What does collect2 error ld returned 1 exit status mean

Question

I see the error collect2: error: ld returned 1 exit status very often. For example, when I was executing the following snippet of code I got the following:-

void main() { 
    char i; 

      printf("ENTER i"); 
      scanf("%c",&i); 

      clrscr(); 
  
      switch(i) { 
          default: 
              printf("\nHi..\n"); 
              break; 
          case 1: 
            printf("\n\na"); 
            break; 
          case 2: 
            printf("\nb\n"); 
            break; 
          case 3: 
              printf("\nc"); 
              break; 
      } 
}

 

Following which, I got this:

main.c:(.text+0x33): undefined reference to `clrscr' 
collect2: error: ld returned 1 exit status

Could anyone help me understand what it means?

Answer 1

 The ld returned 1 exit status error is the consequence of your previous errors as in your example there is an earlier error - undefined reference to 'clrscr' - and this is the real one. The exit status error just signals that the linking step in the build process encountered some errors. Normally exit status 0 means success, and exit status > 0 means errors. Various tools may be running while creating a program as separate steps to create the final executable. In your case one of those tools is ld, which first reports the error it found (clrscr reference missing), and then it returns the exit status. Since the exit status is > 0, it means an error and is reported.

In many cases tools return as the exit status the number of errors they encountered. So if the old tool finds two errors, its exit status would be 2.