This is a little bash script I use to quickly check the syntax on a directory of PHP files.

output.txt

jmhobbs@Cordelia:/data/working/example$ (193m|master|?AM)$ phlint
= Checking 176 files with 4 processes...
(1) = 50
(2) = 100
(3) = 150
(1) Done
(0) Done
(3) Done
(2) Done
jmhobbs@Cordelia:/data/working/example$ (193m|master|?AM)$

phlint.sh

#!/bin/bash

# Multi-processor version for faster checks!

checkfiles () {
	I=$2
	for file in $1; do
		php -l $file > /dev/null
		I=$(($I+1))
		OFFSET=$(($I%50))
		if [ "$OFFSET" == "0" ]; then
			echo "($3) = $I"
		fi
	done
	echo "($3) Done"
}

TOTAL=$(find . -iname '*.php' | wc -l)
PROCS=$(cat /proc/cpuinfo | grep 'cpu cores' | head -n 1 | awk '{print $4}')

echo "= Checking $TOTAL files with $PROCS processes..."

# This is a bit brute force, but it works
BLOCKSIZE=$(($TOTAL / $PROCS))
ASSIGNED=0
for PROC in $(seq 0 $(($PROCS - 1 ))); do
	STARTINGPOINT=$ASSIGNED
	if [ "$(($PROC + 1))" == "$PROCS" ]; then
		FILES=$(find . -iname '*.php' | head -n -$ASSIGNED)
		THISBLOCK=$(find . -iname '*.php' | head -n -$ASSIGNED | wc -l)
		ASSIGNED=$(($ASSIGNED + $THISBLOCK))
	else
		OFFSET=$((($PROC + 1) * $BLOCKSIZE))
		FILES=$(find . -iname '*.php' | head -n $OFFSET | tail -n $BLOCKSIZE)
		THISBLOCK=$(find . -iname '*.php' | head -n $OFFSET | tail -n $BLOCKSIZE | wc -l)
		ASSIGNED=$(($ASSIGNED + $THISBLOCK))
	fi;
	( checkfiles "$FILES" $STARTINGPOINT $PROC ) &
done

# Wait on the sub-shells
while true; do
	ALIVE=$(ps -ef | grep $$ | grep -v grep | grep -v 'ps -ef' | wc -l)
	# This is 2 instead of 1 because the $() counts as a sub-shell
	if [ "2" == "$ALIVE" ]; then
		break;
	else
		sleep 1
	fi
done

echo "= Done"