How to implement `.nf` formatting feature - c

Question

I have written a program that reads a text file inputted by the user, and inside the file contains formatting features such as .br , .sp and .nf.
.nf symbolises no fill, also meaning that when you see any formatting feature after .nf they should all be ignored and it should just output the text in the format it originally appears in the text file.
For example:
.nf Hello my name is .br Jay.
Output:
Hello my name is Jay
If .nf was not there the output would be:
Hello my name is
Jay.
Here's my code:
int main(void) {
FILE *fp = NULL;
char file_name[257] = {'\0'};
char line[61] = {'\0'};
char word[61] = {'\0'};
int out = 0;
int blanks;
int space;
int useFormats = 1;
printf ( "Enter file name:\n");
scanf ( " %256[^\n]", file_name);
if ( ( fp = fopen ( file_name, "r")) == NULL) {
printf ( "could not open file\n");
return 1;
}
while (useFormats == 1){
while ( ( fscanf ( fp, "%60s", word)) == 1) { //breaks the sentence after .br
if ( strcmp ( word, ".br") == 0) {
printf ( "%s\n", line);
line[0] = '\0';
out = 1;
}
if ( strcmp ( word, ".nf") == 0) {// stop filling lines (no fill)
useFormats == 0;
line[0] = '\0';
out = 1;
}
if ( strncmp ( word, ".sp", 3) == 0) { // creates n amount of spaces after .sp
if ( ( sscanf ( &word[3], "%d", &blanks)) == 1) {
printf ( "%s\n", line);
while ( blanks) {
blanks--;
printf ( "\n");
}
line[0] = '\0';
out = 1;
}
else {
printf ( "%s\n", line);
line[0] = '\0';
out = 1;
}
}
else if ( strlen ( line) + strlen ( word) + 1 < 60) {
strcat ( line, " ");
strcat ( line, word);
out = 0;
}
else {
printf ( "%s\n", line);
strcpy ( line, word);
out = 1;
}
}
if ( !out) {
printf ( "%s\n", line);
}
fclose ( fp);
return 0;
}
}
I tried creating a variable called useFormats which is true whilst running and I make it false when it reaches to the .nf feature but nothing happens. I'm not sure if I should remove the if statement and create another while loop to say while (useFormats == 0) to implement the .nf feature.

Answer 1

This should capture the ".nf" token and set useFormats to zero. Adding if ( useFormats == 1) { to the other format conditions should disable them.
#include <stdio.h>
#include <string.h>
#define WIDTH 80
int main(void) {
FILE *fp = NULL;
char file_name[257] = {'\0'};
char line[61] = {'\0'};
char word[61] = {'\0'};
int out = 0;
int blanks = 0;
int center = 0;
int useFormats = 1;
int margin = 0;
printf ( "Enter file name:\n");
scanf ( " %256[^\n]", file_name);
if ( ( fp = fopen ( file_name, "r")) == NULL) {
printf ( "could not open file\n");
return 1;
}
while ( ( fscanf ( fp, "%60s", word)) == 1) {// read file to end one word at a time
if ( strcmp ( word, ".nf") == 0) {// no formatting)
useFormats = 0;
center = 0;
continue;
}
if ( strncmp ( word, ".ce", 3) == 0) {
if ( useFormats == 1) {
if ( ( sscanf ( &word[3], "%d", &center)) != 1) {
center = 0;
}
}
continue;
}
if ( strncmp ( word, ".sp", 3) == 0) {
if ( useFormats == 1) {
if ( ( sscanf ( &word[3], "%d", &blanks)) == 1) {
margin = 0;
if ( center) {
margin = WIDTH - ( ( WIDTH - strlen ( line)) / 2);
center--;
}
printf ( "%*s\n", margin, line);
while ( blanks) {
blanks--;
printf ( "\n");
}
line[0] = '\0';
out = 1;
}
else {
margin = 0;
if ( center) {
margin = WIDTH - ( ( WIDTH - strlen ( line)) / 2);
center--;
}
printf ( "%*s\n", margin, line);
line[0] = '\0';
out = 1;
}
}
continue;
}
if ( strcmp ( word, ".br") == 0) {
if ( useFormats == 1) {
margin = 0;
if ( center) {
margin = WIDTH - ( ( WIDTH - strlen ( line)) / 2);
center--;
}
printf ( "%*s\n", margin, line);
line[0] = '\0';
out = 1;
}
continue;
}
if ( strlen ( line) + strlen ( word) + 1 <= 60) {
strcat ( line, " ");
strcat ( line, word);
out = 0;
}
else {
margin = 0;
if ( center) {
margin = WIDTH - ( ( WIDTH - strlen ( line)) / 2);
center--;
}
printf ( "%*s\n", margin, line);
strcpy ( line, word);
out = 1;
}
}
if ( !out) {
margin = 0;
if ( center) {
margin = ( WIDTH - strlen ( line)) / 2;
center--;
}
printf ( "%*s\n", margin, line);
}
fclose ( fp);
return 0;
}

Answer 2

As long as this: while ( ( fscanf ( fp, "%60s", word)) == 1) evaluates as true it will never break from the while current inner while loop. You can break out of the inner while loop with break; after your condition is met. It will then check the condition and break out of the main while loop. You also don't assign a value with ==. That operand is for evaluation.
if ( strcmp ( word, ".nf") == 0) {// stop filling lines (no fill)
useFormats = 0;
line[0] = '\0';
out = 1;
break;
}