Bash重定向和标准输入

Question

I'm hoping this is a quick question for a guru. I have the following command which works great from the command line:

 src/protected/yiic shell src/index.php <<< createmvp < /dev/tty

This command executes the yiic bash script and passes it the arguments shell and src/index.php.

The first <<< passes the argument createmvp to the terminal prompt which is displayed when yiic shell src/index.php is run on it's own.

The second < then allows std in to be returned to the application.

However when I run this inside a bash script

#!/bin/bash
src/protected/yiic shell src/index.php <<< createmvp < /dev/tty

The script doesn't pass createmvp into the shell. If I remove the < /dev/tty bit passing createmvp works, but then recapture the terminal obviously doesn't. Nothing I seem to do works.

while(!isset($input))
{
    $input = trim(fgets(STDIN));
    if(!$input)
        echo "$configVar can not be NULL";
}

Any ideas, on how to make this work as it does from the command line?

Thanks in advance

Alan

Answer 1

(echo createmvp; cat /dev/tty) | src/protected/yiic shell src/index.php

I think that the reason <<< createmvp < /dev/tty doesn't work is because both <<< and < are ways to specify the source for standard in and you can't do both. <<< takes a string as an argument and passes it to stdin whereas < takes a file.

Answer 2

I think you should use eval:

#!/bin/bash
cmd="src/protected/yiic shell src/index.php <<< createmvp < /dev/tty"
eval $cmd

Answer 3

To exit the script as soon as yiic processes the exit command itself, a trap on exit can be used for the yiic subshell:

# small addition to cpugeniusmv's answer
(echo createmvp; cat /dev/tty) | 
    (trap 'kill 0' EXIT; src/protected/yiic shell src/index.php)