int x; != int x=0;

If I can guess what you're saying...

Global memory is guaranteed to be initialized to 0 but stack variables are not.

If it's inconsistent output from print, this may be a problem on the receiving side. In some terminals, if you output a character at a time, the terminal doesn't refresh until it hits a newline or a buffer boundary (like every 1KB of input). So sending endless '.' to show progress, for example, doesn't always give the user consistent feedback.