Reversing Letters in Words of a Sentence

I'm having trouble reversing the letters of words in a sentence, for instance:

Input: This is a test
Output: sihT si a tset

However, when I run the program and have the same input as above, my output is just the first word reversed. Here is my code:

Code:

 #include<stdio.h>
 #include<string.h>
 
 void rev_str(char *string, size_t length)
 {
  	int start, end;

  	for (start = 0, end = length-1; start < end; start++, end--)
  	{
    	char swap = string[start];
    	string[start] = string[end];
    	string[end] = swap;
  	}
 }

 char *rev_words(char *str)
 {
  	int length;
  	char *p = str, *next;

  	for (p = str; p != 0; p = strpbrk(p, " "))
  	{
    	if (*p == ' ')
   		{
      		p++;
   		}

    	next = strpbrk(p, " ");
		length = (next != 0) ? next - p : &str[strlen(str)] - p;
		rev_str(p, length);
 	}
  	return str;
 }

 int main(void)
 {
	char str[100];

	printf("Enter your sentence:");
	scanf("%s", str);
  	printf("%s\n", rev_words(str));

  	return 0;
 }

For starters, %s stops at whitespace... Fix how you read your input first.

Either I'm misunderstanding you, or it isn't doing much for me. With the adjustment I made it doesn't even print the first word reversed.

What adjustment have you made? You'll note that I didn't say I fixed your other problems. Rather, I said "fix how you read your input first". In other words, it won't matter if you try to fix your other problem, because if you aren't reading your input right in the first place, you won't be able to know if you're on the right track.

"Garbage in, garbage out", as the saying goes...


Quzah.

Originally Posted by quzah

For starters, %s stops at whitespace... Fix how you read your input first.

Yea try "%[^\n]\n" is stead of "%s"

Why not use fgets?

http://faq.cprogramming.com/cgi-bin/...&id=1043284385

Quzah.

Really it's your sscanf() that needs to be inside a loop.
This way the sentence is reversed a word at a time.
The way it is setup now it'll stop after reading the first word.

Originally Posted by quzah

Why not use fgets?

Cprogramming.com: FAQ

Quzah.

It's more work to make that change.

Originally Posted by esbo

It's more work to make that change.

Seriously?

Code:

fgets( buf, sizeof buf, stdin );

There, it's working.


Quzah.

Originally Posted by quzah

Seriously?

Code:

fgets( buf, sizeof buf, stdin );

There, it's working.


Quzah.

Yea I would say it is involved about 4-10 times as much work.

The difference is that I can break your program with input, and you can't break mine. How much "work" is it to figure out why I'm crashing your program?

On a side note, str is a reserved keyword, as is anything that starts with str.


Quzah.