#!/bin/shgawk -v app=$3 -v out=$4 'BEGIN {  FS = " ";  if ((app != "") && (out != "")) {    getline dflt < app;    while ((getline < app) > 0)      base[$1] = $2;  }  FS = ",";}(NR == 1) {  for (i = 0; ++i <= NF; )    items[i] = $i;}(NR > 1) {  for (i = k = 0; ++i <= NF; ) {    if (k++ > 0) printf(" ");    item = (items[i] "=" $i);    printf("%s", item);    if (items[i] in base) apps[item] = base[items[i]];    else                  apps[item] = dflt;  }  printf("\n");}END {  if (out != "") {    print dflt > out;    for (t in apps)      if (apps[t] != dflt)        printf("%s %s\n", t, apps[t]) > out;  }}' $1 > $2