Broken link to stdin?

I am writing a php program to get and parse input from stdin.

To open stdin, I tried writing:
fopen("/dev/stdin", "r");
and:
fopen("/dev/fp/0", "r");

Both failed.

I am working on Linux so I decided to do some detective work.

I did a file on /dev/stdin and I got:
/dev/stdin: symbolic link to fd/0
Then I did a file on fd/0 and I got:
/dev/fd/0: broken symbolic link to [0301]:524912


What does this mean??

Am I doing something wrong or is the problem in the configuration?

Thanks!