While not working :(

I've been stuck just trying to figure out what's wrong with my while loop and I can't get it...

I'm opening up a .dat file and I want the while loop to keep looping until it reads a string that says, "End of file" Here's what I have.

Code:

fgets (item, 25, inputfile);
printf ("\n%s", item); 

while (item != "End of data") 
{
       printf ("\n%s", item); 
      /***** blah, blah, blah....                  ******
       ***** update to read the next item ******/
       fgets (item, 25, inputfile);
}

Anyone know where I've gone wrong???

~fatty acid

Code:

while (item != "End of data")

If you want to compare strings, use the function strcmp.

~/

i was told to try that too, but i'm not sure what i'm comparing and i get errors when i just type:

Code:

while (strcmp(item)!="End of data")

I also tried:

Code:

while (fgets (item, 25, inputfile)!="End of data")

but that doesn't work as well. I'm just basically trying to express the algorithm "While the item (string) being read does not read 'End of data' keep doing so and so." Would placing each item read into an array of strings help?

~fatty acid

ps - i strictly only know C basics. I'm not too advanced.

would this work?

Code:

while (!strcmp(fgets (item, 25, inputfile)), "End of file")
{
       printf ("\n%s", item); 
}

Originally Posted by fatty acid

i was told to try that too, but i'm not sure what i'm comparing and i get errors when i just type:

Code:

while (strcmp(item)!="End of data")

Your strcmp isn't correct, it has to be strcmp(string1, string2). In your case it would be strcmp(item, "End of data")

Originally Posted by mapunk

Your strcmp isn't correct, it has to be strcmp(string1, string2). In your case it would be strcmp(item, "End of data")

would this work?

Code:

while (!strcmp(fgets (item, 25, inputfile)), "End of file")
{
       printf ("\n%s", item); 
}

You've got a misplaced parenthesis...

Code:

while(!strcmp(fgets(item, 25, inputfile), "End of file"))
{
       printf ("\n%s", item); 
}

The only problem with this is using the return value of fgets() that way. fgets() will return NULL on error or EOF without any read, which would then get passed to strcmp() - and bad things happen from there.

You can also read up on what strcmp does for return codes, etc.

then could you just do this:

Code:

while(fgets(item, 25, inputfile) != EOF )
{
       if (!strcmp(item, "End of file"))
       {
              printf ("\n%s", item); 
       }
}

this could be one of the solution for the problem

Code:

#include<stdio.h>

int main()
{
 	char *p;
 	char temp[80];
 	FILE *fp;
 	
 	if((fp=fopen("test.txt","r"))==NULL)
 	{
	   printf("Error: File cannot be opened");
	   getchar();
	   exit(1);
    }
    else
    {
	 while(fgets(temp,80,fp)!=NULL)
	 {
	      if((p=strstr(temp,"End of File"))!=NULL)
	      {
	                   printf("You have reached \"%s\"",p);
		     getchar();
   		      break;
	     }
	}
     }
} 	

/* test file
hello sir 
hoe are you? End of File 

my output
You have reached "End of File "
*/

ssharish2005

Originally Posted by mapunk

then could you just do this:

Code:

while(fgets(item, 25, inputfile) != EOF )
{
       if (!strcmp(item, "End of file"))
       {
              printf ("\n%s", item); 
       }
}

with a few minor adjustments, that worked! thank you SOOOOO much.

~fatty acid