Style: evaluate false expressions to boolean, just as true expressions.

userhosts.c

@@ -48,7 +48,7 @@ static inline void *dlsym_or_abort(const char *name) {
   void *symbol;
   dlerror(); /* Clear any previous error */
   symbol = dlsym(RTLD_NEXT, name);
-  if (NULL == symbol && (error = dlerror())) {
+  if (!symbol && (error = dlerror())) {
     fprintf(stderr, "Error loading '%s': %s\n", name, error);
     abort();
   }
@@ -59,13 +59,13 @@ static void __attribute__ ((constructor)) init(void) {
   original_open = dlsym_or_abort("open");
   original_fopen = dlsym_or_abort("fopen");
   replacement_hosts = getenv("HOSTS");
-  if (replacement_hosts == NULL)
+  if (!replacement_hosts)
     /* XXX: warn ? fallback on $HOME/???/hosts ? */
     replacement_hosts = ORIGINAL_HOSTS_PATH;
 }
 
 int open(const char *__file, int __oflag, ...) {
-  if (strcmp(__file, ORIGINAL_HOSTS_PATH) == 0)
+  if (!strcmp(__file, ORIGINAL_HOSTS_PATH))
     __file = replacement_hosts;
   if (__oflag & (O_CREAT | PURE_O_TMPFILE)) {
     va_list ap;
@@ -80,7 +80,7 @@ int open(const char *__file, int __oflag, ...) {
 }
 
 FILE *fopen(const char *path, const char *mode) {
-  if (strcmp(path, ORIGINAL_HOSTS_PATH) == 0)
+  if (!strcmp(path, ORIGINAL_HOSTS_PATH))
     path = replacement_hosts;
   return (*original_fopen)(path, mode);
 }