From: Rasmus Villemoes > Sent: 23 July 2019 07:56 ... > > +/** > > + * stracpy - Copy a C-string into an array of char > > + * @to: Where to copy the string, must be an array of char and not a pointer > > + * @from: String to copy, may be a pointer or const char array > > + * > > + * Helper for strscpy. > > + * Copies a maximum of sizeof(@to) bytes of @from with %NUL termination. > > + * > > + * Returns: > > + * * The number of characters copied (not including the trailing %NUL) > > + * * -E2BIG if @to is a zero size array. > > Well, yes, but more importantly and generally: -E2BIG if the copy > including %NUL didn't fit. [The zero size array thing could be made into > a build bug for these stra* variants if one thinks that might actually > occur in real code.] Probably better is to return the size of the destination if the copy didn't fit (zero if the buffer is zero length). This allows code to do repeated: offset += str*cpy(buf + offset, src, sizeof buf - offset); and do a final check for overflow after all the copies. The same is true for a snprintf()like function David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
