Extracting a string from a buffer?

tetradtech · 10-09-2002, 10:32 PM

Again, I'm really new at this. I've tried searching on strings, strstr, etc. Stuff I found didn't seem to apply.

Code:

char *domainResponse=malloc(1000);

while(fgets(domainResponse, 1000, fp) != NULL)
  {
    /* String function here to search for 'no match for domain' */
    /*fputs(domainResponse, stdout);*/
 	
  }
  printf("%s\n", domainResponse);

I get nothing printed out.

Now, if I remove the comments from line 3 like this:

Code:

char *domainResponse=malloc(1000);

while(fgets(domainResponse, 1000, fp) != NULL)
  {
    /* String function here to search for 'no match for domain' */
    fputs(domainResponse, stdout);
	        	
  }
  /*printf("%s\n", domainResponse);*/

I get the results of the bw-whois lookup printed to the screen (actually, a html page)

I tried a strstr(domainResponse, "No match for domain") - but it always returned NULL, which led me to check what was in domainResponse. Seems if I do the fputs, domainResponse contains text; but if I just try to printf it, domainResponse seems empty. With the fputs operation, domainResponse has a long text paragraph.

Please help.

Thanks,
Tim

starX · 10-09-2002, 10:47 PM

did you try it this way?:

Code:

while(fgets(domainResponse, 1000, fp))
{
.
.
.
}

starX
www.axisoftime.com

tetradtech · 10-09-2002, 11:00 PM

After I read your reply, I tried as you suggested. Using the code with the fputs() commented out and the printf() attempting to print domainResponse.

Same result. I'll leave as is and you can see - if you'd like.

http://www.tetradtech.com/domain_check.htm

What you should see on the page after you click on "submit" would be a paragraph responding with whether the domain was available or not.

Unfortunately, that doesn't show up.

Thanks,
Tim

tetradtech · 10-10-2002, 07:43 AM

Again, I'm new at this.

But when you place the results from stdout or stdin into a variable, that variable should contain whatever was read in, yes?

Whether domainResponse is in the while() statement or wherever, it should contain the results of the domain search.

But I think I'm on to something here, when I moved the fgets() out of the while() and the printf() out of the while(), I only get one line printed out. That's because fgets() reads until it encounters a '\0', correct?

So maybe the bw-whois is producing a newline at the end, and that's the last thing in the domainResponse variable.

-Tim

tetradtech · 10-10-2002, 08:40 AM

That was it...helps to print results to see what's actually happening and to include <br> in your html to see if text is split or one long paragraph. Apparently, the bw-whois prints the output as 4 or 5 separate paragraphs separated by newlines, so the last input into the buffer was a newline.

This bit of code fixed the problem and it's FINALLY working. Thanks again for all of your help to this error-prone newbie.

Code:

while(fgets(domainResponse, 1000, fp))
  {
    strcat(temp, domainResponse);
		
  }
  	
  printf("<br>\n");
  if(strstr(temp, "No match for domain")!=NULL)
  {
    printf("<b>The domain: %s is available!</b>\n", cgivars[1]);
  }
  else
  {
    printf("<b>The domain: %s is unavailable.</b>\n", cgivars[1]);
  }

Thanks again!

tetradtech · 10-10-2002, 10:58 AM

Code:

char temp = malloc(1000);

**Salem** · 10-10-2002, 11:32 AM

So why not do strstr on each line as you read it (then set a flag if you find it), rather than risk a buffer overflow with all those strcat's to temp

Code:

int found = 0;
while( !found && fgets(domainResponse, 1000, fp) ) {
  found = strstr( domainResponse, "No match for domain") != NULL ; 
}
if ( found ) {
  printf("<b>The domain: %s is available!</b>\n", cgivars[1]);
} else {
  printf("<b>The domain: %s is unavailable.</b>\n", cgivars[1]);
}

