gexpect

Gexpect

Gexpect is a pure golang expect-like module.

It makes it simple and safe to control other terminal applications.

It provides pexpect-like syntax for golang

child, err := gexpect.Spawn("python")
if err != nil {
	panic(err)
}
child.Expect(">>>")
child.SendLine("print 'Hello World'")
child.Interact()
child.Close()

It's fast, with its 'expect' function working off a variant of Knuth-Morris-Pratt on Standard Output/Error streams

It also provides interface functions that make it much simpler to work with subprocesses

child.Spawn("/bin/sh -c 'echo \"my complicated command\" | tee log | cat > log2'")

child.ReadLine() // ReadLine() (string, error)

child.ReadUntil(' ') // ReadUntil(delim byte) ([]byte, error)

child.SendLine("/bin/sh -c 'echo Hello World | tee foo'") //  SendLine(command string) (error)

child.Wait() // Wait() (error)

sender, reciever := child.AsyncInteractChannels() // AsyncInteractChannels() (chan string, chan string)
sender <- "echo Hello World\n" // Send to stdin

line, open := <- reciever // Recieve a line from stdout/stderr
// When the subprocess stops (e.g. with child.Close()) , receiver is closed
if open {
	fmt.Printf("Received %s", line)]
}

Free, MIT open source licenced, etc etc.

Check gexpect_test.go and the examples folder for full examples

Golang Dependencies

"github.com/kballard/go-shellquote"
"github.com/kr/pty"

Credits

KMP Algorithm: "http://blog.databigbang.com/searching-for-substrings-in-streams-a-slight-modification-of-the-knuth-morris-pratt-algorithm-in-haxe/"