How do you truncate a file?

[Doug Gwyn]

In article <12653 at sybase.sybase.com> djd at sirdan.sybase.com (dan debrunner) writes:
>Actually a correct way would have been even better. Remember putchar()
>is a macro on many platforms which evaluates its argument twice.

It had better not be -- that is not only not conformant to the C standard,
it would break LOTS of code, such as the putchar(getchar()) loop.