I want to write an awk script file using the #!/bin/awk -f header, but I want this script to always use : as a field separator. But for some reason writing #!/bin.awk -F: -f gives me a syntax error. I also want this script to always run on the same file, so I'd like to hardcode that as well. Basically, what I want to work is this:
#!/bin/awk -F: -f -- /etc/passwd
followed by some awk code
Many systems allow only a single argument in a shebang line, so everything after the space is passed as one argument.
However, you can set FS and even ARGV in your script's BEGIN block, like this:
#!/bin/awk -f # using the #!/bin/awk -f
BEGIN {
FS=":" # always use : as a field separator
ARGC=2
ARGV[1]="/etc/passwd" # always run on the same file
}
$3==0 { # followed by some awk code
print $1
}
Run it:
$ chmod u+x program.awk
$ ./program.awk
root