#include <stdio.h>

/* The C Programming Language: 2nd Edition
 *
 * Exercise 1-18: Write a program to remove trailing blanks and tabs from each
 * line of input, and to delete entirely blank lines.
 *
 * Answer: Simple -- start from the end of the line and look for a non-blank
 * character. Once found, place your \n and \0 just afterwards. By checking
 * that 'i' > 1, it ensures that blank lines never get spit out, since a line
 * with content will always be 2 or more characters long due to the \n.
 */
#define MAXLINELENGTH 9001

int get_line(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 + 1] = '\0';
	return i;
}

int main(void) {
	char buffer[MAXLINELENGTH];
	int c, i, len;
	/* Make sure every line is gone over */
	while (len = get_line(buffer, MAXLINELENGTH)) {
		/* An empty for statement, simply to change the i variable.
		 * Subtracting 2 from 'len' is to account for 0-based indexing and the \0
		 * string terminator.
		 */
		for (i = len - 2; (i > 0) && (buffer[i] == ' ') || (buffer[i] == '\t'); --i);
		/* We've reached the end of the line's actual content. Terminate the line. */
		if (i >= 1) {
			buffer[i + 1] = '\n';
			buffer[i + 2] = '\0';
			printf("%s", buffer);
		}
	}
}