10-09-2002, 10:32 PM	#1
tetradtech Registered User Join Date: Oct 2002 Posts: 13	Extracting a string from a buffer? Again, I'm really new at this. I've tried searching on strings, strstr, etc. Stuff I found didn't seem to apply. Code: char domainResponse=malloc(1000); while(fgets(domainResponse, 1000, fp) != NULL) { / String function here to search for 'no match for domain' / /fputs(domainResponse, stdout);/ } printf("%s\n", domainResponse); I get nothing printed out. Now, if I remove the comments from line 3 like this: Code: char domainResponse=malloc(1000); while(fgets(domainResponse, 1000, fp) != NULL) { /* String function here to search for 'no match for domain' / fputs(domainResponse, stdout); } /printf("%s\n", domainResponse);*/ I get the results of the bw-whois lookup printed to the screen (actually, a html page) I tried a strstr(domainResponse, "No match for domain") - but it always returned NULL, which led me to check what was in domainResponse. Seems if I do the fputs, domainResponse contains text; but if I just try to printf it, domainResponse seems empty. With the fputs operation, domainResponse has a long text paragraph. Please help. Thanks, Tim
tetradtech is offline

10-09-2002, 10:47 PM	#2
starX Registered User Join Date: Aug 2001 Posts: 202	did you try it this way?: Code: while(fgets(domainResponse, 1000, fp)) { . . . } starX www.axisoftime.com
starX is offline

10-09-2002, 11:00 PM	#3
tetradtech Registered User Join Date: Oct 2002 Posts: 13	After reading your post, yes... After I read your reply, I tried as you suggested. Using the code with the fputs() commented out and the printf() attempting to print domainResponse. Same result. I'll leave as is and you can see - if you'd like. http://www.tetradtech.com/domain_check.htm What you should see on the page after you click on "submit" would be a paragraph responding with whether the domain was available or not. Unfortunately, that doesn't show up. Thanks, Tim
tetradtech is offline

10-10-2002, 07:43 AM	#4
tetradtech Registered User Join Date: Oct 2002 Posts: 13	*Not a duh* IMHO** Again, I'm new at this. But when you place the results from stdout or stdin into a variable, that variable should contain whatever was read in, yes? Whether domainResponse is in the while() statement or wherever, it should contain the results of the domain search. But I think I'm on to something here, when I moved the fgets() out of the while() and the printf() out of the while(), I only get one line printed out. That's because fgets() reads until it encounters a '\0', correct? So maybe the bw-whois is producing a newline at the end, and that's the last thing in the domainResponse variable. -Tim
tetradtech is offline

10-10-2002, 08:40 AM	#5
tetradtech Registered User Join Date: Oct 2002 Posts: 13	Found the problem... That was it...helps to print results to see what's actually happening and to include <br> in your html to see if text is split or one long paragraph. Apparently, the bw-whois prints the output as 4 or 5 separate paragraphs separated by newlines, so the last input into the buffer was a newline. This bit of code fixed the problem and it's FINALLY working. Thanks again for all of your help to this error-prone newbie. Code: while(fgets(domainResponse, 1000, fp)) { strcat(temp, domainResponse); } printf("<br>\n"); if(strstr(temp, "No match for domain")!=NULL) { printf("<b>The domain: %s is available!</b>\n", cgivars[1]); } else { printf("<b>The domain: %s is unavailable.</b>\n", cgivars[1]); } Thanks again!
tetradtech is offline

10-10-2002, 10:58 AM	#6
tetradtech Registered User Join Date: Oct 2002 Posts: 13	size of temp Code: char temp = malloc(1000);
tetradtech is offline

10-10-2002, 11:32 AM	#7
Salem and the hat of Jobseeking Join Date: Aug 2001 Location: The edge of the known universe Posts: 21,710	So why not do strstr on each line as you read it (then set a flag if you find it), rather than risk a buffer overflow with all those strcat's to temp Code: int found = 0; while( !found && fgets(domainResponse, 1000, fp) ) { found = strstr( domainResponse, "No match for domain") != NULL ; } if ( found ) { printf("<b>The domain: %s is available!</b>\n", cgivars[1]); } else { printf("<b>The domain: %s is unavailable.</b>\n", cgivars[1]); } __________________ If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
Salem is offline

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