nologin(8) overhaul

[Benjamin Baier]

A /usr/bin/false vs. /sbin/nologin argument led me to nologin(8) so
here are some suggestions.

- de-lint
- return instead of exit()
- no need to tell an *possible evil* ssh user that pledge(2) failed
- some more churn/clean up

Greetings Ben

Index: nologin.c
===================================================================
RCS file: /cvs/src/sbin/nologin/nologin.c,v
retrieving revision 1.6
diff -u -p -r1.6 nologin.c
--- nologin.c   13 Oct 2015 07:10:38 -0000      1.6
+++ nologin.c   6 Mar 2016 08:46:24 -0000
@@ -26,19 +26,14 @@
  */
 
 #include <sys/types.h>
-#include <err.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
-/* Distinctly different from _PATH_NOLOGIN. */
-#define _PATH_NOLOGIN_TXT      "/etc/nologin.txt"
-
 #define DEFAULT_MESG   "This account is currently not available.\n"
 
-/*ARGSUSED*/
 int
 main(int argc, char *argv[])
 {
@@ -47,17 +42,16 @@ main(int argc, char *argv[])
        char nbuf[BUFSIZ];
 
        if (pledge("stdio rpath", NULL) == -1)
-               err(1, "pledge");
+               return (1);
 
-       nfd = open(_PATH_NOLOGIN_TXT, O_RDONLY);
-       if (nfd < 0) {
+       nfd = open("/etc/nologin.txt", O_RDONLY);
+       if (nfd < 0)
                write(STDOUT_FILENO, DEFAULT_MESG, strlen(DEFAULT_MESG));
-               exit (1);
+       else {
+               while ((nrd = read(nfd, nbuf, sizeof(nbuf))) != -1 && nrd != 0)
+                       write(STDOUT_FILENO, nbuf, nrd);
+               close (nfd);
        }
 
-       while ((nrd = read(nfd, nbuf, sizeof(nbuf))) != -1 && nrd != 0)
-               write(STDOUT_FILENO, nbuf, nrd);
-       close (nfd);
-
-       exit (1);
+       return (1);
 }