#!/bin/ksh
# @(#) httpmon.ksh 1.1.1 97/07/18
# 95/04/08 john h. dubois iii (john@armory.com)
# 95/07/17 Do stty sane in case tty is not already set up.
# 95/07/30 Added all options, use of default file.
# 96/02/06 Understand new logfile format.
# 96/03/06 Use gawk instead of awk.  Some bad requests result in enough fields
#          in a record to make awk die.
# 96/03/11 exec monitor procs.
# 96/03/16 Do not print control characters.
# 97/07/18 1.1.1 Changed default file & output to standard input & output;
#          removed default logfile owner.

function mon {
    # Must open tty separately for reading & writing
    if [ -n "$MONTTY" ]; then
	exec < "$MONTTY" > "$MONTTY"
	stty sane
	$Debug && print "$name: Testing output to monitor tty $MONTTY"
    fi
    if $Debug && [ $# -eq 1 ]; then
	l -- "$1" >&2
	print -u2 "Monitoring $1"
    fi
    exec tail -f "$@" | exec gawk -v Pat="$SO_PATTERN" -v Debug=$Debug '
    BEGIN {
	# Adding " to FS is cheaper than parsing correctly, and this
	# does not have to be perfect.
	FS = "[ \t\"]+"
	Debug = Debug == "true"
	if (Pat != "") {
	    cmd = "tput rev"
	    cmd | getline rev
	    close(cmd)
	    cmd = "tput rmso"
	    cmd | getline unrev
	    close(cmd)
	}
    }
    NR == 1 {
	if ($2 ~ /^\[/) {
	    actF = 7
	    objF = 8
	}
	else {
	    actF = 6
	    objF = 7
	}
    }
    {
	if (Debug)
	    print "Read: " $0 > "/dev/stderr"
	if (Pat != "" && $objF ~ Pat) {
	    printf "%s",rev
	    DoUnrev = 1
	}
	# Print source host, action, and object
	# Do not print a newline until after unrev
	printf "%-30s %s %s",NoCtl($1),NoCtl($actF),NoCtl($objF)
	if (DoUnrev) {
	    printf "%s\n",unrev
	    DoUnrev = 0
	}
	else
	    print ""
    }
    function NoCtl(S) {
	gsub(/[^ -~]/,"?",S)
	return S
    }
    '
}

name=${0##*/}
Usage=\
"Usage: $name [-hx] [-t<tty>] [-o<logfile-owner>] [-s<standout-pat>] [logfile]"
MONTTY=
LOGFILE=
LOGOWNER=
SO_PATTERN=
defaultFile=/etc/default/httpmon
Debug=false
PATH=$PATH:/usr/local/bin	# for gawk
oTERM=$TERM
export TERM=

# Build help message here so it will get default var values.
help="$name: monitor HTTP requests.
$name monitors an HTTP request logfile.  As records are added to the logfile
by the HTTP daemon, the remote hostname and HTTP request are printed.
$Usage
If [logfile] is not given, the standard input is read.
Options:
-h: Print this help.
-x: Turn on debugging.
-t<tty>: Send output to <tty> instead of the standard output.
-y<termtype>: Set the monitor tty terminal type to be <termtype> instead of
    getting it from the TERM environment variable or, if -t is used, the
    /etc/ttytype terminal type database.  A terminal type is only needed if a
    standout pattern is used.
-o<logfile-owner>: If the logfile does not exist, create it with ownership
    of <logfile-owner>.  If the logfile-owner is not set, $name will abort
    if the logfile does not exist.
-s<standout-pattern>: URLs that match the given pattern will be displayed in
    standout, if the display is capable of it.  By default, nothing is
    displayed in standout.
The logfile, monitor tty, logfile owner, standout pattern, and monitor tty
terminal type can be set by assigning values to LOGFILE, MONTTY, and LOGOWNER,
SO_PATTERN, and TERM in the file $defaultFile, in the form e.g.:

SO_PATTERN='^/~(john|spcecdt|pax|zenomt)/'
MONTTY=/dev/tty10
LOGFILE=/usr/local/lib/httpd/logs/access_log
LOGOWNER=spinner

Arguments given on the command line will override values assigned in the
default file."

[ -f "$defaultFile" ] && . "$defaultFile"

while getopts :hxt:o:s:y: opt; do
    case $opt in
    h)
	echo "$help"
	exit 0
	;;
    x)
	Debug=true
	;;
    o)
	LOGOWNER=$OPTARG
	;;
    t)
	MONTTY=$OPTARG
	;;
    y)
	TERM=$OPTARG
	;;
    s)
	SO_PATTERN=$OPTARG
	;;
    +?)
	print -u2 "$name: options should not be preceded by a '+'."
	exit 1
	;;
    :)
        print -r -u2 -- \
        "$name: Option '$OPTARG' requires a value.  Use -h for help."
        exit 1
        ;;
    ?)
	print -u2 "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done

# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

case $# in
0) 
    ;;
1) LOGFILE=$1
    ;;
*)
    print -u2 "$Usage\nUse -h for help."
    exit 1
    ;;
esac

if [ -n "$MONTTY" ]; then
    MONTTY=${MONTTY##/dev/}
    if [ -n "$SO_PATTERN" -a -z "$TERM" ]; then
	set -- $(egrep "[ 	]+$MONTTY[ 	]*\$" /etc/ttytype)
	TERM=$1
	if [ -z "$TERM" ]; then
	    print -u2 \
"$name: Warning: No termtype for tty $MONTTY found in /etc/ttytype;
no standout will be used."
	    unset SO_PATTERN
	fi
    fi
    [[ "$MONTTY" != */* ]] && MONTTY=/dev/$MONTTY
elif [ -n "$SO_PATTERN" -a -z "$TERM" ]; then
    if [ -n "$oTERM" ]; then
	TERM=$oTERM
    else
	print -u2 \
    "$name: Warning: TERM not set and -t not given; no standout will be used."
	unset SO_PATTERN
    fi
fi
export TERM

$Debug && print -u2 \
"LOGFILE=$LOGFILE
LOGOWNER=$LOGOWNER
MONTTY=$MONTTY
SO_PATTERN=$SO_PATTERN
TERM=$TERM"

if [ -n "$LOGFILE" -a ! -a "$LOGFILE" ]; then	# Recreate it if neccessary
    if [ -n "$LOGOWNER" ]; then
	$Debug && print -u2 "logfile did not exist; creating it..."
	touch "$LOGFILE" &&
	chown "$LOGOWNER" "$LOGFILE" &&
	chmod a+r "$LOGFILE" || {
	    print -ru2 -- \
"$name: Could not create/chown/chmod logfile $LOGFILE; aborting."
	    exit 1
	}
    else
	print -ru2 -- "$name: logfile $LOGFILE does not exist; aborting."
	exit 1
    fi
fi
[ -n "$LOGFILE" ] && mon "$LOGFILE" || mon