Exercise 1.18 - Remove trailing blanks and tabs¶

/**
 *
 * Exercise 1.18 - Write a Program to remove the trailing blanks and tabs
 * from each input line and to delete entirely blank lines
 *
 **/

#include <stdio.h>

#define MAXLINE 1000

int _getline(char line[], int lim);

int remove_trail(char rline[]);

int main(void) {
    int len;
    char line[MAXLINE];

    while ((len = _getline(line, MAXLINE)) > 0)
        if (remove_trail(line) > 0)
            printf("%s", line);

    return 0;
}

int _getline(char line[], int lim) {
    int i, c;

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

    return i;
}

/* To remove Trailing Blanks,tabs. Go to End and proceed backwards removing */
int remove_trail(char rline[]) {
    int i;

    for (i = 0; rline[i] != '\n'; ++i);
    --i; /* To consider raw line without \n */

    for (i > 0; ((rline[i] == ' ') || (rline[i] == '\t')); --i); /* Removing the Trailing Blanks and Tab Spaces */

    if (i >= 0) /* Non Empty Line */
    {
        ++i;
        rline[i] = '\n';
        ++i;
        rline[i] = '\0';
    }
    return i;
}