On Dez 21 2018, Steven Rostedt <rost...@goodmis.org> wrote: > On Fri, 21 Dec 2018 12:46:47 -0800 > Joe Perches <j...@perches.com> wrote: > >> > + * @str: The string to test >> > + * @prefix: The string to see if @str starts with >> > + * >> > + * A common way to test a prefix of a string is to do: >> > + * strncmp(str, prefix, sizeof(prefix) - 1) >> > + * >> > + * But this can lead to bugs due to typos, or if prefix is a pointer >> > + * and not a constant. Instead use has_prefix(). >> > + * >> > + * Returns: 0 if @str does not start with @prefix >> > + strlen(@prefix) if @str does start with @prefix >> > + */ >> > +#define has_prefix(str, prefix) >> > \ >> > + ({ \ >> > + const char *____prefix____ = (const char *)(prefix); \ >> > + int ____len____ = strlen(____prefix____); \ >> > + strncmp(str, ____prefix____, ____len____) == 0 ? \ >> > + ____len____ : 0; \ >> > + }) >> >> I think all the underscores are unnecessary and confusing. >> > > Well, perhaps I can just remove the ending ones. I get paranoid with > macro variables, and tend to over do it so that there's no question.
Why not make it an inline function? Andreas. -- Andreas Schwab, sch...@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."