c语言没有try catch的替代方案

#include <stdio.h>
#include <setjmp.h>

static jmp_buf buf;

void second(void) {
 printf("second\n"); 
 // 跳回setjmp的调用处 - 使得setjmp返回值为1  
 longjmp(buf, 1);    
}

void first(void) {
 second();
 //这行到不了，因为second里面longjmp已经跳转回去了
 printf("first\n");   
}

int main() {
 int rc;
 rc = setjmp(buf);
 if (rc==0) {  
  // 进入此行前，setjmp返回0
  first(); 
 }
 // longjmp跳转回，setjmp返回1，因此进入此行
 else if(rc==1){     
  printf("main\n");  
 }

 return 0;
}
/*
the ressult as:
 second
 main
*/

#define SIGINT   2 // interrupt
#define SIGILL   4 // illegal instruction - invalid function image
#define SIGFPE   8 // floating point exception
#define SIGSEGV   11 // segment violation
#define SIGTERM   15 // Software termination signal from kill
#define SIGBREAK  21 // Ctrl-Break sequence
#define SIGABRT   22 // abnormal termination triggered by abort call

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>

static void catch_function(int signal) {
 puts("Interactive attention signal caught.");
}

int main(void) {
 if (signal(SIGINT, catch_function) == SIG_ERR) {
  fputs("An error occurred while setting a signal handler.\n", stderr);
  return EXIT_FAILURE;
 }
 puts("Raising the interactive attention signal.");
 if (raise(SIGINT) != 0) {
  fputs("Error raising the signal.\n", stderr);
  return EXIT_FAILURE;
 }
 puts("Exiting.");
 return 0;
}