漫话Redis源码之十九

看一下这个代码片段，再次展现了linux的严谨，既考虑了linux, 也考虑了 APPLE

#if __linux__
	if (!(tmp = strdup(program_invocation_name)))
		goto syerr;
 
	program_invocation_name = tmp;
 
	if (!(tmp = strdup(program_invocation_short_name)))
		goto syerr;
 
	program_invocation_short_name = tmp;
#elif __APPLE__
	if (!(tmp = strdup(getprogname())))
		goto syerr;
 
	setprogname(tmp);
#endif
 
    /* Now make a full deep copy of the environment and argv[] */
	if ((error = spt_copyenv(envc, envp)))
		goto error;
 
	if ((error = spt_copyargs(argc, argv)))
		goto error;
 
	SPT.nul  = nul;
	SPT.base = base;
	SPT.end  = end;
 
	return;
syerr:
	error = errno;
error:
	SPT.error = error;
} /* spt_init() */
 
 
#ifndef SPT_MAXTITLE
#define SPT_MAXTITLE 255
#endif
 
void setproctitle(const char *fmt, ...) {
	char buf[SPT_MAXTITLE + 1]; /* use buffer in case argv[0] is passed */
	va_list ap;
	char *nul;
	int len, error;
 
	if (!SPT.base)
		return;
 
	if (fmt) {
		va_start(ap, fmt);
		len = vsnprintf(buf, sizeof buf, fmt, ap);
		va_end(ap);
	} else {
		len = snprintf(buf, sizeof buf, "%s", SPT.arg0);
	}
 
	if (len <= 0)
		{ error = errno; goto error; }
 
	if (!SPT.reset) {
		memset(SPT.base, 0, SPT.end - SPT.base);
		SPT.reset = 1;
	} else {
		memset(SPT.base, 0, spt_min(sizeof buf, SPT.end - SPT.base));
	}
 
	len = spt_min(len, spt_min(sizeof buf, SPT.end - SPT.base) - 1);
	memcpy(SPT.base, buf, len);
	nul = &SPT.base[len];
 
	if (nul < SPT.nul) {
		*SPT.nul = '.';
	} else if (nul == SPT.nul && &nul[1] < SPT.end) {
		*SPT.nul = ' ';
		*++nul = '\0';
	}
 
	return;
error:
	SPT.error = error;
} /* setproctitle() */
 
 
#endif /* __linux || __APPLE__ */
#endif /* !HAVE_SETPROCTITLE */
 
#ifdef SETPROCTITLE_TEST_MAIN
int main(int argc, char *argv[]) {
	spt_init(argc, argv);
 
	printf("SPT.arg0: [%p] '%s'\n", SPT.arg0, SPT.arg0);
	printf("SPT.base: [%p] '%s'\n", SPT.base, SPT.base);
	printf("SPT.end: [%p] (%d bytes after base)'\n", SPT.end, (int) (SPT.end - SPT.base));
	return 0;
}
#endif