AWK - Aho Weinberger Kernighan
AWK is an interpreted programming language designed for text processing and typically used as a data extraction and reporting tool.
It is a standard feature of most Unix-like operating systems. AWK was very popular in the late 1970s and 1980s, but from the 1990s has largely been replaced by Perl, on which AWK had a strong influence.
- Awk views a text file as records and fields.
- Like common programming language, Awk has variables, conditionals and loops.
- Awk has arithmetic and string operators.
- Awk can generate formatted reports
Syntax:
awk '/search pattern1/ {Actions}
/search pattern2/ {Actions}' file
In the above awk syntax:
- search pattern is a regular expression.
- Actions – statement(s) to be performed.
- several patterns and actions are possible in Awk.
- file – Input file.
- Single quotes around program is to avoid shell not to interpret any of its special characters.
$ cat employees.txt 100 Thomas Manager Sales $5,000 200 Jason Developer Technology $5,500 300 Sanjay Sysadmin Technology $7,000 400 Nisha Manager Marketing $9,500 500 Randy DBA Technology $6,000
$ awk '/n/ {print $2,$NF;}' employees.txt
Thomas $5,000 Jason $5,500 Sanjay $7,000 Nisha $9,500 Randy $6,000