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The command-line arguments are available to an awk program: the array ARGV contains the elements ARGV[0], . . ., ARGV[ARGC-1]; as in C, ARGC is the count. ARGV[0] is the name of the program (generally awk); the remaining arguments are whatever was provided (excluding the program and any optional arguments) when awk is invoked. The following command line contains an awk program that echoes the arguments that appear after the program name:
awk '
BEGIN {
for (i = 1; i < ARGC; i++)
printf "%s ", ARGV[i]
printf "\n"
}' $
The arguments may be modified or added to;
ARGC
may be altered.
As each input file ends,
awk
treats the next non-null element of
ARGV
(up to the current value of
ARGC-1)
as the name of the next input file.
One exception to the rule that an argument
is a filename is when
it is in the form
var=value
Then the variable var is set to the value value, as if by assignment. Such an argument is not treated like a filename. If value is a string, no quotes are needed.
A better way to initialize an awk variable on the command line is to use the -v option (-vvar=value) since there is no ambiguity.