Linux Shells by Example

awk (gawk)—pattern scanning and processing language

gawk [ POSIX or Gnu style options ]  –f program–file [ - ] file…

awk scans each input filename for lines that match any of a set of patterns specified in prog. (See Chapter 5, "The gawk Utility: gawk as a Linux Tool." ) In the following example, use awk, nawk, or gawk, depending on your version of awk.

Example A.4.

1 awk '{print $1, $2}' file 2 awk '/John/{print $3, $4}' file 3 awk -F: '{print $3}' /etc/passwd 4 date | awk '{print $6}'

Explanation

1. Prints the first two fields of file where fields are separated by white space.

2. Prints fields 3 and 4 if the pattern John is found.

3. Using a colon as the field separator, prints the third field of the /etc/passwd file.

4. Sends the output of the ...