32 lines
No EOL
1.7 KiB
Text
32 lines
No EOL
1.7 KiB
Text
{{language
|
|
|exec=interpreted
|
|
|tag=awk
|
|
}}{{CompileOnline}}
|
|
AWK is a small but powerful programming language that can process and convert text files. AWK is part of every [[Unix]]-derived system.
|
|
|
|
Each AWK program consists of pattern-action statements.
|
|
The program reads each input line, checks lines against patterns, and runs matching actions.
|
|
For programs that never read input lines, the entire program can be one <code>BEGIN { ... }</code> block.
|
|
|
|
* ''List users who have /bin/ksh as a shell.''<syntaxhighlight lang="awk">$ awk -F: '$7 == "/bin/ksh" { print $1 }' /etc/passwd</syntaxhighlight>
|
|
|
|
AWK has only three types of variables: they are strings, floating-point numbers, and associative arrays (where every array index is a string).
|
|
Conversion between strings and numbers is automatic. AWK also has regular expressions, which appear in many AWK programs.
|
|
There are a few built-in functions, like cos() and sprintf().
|
|
|
|
* ''Find average line length.''<syntaxhighlight lang="awk">$ awk '{ cnt += length($0) } END { print cnt / NR }' /etc/rc</syntaxhighlight>
|
|
|
|
The name "AWK" comes from the initials of Alfred Aho, Peter Weinberger and Brian Kernighan: they invented AWK during the 1970s.
|
|
A few decades later, Kernighan continues to maintain the [[nawk|reference implementation]] of AWK.
|
|
|
|
==Links==
|
|
*[http://leaf.dragonflybsd.org/cgi/web-man?command=awk§ion=1 awk(1) manual page], short and brief
|
|
*[https://www.gnu.org/software/gawk/ gawk] GNU awk [https://www.gnu.org/software/gawk/manual/ manual]
|
|
*[[wp:AWK (programming language)|AWK in Wikipedia]]
|
|
*[http://awk.info AWK Community Portal]
|
|
|
|
==Online-Execution==
|
|
* [https://ideone.com ideone.com] - gawk, mawk (both are kept up to date)
|
|
|
|
==Todo==
|
|
[[Tasks_not_implemented_in_AWK]] |