awk script language for text operation

I was looking for fileAPI today. then found blog post that it is write about text operation using javascript and fileAPI.
This page introduces how to rewrite contents( in file. after complete to read contents, it would rewrote by javascript's regular expression.
and there are posted comment follow this.

hey! it can do by awk!
awk? I do not know it.
what is awk, google back to me result in list.
↓very kindness page.

awk is script language what it has feature text operation. It has statement looks like C language and can write too short!
It is installed in Linux or UNIX from beginning.
awk treats one line as array. show example,

# cat somedata

1 2 3
4 5 6
7 8 9

# awk '{print $1}' somedata


It is useful and easy. You can get all you need value using control statement and regular expression in awk.
perl is inspired by it.
awk seems give influence to other language early point of one liner and regular expression.