Jawk
Jawk is a pure Java implementation of AWK. You can run it as a CLI, embed it directly in Java applications, compile scripts once and reuse them, evaluate AWK expressions, feed it structured input, expose your own Java functions as extensions, and enable a sandboxed runtime when you need tighter execution constraints.
Support for POSIX AWK and Gawk
Jawk fully implements POSIX AWK, and adds support for the most commonly used gawk-specific features:
- Builtins, available by default through the built-in GNU Awk compatibility extension:
asort(), asorti(), typeof(), isarray(), mkbool(), gensub(), patsplit(), strtonum(), systime(), mktime(), strftime(), the gettext functions, and PROCINFO["sorted_in"]-controlled array traversal
- Arrays of arrays (
a[i][j]), with gawk's runtime typing rules, and typed regexp literals (@/re/)
- Source inclusion with
@include, namespaces with @namespace and ns::name, and indirect function calls such as @functionName(args)
- The
BEGINFILE / ENDFILE special patterns and the nextfile statement, with the ERRNO and ARGIND special variables, so a script can hook into the command-line file processing loop and skip unreadable files without a fatal error
- The
IGNORECASE, SYMTAB, and FUNCTAB special variables
- The
/dev/stdout, /dev/stderr, and /dev/stdin special filenames in redirections and getline, plus /dev/null on Windows
The gawk-specific @ syntax and arrays-of-arrays syntax are rejected in --posix mode.
See the compatibility page for detailed behavior notes and live compatibility reports against the POSIX, One True Awk, and gawk test suites.
Installation
Install the jawk command with one line; the launcher finds a Java runtime (Java 8 or later) automatically:
curl -fsSL https://jawk.io/get | sh
On Windows (PowerShell):
irm https://jawk.io/get.ps1 | iex
See the installation page for details, Maven/Gradle coordinates, and the standalone jar.
CLI Example
echo "hello world" | jawk '{ print $2 ", " $1 "!" }'
The CLI follows the POSIX argument conventions, and passes unknown options on to the script through ARGV once the program text has been supplied, as gawk does, which makes #! interpreter scripts work. See the CLI documentation for details.
Java Example
Awk awk = new Awk();
String result = awk.script("{ print toupper($0) }").input("hello world").execute();
The variables passed to an embedded script may be Map and List trees, so JSON-like structures can be traversed with plain AWK array syntax. See the Java documentation for details.
Documentation
Contributing
See CONTRIBUTING.md.
