AWK

{{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 BEGIN { ... } block.

''List users who have /bin/ksh as a shell.''

$ awk -F: '$7 == "/bin/ksh" { print $1 }' /etc/passwd

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.''

$ awk '{ cnt += length($0) } END { print cnt / NR }' /etc/rc

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&section=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==

[http://ideone.com ideone.com] - gawk, mawk (both are kept up to date)

==Todo== [[Reports:Tasks_not_implemented_in_AWK]]