struct passwd *pw;
 
        errno = 0;
-       pw = getpwuid(getuid());
-       if (!pw) {
+       if (!(pw = getpwuid(getuid()))) {
                if (errno)
                        die("slock: getpwuid: %s\n", strerror(errno));
                else
                        die("slock: cannot retrieve password entry\n");
        }
-       rval =  pw->pw_passwd;
+       rval = pw->pw_passwd;
 
 #if HAVE_SHADOW_H
        if (rval[0] == 'x' && rval[1] == '\0') {
                struct spwd *sp;
-               sp = getspnam(getenv("USER"));
-               if (!sp)
+               if (!(sp = getspnam(getenv("USER"))))
                        die("slock: cannot retrieve shadow entry (make sure to suid or sgid slock)\n");
                rval = sp->sp_pwdp;
        }
                                        --len;
                                break;
                        default:
-                               if (num && !iscntrl((int) buf[0]) && (len + num < sizeof(passwd))) {
+                               if (num && !iscntrl((int)buf[0]) && (len + num < sizeof(passwd))) {
                                        memcpy(passwd + len, buf, num);
                                        len += num;
                                }
        XSetWindowAttributes wa;
        Cursor invisible;
 
-       if (dpy == NULL || screen < 0)
-               return NULL;
-
-       lock = malloc(sizeof(Lock));
-       if (lock == NULL)
+       if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(Lock))))
                return NULL;
 
        lock->screen = screen;
-
        lock->root = RootWindow(dpy, lock->screen);
 
        for (i = 0; i < NUMCOLS; i++) {
                        break;
                usleep(1000);
        }
-       if (running && (len > 0)) {
+       if (running && len) {
                for (len = 1000; len; len--) {
                        if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess)
                                break;
        if (!running) {
                unlockscreen(dpy, lock);
                lock = NULL;
-       }
-       else {
+       } else {
                XSelectInput(dpy, lock->root, SubstructureNotifyMask);
        }
 
        rr = XRRQueryExtension(dpy, &rrevbase, &rrerrbase);
        /* Get the number of screens in display "dpy" and blank them all. */
        nscreens = ScreenCount(dpy);
-       locks = malloc(sizeof(Lock *) * nscreens);
-       if (locks == NULL)
+       if (!(locks = malloc(sizeof(Lock*) * nscreens)))
                die("slock: malloc: %s\n", strerror(errno));
        int nlocks = 0;
        for (screen = 0; screen < nscreens; screen++) {
-               if ( (locks[screen] = lockscreen(dpy, screen)) != NULL)
+               if ((locks[screen] = lockscreen(dpy, screen)) != NULL)
                        nlocks++;
        }
        XSync(dpy, False);