Problem with fgets reading last line over and over

[Trond Valen]

Hi!

Anyone who knows what the reason might be? fgets is supposed to return
null when reading EOF. I have a test for this, so my while loop should
exit, but it doesn't ...

Trond

 

[Karl Heinz Buchegger]

Hi!

Anyone who knows what the reason might be? fgets is supposed to return
null when reading EOF. I have a test for this, so my while loop should
exit, but it doesn't ...

Rule #1: Post Code

 

[Niklas Norrthon]

Hi!

Anyone who knows what the reason might be? fgets is supposed to return
null when reading EOF. I have a test for this, so my while loop should
exit, but it doesn't ...

You forgot to post any code illustrating the observed behavior, so it
is very difficult to know what the reason might be.

The following should work:

#include <stdio.h>

int main()
{
char buf[42];
char* ptr;

while ((ptr = fgets(buf, sizeof buf, stdin)) != NULL) {
/* do something with buf here */
}
return 0;
}

/Niklas Norrthon

 

[mlimber]

Hi!

Anyone who knows what the reason might be? fgets is supposed to return
null when reading EOF. I have a test for this, so my while loop should
exit, but it doesn't ...

Trond

Rule #2: Prefer iostreams to C-style file streams:

http://www.parashift.com/c++-faq-lite/input-output.html#faq-15.1

Cheers! --M

 

[deane_gavin]

Hi!

Anyone who knows what the reason might be? fgets is supposed to return
null when reading EOF. I have a test for this, so my while loop should
exit, but it doesn't ...

Trond

Rule #3: Make sure you test eof correctly with your C++ streams

http://www.parashift.com/c++-faq-lite/input-output.html#faq-15.5

Gavin Deane

 

[Niklas Norrthon]

Rule #3: Make sure you test eof correctly with your C++ streams

Rule #4: If you for some reason use C style I/O, make sure you test
eof correctly with your FILE objects.

/Niklas Norrthon