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#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);
}
}
}
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