in reply to
Re: substitute 4 spaces instead of a tab
in thread substitute 4 spaces instead of a tab
With regards to not truncating anything accidentally, davido mentioned this excellent suggestion: move the original file out of the way first (e.g. if it's called shock_api.h, call it shock_api.h.bak or similar; there's a built-in called rename to do this), then read in from shock_api.h.bak and write out to shock_api.h.
This solves the simultaneous read/write truncation issue, and creates a backup for you in case things go awry.