C Language Zemi

__LINE__ --line number

"__LINE__" is expanded by preprocessor to the line number of the line where "__LINE__" is written in the file where the source code is written.

__LINE__

Sample to get line number

#include <stdio.h>

int main (void) {
  printf("%d\n", __LINE__);
}

Output result.

Four

Sample to display an error message and exit the program

A sample that combines the exit function, __FILE__, and __LINE__ to display an error message and exit the program is exit function description.