solutions/The C Programming Language/1.18.c

#include <stdio.h>

#define MAXLINE 10

int _getline(char line[], int maxline);
void trim(char to[], char from[], int from_head);

// remove all extra spaces and tabs from tail of input

main()
{
	char line[MAXLINE];
	char trimmed[MAXLINE];

	int head = _getline(line, MAXLINE);
	trim(trimmed, line, head);

	printf("[%s]\n", trimmed);

	return 0;
}

int _getline(char s[], int lim)
{
	int c, i, j;
	for (i = 0; (c = getchar()) != '\n'; ++i)
	{
		if (i < lim - 1)
			s[i] = c;
	}

	j = i;
	if (j > lim - 1)
		j = lim - 1;
	s[j] = '\0';
	return j;
}

void trim(char to[], char from[], int from_head)
{
	int i;
	int start_copying = 0;

	for (i = from_head - 1; i >= 0; --i)
	{
		if (start_copying == 0 && from[i] != '\t' && from[i] != ' ')
		{
			to[i+1] = '\0';
			start_copying = 1;
		}
	
		if (start_copying == 1)
			to[i] = from[i];
	}
}