analyze text

#include <stdio.h>
#include <malloc.h>
 
int main() {
	const int l_block = 1024;
 
	FILE* input_text_file;
	long n = 0, i = 0, j = 0;
	int meet_comma = 0;
	long file_lengh;
	char* buffer;
	int num_block;
 
 
	input_text_file = fopen( "../../additional_files/en.txt", "r" );	
	if ( !input_text_file ) {
		puts( "Can't open file!" );
		return 1;
	}
 
	fseek( input_text_file, 0, SEEK_END );
	file_lengh = ftell( input_text_file );
	buffer = (char*) malloc(  (file_lengh + 1) * sizeof(char)  );
 
	num_block = file_lengh / l_block;
	fseek( input_text_file, 0, SEEK_SET );
	fread( buffer, l_block, num_block + 1, input_text_file );
	buffer[file_lengh] = '\0';
 
/* -----------------------------  PROCESSING  ------------------------------ */
 
	while( buffer[i]) {
		switch ( buffer[i] ) {
			case ',':
				meet_comma = 1;
				break;
			case '.':
			case '!':
			case '?':
				if ( !meet_comma )   /* Если запятой небыло. */
					for ( j = n; j <= i; j++ )
						putchar( buffer[j] );
				meet_comma = 0;
				n = i + 1;
				break;
			default: break;
		}
		i++;
	}
 
/* ------------------------------------------------------------------------- */
 
	fclose ( input_text_file );
	free(buffer);
	puts("");
 
	return 0;
}