C中使用_start（）是什么？(What is the use of _start() in C?)

 从我的同事那里得知，可以编写和执行一个C程序，而无需编写一个main()函数。 它可以做到下面 
 
 withoutMain.c 
 
// Compile it with gcc -nostartfiles

void _start() {
  int ret = my_main();
  exit(ret); 
}

int my_main() {
  puts("This is a program without main!\n");
  return 0; 
}
 
 编译为： gcc -o withoutMain withoutMain.c –nostartfiles 
 
 运行它： ./ withoutMain 
 
 我的问题是什么时候需要做这样的事情？ 一些现实世界的场景？ 

I learned from my colleague that one can write and execute a C program without writing a main() function. It can be done like this:
 
my_main.c
 
/* Compile this with gcc -nostartfiles */

#include <stdlib.h>

void _start() {
  int ret = my_main();
  exit(ret); 
}

int my_main() {
  puts("This is a program without a main() function!");
  return 0; 
}
 
Compile it with this command:
 
gcc -o my_main my_main.c –nostartfiles
 
Run it with this command:
 
./my_main
 
When would one need to do this kind of thing? Is there any real world scenario where this would be useful?

原文：https://stackoverflow.com/questions/29694564