Read file in C line by line

Below is the program to read txt file in c line by line. To understand program, you must have knowledge of Files I/O and Strings.

void perror(const char *str) :

if file "filename.txt" is empty, then it will print descriptive error message to stderr using perror() function.

char *fgets(char *str, int n, FILE *stream) :

fgets() functions reads the file line. It reads the line until the maximum length of an array or new line character encounters.

int fputs(const char *str, FILE *stream) :

The fputs() function writes line of characters into a file. It outputs string to a stream.

int fclose(FILE *fp) :

fclose() function closes the file that is being printed by the file pointer.

#include <stdio.h>
int main ( void )
{
   static const char filename[] = "filename.txt";
   FILE *file = fopen ( filename, "r" );
   if ( file != NULL )
   {
      char line [ 128 ]; /* line size */
      while ( fgets ( line, sizeof line, file ) != NULL ) /* read the file line */
      {
         fputs ( line, stdout ); /* write the line */
      }
      fclose ( file );
   }
   else
   {
      perror ( filename );
   }
   return 0;
}