE" | $SHOWCOLOR | $SHOWPAGER


##
## List
##
elif [ X"$1" = Xl ] || [ X"$1" = Xlist ]; then
	check_args $# 1
	OIFS="$IFS"
	IFS=:
	for DIR in $SHOWLOGDIRS; do
		[ -n "$DIR" ] && [ X"$DIR" != X. ] && [ X"$DIR" != X.. ] || continue
		cd "$DIR" || continue
		echo "-------------------- $DIR --------------------"
		find . -type f \! -name '*.gz' \! -name '*.[0-9]' | \
			cut -d/ -f2- | sort | ${PAGER:-less}
		cd -
	done
	IFS="$OIFS"


##
## Show
##
else
	if [ X"$1" = Xs ] || [ X"$1" = Xshow ]; then shift; fi
	check_args $# 1 2

	if [ $# -eq 2 ]; then
		SHOWLINES="$1"
		shift
	fi

	log_file "$1"
	if [ X"$SHOWCOLOR" = Xcat ] || [ X"$SHOWCOLOR" = X'cat -s' ]; then
		NUM=$(( $(wc -l <"$FILE") - $SHOWLINES ))
		[ $NUM -gt 1 ] || NUM=1
		$SHOWCOLOR <"$FILE" | $SHOWPAGER +$NUM
	else
		tail -n "$SHOWLINES" <"$FILE" | $SHOWCOLOR | $SHOWPAGER
	fi
fi