awk example - add a string at the begginning of the each line

Add 127.0.0.1 at the beginning of the each line:

cat /etc/passwd | awk '{ print "127.0.0.1 " $1 }'

The output will be:

127.0.0.1 root:x:0:0:root:/root:/bin/bash
127.0.0.1 daemon:x:1:1:daemon:/usr/sbin:/bin/sh
127.0.0.1 bin:x:2:2:bin:/bin:/bin/sh
127.0.0.1 sys:x:3:3:sys:/dev:/bin/sh
127.0.0.1 sync:x:4:65534:sync:/bin:/bin/sync
127.0.0.1 games:x:5:60:games:/usr/games:/bin/sh
...