Linux Shell Scripting Cookbook - Third Edition

Reading the command output from awk

Awk can invoke a command and read the output. Place a command string within quotes and use the vertical bar to pipe the output to getline:

    "command" | getline output ;

The following code reads a single line from /etc/passwd and displays the login name and home folder. It resets the field separator to a : in the BEGIN block and invokes grep in the main block.

    $ awk 'BEGIN {FS=":"} { "grep root /etc/passwd" | getline; \
        print $1,$6 }'
    root /root