unwanted value in file reading

[er.rohan88]

if i read a file whenever i read it line by line while reading i try to check it with some string by the strcmp command .This is like thats
the string to be read from file is "rohan sharma".

while(fgets(bufrftext,1200,fp)
{ printf("the read string is :%s"bufftext");
i=strcmp(bufftext,"rohan sharma")

printf("the value of i :%d",i);
}

• the expected o/p is :
• the read string is : rohan sharma
• the value of i : 1// this o/p should always comes 0 .

please try to help me in this issue if want to remove the unwanted character that comes along the string which you read from file that makes string comparision impossible.

[Memloop]

When you read input with fgets the newline will be retained if the buffer is large enough.

[Adak]

So get rid of it.

#include <stdio.h>
#include <string.h>

int main() {
  char bufftext[] = "Let It Be";
  char buff2[80];
  int match;

  printf("\n\n >> %s    Enter your string: \n >> ", bufftext);

  fgets(buff2, 80, stdin);
  buff2[strlen(buff2)-1] = '\0';
  match = strcmp(bufftext, buff2);

  printf("\n %s \n %s", bufftext, buff2);

  if(!match)
    printf("\n\n strings are a match");
  else
    printf("\n\n strings are not a match");
  
  match = getchar();
  return 0;
}

[laserlight]

Adak's suggestion has an edge case problem: if it so happens that a particular line of input has 1199 characters, all of them will be stored, but the character at index 1198 will not be the newline that you want to remove (i.e., the newline will not have been stored in the first place).

To avoid this edge case problem, use strchr() to find the newline character, and if it is found, set it to be a null character.

[Adak]

Adak's suggestion has another problem.

If you have a char string declared like bufftext is, it won't have a newline char in it - just a terminating zero char.

So you have to watch out for that if you get in the habit of using this crazy way of removing a newline.

This line of code is from the forum tutorial, btw.

[laserlight]

If you have a char string declared like bufftext is, it won't have a newline char in it - just a terminating zero char.

True, but how is that a problem?

[Adak]

Just that it isn't a robust line of code. Either a while loop with an if in it, or strchr() is stronger code.

[er.rohan88]

I am facing the situation where i recieve the unwanted variable before and after the desired varaible is like that.

"[][] rohan sharma []";

i want to eliminate this variable.

[Adak]

I am facing the situation where i recieve the unwanted variable before and after the desired varaible is like that.

"[][] rohan sharma []";

i want to eliminate this variable.

OK, if you are "receiving" these unwanted char's, then you need to eliminate them. You need to keep one char after the last 'a', so C will know that this is a string, and not just a bunch of char's.

That's the end of string char, and usually looks like '\0' <== that.

This code will remove the last newline char which may or may not, be inside your string:

//You must include string.h

num i;
i = strlen(myString);
while(i > -1) {
  if(myString[i] == '\n')
    myString[i] = '\0';
  --i;
}

That will take care of the right hand side of your string, after it's read in from a file.

For the left hand side of your string, you can remove some junk char's if you want, but I'm very curious why they would be in your file, next to your name? Maybe there is junk getting into the file, that we should make sure never gets into your file?

In order to fix your code, you're going to have to post up your code that shows this problem. We're not seeing enough to run it and see what's going on, just yet.