如何在传递字符串值并接受/存储它作为输出返回的字符串的同时从 python 执行用 C 编写的文件。 (Linux)

Question

I have tried the subprocess module but providing the main function of C with string values but it doesn't seem to work for me. There are certain solutions available on the web but I'm having difficulty in understanding and implementing them. Any help will be appreciated.

I want to execute a file written in C passing it arguments from my pyhthon code and after that C file is executed I want to capture what it returns in my python code.

const char* main(int argc , char* argv[]) 
{ 
    printf("Hello World from C \n"); 
    printf("1st string passed is %s \n ",argv[1]);
    printf("2nd string passed is %s \n ", argv[2]);
    char b[] = "success";
    return b; 
} 

This is the code in C from where I wish to return a string to the python code.

import subprocess 
import os 

def excuteC(): 

    s = subprocess.call("./Cvishad hello you;", shell = True)
    print("status is "+ str(s))


if __name__=="__main__": 
    excuteC()  

This is the code in python where I am calling the C code. It seems to work but I think it is returning a pointer/address but not the actual string "success" that I want. The output I get is something like this -

Hello World from C
1st string passed is hello 
2nd string passed is you 
status is 80

I'm trying out things for the first time in C, so kindly excuse the silly mistakes.

Answer 1

Your C program is returning a pointer to a string as the process return value, and it gets truncated to an unsigned byte (which you're seeing as eg 80).

You can transfer arbitrary data between processes by eg (and I'm sure I'm forgetting something)

• sockets
• files
• streams (stdout/stderr; subprocess.check_output() in Python)
• shared memory