1-19.c

//K&R2 Exercise 1-19 "Reverse string"

#include <stdio.h>

#define MAX_LENGTH 1024

int getline(char[], int);
void reverse(char[], int);

int main()
{
	int i;
	char line[MAX_LENGTH];

	while((i = getline(line, MAX_LENGTH)) > 0){
		reverse(line, i);
		printf("%s", line);
	}
	return 0;
}

int getline(char s[], int lim)
{
	int c, i;

	for(i = 0; i < lim-1 && (c = getchar()) != EOF && c !='\n'; ++i)
		s[i] = c;
	if(c == '\n') {
		s[i] = c;
		++i;
	}
	s[i] = '\0';
	return i;
}

void reverse(char s[], int size)
{
	int i;
	char r;
	for(i = 0; i < size/2; i++){
		r = s[i];
		s[i] = s[size - i - 2];
		s[size - i - 2] = r;
	}
}