Awk control files

Just as with sed, we can simplify the command line by creating and including control files. This also makes the later editing of the command more easily achievable. The control files contain all the statements that we want awk to execute. The main thing that we must consider with sed, awk, and, shell scripts is modularization; creating reusable elements that can be used to isolate and reuse the codes. This saves us time and work and we get more time for the tasks that we enjoy.

To see an example of an awk control file, we should revisit the formatting of the passwd file. Creating the following file will encapsulate the awk statements:

function green(s) {
    printf "\033[1;32m" s "\033[0m\n"
}
BEGIN {
    FS=":"
    green("   Name:   UID:       Shell:")
}
{
    printf "%10s %4d %17s\n",$1,$3,$7
}

We can save this file as passwd.awk.

Being able to encompass all the awk statements in the one file is very convenient and the execution...