[prog] Another elementary 'C' question
David Sumbler
david at aeolia.co.uk
Tue Dec 14 08:56:12 EST 2004
Could somebody explain the significance of 'const' in C function
prototypes to me, please? I'm slightly confused.
fprintf, for instance, is shown as
int fprintf(FILE *stream, const char *format, ...)
Now, I imagine that the 'const' there means that fprintf won't change
the contents of the string *format.
But presumably it doesn't change the value pointed to by 'stream'
either, otherwise we'd get in a right old mess with subsequent actions
on the relevant file. But FILE isn't shown as 'const'.
So have I misunderstood something about 'const' in this sort of
context?
Or is it that the type 'FILE' itself is defined as a constant?
Or what?
David
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