GoAWK: an AWK interpreter written in Go

GoAWK: an AWK interpreter written in Go

AWK is a fascinating text-processing language, and somehow after reading the delightfully-terse The AWK Programming Language I was inspired to write an interpreter for it in Go. So here it is, pretty much feature-complete and tested against "the one true AWK" test suite.

To use the command-line version, simply use go get to install it, and then run it using goawk:

$ go get github.com/benhoyt/goawk
$ goawk 'BEGIN { print "foo", 42 }'
foo 42
$ echo 1 2 3 | goawk '{ print $1 + $3 }'
4

To use it in your Go programs, you can call interp.Exec() directly for simple needs:

input := bytes.NewReader([]byte("foo bar\n\nbaz buz"))
err := interp.Exec("$0 { print $1 }", " ", input, nil)
if err != nil {
    fmt.Println(err)
    return
}
// Output:
// foo
// baz

Or you can use the parser module and then interp.New() and Interp.Exec() to control execution, set variables, etc:

src := "{ print $1+$2 }"
input := "1,2\n3,4\n5,6"

prog, err := parser.ParseProgram([]byte(src))
if err != nil {
    fmt.Println(err)
    return
}
p := interp.New(nil, nil)
p.SetVar("FS", ",")
err = p.Exec(prog, bytes.NewReader([]byte(input)), nil)
if err != nil {
    fmt.Println(err)
    return
}
// Output:
// 3
// 7
// 11

Have fun, and please contact me if you're using GoAWK or have any feedback!