Process Monitoring Bash Script

monitoring.sh

#!/bin/bash

CMDS="php-fpm nginx memcached php java beam.smp|epmd"
OUTFILE=$(tty)

cmd_values=()
cmd_prev_value=""

function get_stats()
{
    awk 'BEGIN {
             split("'$cmd_prev_value'", prev, /,/)
	     sum_exec=0; iowait_sum=0; rss=0
         }
         
         /^se.sum_exec_runtime/   {sum_exec+=$3}
         /^se.iowait_sum/   {iowait_sum+=$3}
         
         /^VmRSS/           {rss+=$2}
         
         END {
	     CONVFMT="%.10g"
             printf(" %s %s %s kB", sum_exec-prev[1], iowait_sum-prev[2], rss) >> "'$OUTFILE'"
             printf("%s,%s", sum_exec, iowait_sum)
         }' \
    $(eval echo /proc/{$1}/{task/*/sched,status} | tr -d '{}')
}

function get_cpu_stat()
{
    #     USER_HZ
    #     user    user nice system  idle     iowait irq  softirq steal guest
    #cpu  403898  50        532159  12154737 16497  2274 77612   0     0
    awk '/cpu / {
            CONVFMT="%.10g"
            printf(" %s %s %s %s %s %s %s %s %s", $2, $3, $4, $5, $6, $7, $8, $9, $10) >> "'$OUTFILE'"
        }' /proc/stat
}

cmd_num=0

function stat_line()
{
    echo -n $(date +'%Y-%m-%d %H:%M:%S.%N') >> $OUTFILE
    get_cpu_stat
    cmd_num=0
    for cmd in $CMDS; do
        echo -n " $cmd"
        cmd_prev_value=${cmd_values[cmd_num]}
        cmd_values[$cmd_num]=$(get_stats $(pgrep -xd , $cmd))
        ((cmd_num++))
    done
    echo >> $OUTFILE
}

for cmd in $CMDS; do
    cmd_values[$cmd_num]=0,0
    ((cmd_num++))
done

while [[ 1 ]]; do
    stat_line
    sleep .9 
done