如何从C程序调用bash shell脚本中定义的函数

Question

I have

    #!/bin/sh

    func1()
    {
        echo "This is func1 from shell script"
    }

    func2()
    {
        echo "This is func2 from shell script"

    }

I want to call func1 and func2 from a C program. Can I do that ?

Answer 1

This is unlikely to be a good idea, but I suppose you could write something like this:

if (! fork()) { // TODO fork can return -1 on error; should check for that
    execl("/bin/sh", "-c", ". FILE && func1", (char *)NULL);
    // TODO should check to make sure execlp successfully replaced the process
}

where FILE is the name of the .sh file that defines func1 . The above will spawn a child process, and replace that child process with an instance of Bash (or whatever your shell is) with the arguments -c (meaning "the script to run is the next argument") and . FILE && func1 . FILE && func1 (which is the script; it means "run the commands in FILE , and if that succeeds, then run the command func1 ").

For more information:

• about fork
• about execl
• about .

Answer 2

A little simpler than using fork / exec is the stdlib "system" command.

See man 3 system .

Assume your bash functions are in file "/tmp/scripts.sh" ...

system("bash -c \". /tmp/scripts.sh ; func1 ; func2\"");

Answer 3

如果要获取执行脚本的退出代码，则应使用system，否则使用vfork + exec *