uniq -u -i -d command implement in linux : I tried something but Resus mainly not know how to read the file line by line to compare lines between them, I get the error segmentation fault ( core dumped ).
This is my function for uniq -u command
    
    void uniq_u()
    {
    //  strcpy(file_name1,params[2]);
    FILE *file = fopen ( file_name1, "r" );
    if ( file != NULL )
    {
      
      fgets(prev, sizeof prev,file);
      while ( fgets ( line, sizeof line, file ) != NULL ) /* read a line */
      {
	 if(!strcmp(line, prev))
		
         	printf("%s", prev);
	 else 
		    strcpy(prev,line);
      }
      fclose ( file );
    }
    }
Thanks!