#! /bin/awk -f
#
#<ABS># Explore Lesser Known Features of AWK.
#
#<DSC>Features explored
# * Array variables and the command line
#
# * opening standard input from within the script.
#
# * discard arbitrary fields from a record
#
#<CPY># PD 2004 Manfred Waßmann http://www.berlinos.de/
#<END>#
#
#
#

BEGIN{
	# Set (additional) variables as if they were geiven on the command line
	ARGV[ARGC++]="t=42";
	# This does NOT work for arrays:
	# # ARGV[ARGC++]="A[1]=42";
	# # ARGV[ARGC++]="A=42"; # only because A is referenced as an array in END

	# Open stdin from within the script
	filename="elk.awk.input"
	ARGV[ARGC++]=filename;

	# create the file to be read
	system("ps ax >elk.awk.input");
}

/elk.awk/{
	print"Read line:\n"$0;
	# print matched line except second, third and fourth field
	$2=$3=$4="";print"mangled: "$0;
}

END{
	# Output variables from the command line
	print"t = "t;
	for(i in A){print"A["i"] = "A[i];}

	# Clean up unless -vkeep=1 was given on the command line
	if(!keep){system("rm -f "filename);}
}