CODEWITHSUNDEEP
linuxnode.jsbashautocomplete
Krzysztof Wende
Krzysztof Wende

Reputation: 3247

Get bash autocompletion printed by stdin write

I want to write a program that will print out the autocompletions of bash.
Basically I'm writting something into bash stdin with

childProc.stdin.write("./myfi")

And would like to receive autocompletion for it like "./myfile.txt"

But childProc.stdout is empty after childProc.stdin.write("\t") so there has to be some other way to trigger autocompletion.

Any ideas?

Upvotes: 0

Views: 356

Answers (2)

Krzysztof Wende
Krzysztof Wende

Reputation: 3247

I've found an answer.
The thing that made it work was Pseudoterminal.
This module actually.
https://www.npmjs.com/package/pty.js-dl

Upvotes: 0

rici
rici

Reputation: 241771

Command-completion in only enabled in interactive shells. Bash is interactive if:

  • Neither a script filename nor the -c option were specified when invoking bash, and

  • both stdin and stderr are attached to terminals (as determined by isatty()), or

  • bash was started with the -i flag.

In your case, stdin is clearly a pipe, which is not a terminal. So probably command completion has been disabled. But if it were enabled, you'd see the result on stderr not stdout.

So you could try supplying the -i command line option when starting your bash shell, or you could attach its stdin, stdout and stderr file descriptors to a pseudo-tty. In either case, what you will see coming back from bash will be intermingled with terminal control codes, so you'll probably want to set TERM to something basic (like dumb).

If you want to see the completions which bash might generate, you can use the compgen built-in. compgen does not know about the customized completion settings installed by the complete command, and it is not easy to get the environment set up correctly for the -F and -C function, but other than that you can probably get it to generate whatever completion lists you would like. See the Bash manual for detailed option documentation.

Upvotes: 2

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