fgets vs gets

Hi i am new to the topic about strings. Can i know what is the differences between fgets or gets? i cant seem to get the same output.

Code:

---

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


int main(void)
{
  char s1[80], s2[80];


  fgets(s1, 80, stdin);
  fgets(s2, 80, stdin);


  strcat(s1, s2);
  printf(s1);


  return 0;
}

---

and

Code:

---

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


int main(void)
{
  char s1[80], s2[80];


  gets(s1);
  gets(s2);


  strcat(s1, s2);
  printf(s1);


  return 0;
}

---

Thanks!

The string content should be the same... the difference is that fgets() includes a feature to limit input size preventing buffer overflows and gets does not...

Now you have one more problem... if you are going to strcat() your two strings, you potentially need a lot more than 80 characters... s1 should be declared for *at least* 160... the maximum length *after* joining the strings.

gets(s1) is unsafe when user input more than 80 chars

Quote:

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Originally Posted by wonderwall

Can i know what is the differences between fgets or gets?

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Other than what has already been mentioned about it being possible to use fgets safely whereas gets is inherently unsafe, one difference is fgets writes the newline character read into the buffer, whereas gets does not. This could account for the difference in output that you observed. Therefore, if this newline character is unwanted, you should search for it (e.g., with strchr) and replace it with a null character.

> printf(s1);
Also, NEVER pass an unknown string as the format string to printf.
All your malicious user has to do is type in a few % chars and the fun will begin.

Quote:

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Originally Posted by thlgood

gets(s1) is unsafe when user input more than 80 chars

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gets(s1) is unsafe when user input more than 79 chars