BEGIN { printf "Initially, PROCINFO[\"FS\"] = %s\n", PROCINFO["FS"] FIELDWIDTHS = "3 4 5 6" printf "After assign to FIELDWIDTHS, PROCINFO[\"FS\"] = %s\n", PROCINFO["FS"] FS = FS printf "After assign to FS, PROCINFO[\"FS\"] = %s\n", PROCINFO["FS"] }