[src/trunk]: src/usr.bin/flock - better usage messages

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/42bd75a83339
branches:  trunk
changeset: 782425:42bd75a83339
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Nov 02 17:03:16 2012 +0000

description:
- better usage messages
- verbose can be local
- add static

diffstat:

 usr.bin/flock/flock.c |  64 +++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 49 insertions(+), 15 deletions(-)

diffs (153 lines):

diff -r 8b80084bb660 -r 42bd75a83339 usr.bin/flock/flock.c
--- a/usr.bin/flock/flock.c     Fri Nov 02 16:55:02 2012 +0000
+++ b/usr.bin/flock/flock.c     Fri Nov 02 17:03:16 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: flock.c,v 1.5 2012/11/02 12:47:23 christos Exp $       */
+/*     $NetBSD: flock.c,v 1.6 2012/11/02 17:03:16 christos Exp $       */
 
 /*-
  * Copyright (c) 2012 The NetBSD Foundation, Inc.
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: flock.c,v 1.5 2012/11/02 12:47:23 christos Exp $");
+__RCSID("$NetBSD: flock.c,v 1.6 2012/11/02 17:03:16 christos Exp $");
 
 #include <stdio.h>
 #include <string.h>
@@ -45,7 +45,7 @@
 #include <paths.h>
 #include <time.h>
 
-struct option flock_longopts[] = {
+static struct option flock_longopts[] = {
        { "debug",              no_argument,            0, 'd' },
        { "help",               no_argument,            0, 'h' },
        { "nonblock",           no_argument,            0, 'n' },
@@ -61,18 +61,27 @@
        { NULL,                 0,                      0, 0   },
 };
 
-static int verbose = 0;
 static sig_atomic_t timeout_expired;
 
-static __dead void usage(void) 
+static __dead void
+usage(const char *fmt, ...) 
 {
+       if (fmt) {
+               va_list ap;
+               va_start(ap, fmt);
+               fprintf(stderr, "%s: ", getprogname());
+               vfprintf(stderr, fmt, ap);
+               fputc('\n', stderr);
+               va_end(ap);
+       }
+
        fprintf(stderr, "Usage: %s [-dnosvx] [-w timeout] lockfile|lockdir "
            "[-c command]|command ...\n\t%s [-dnsuvx] [-w timeout] lockfd\n",
            getprogname(), getprogname());
        exit(EXIT_FAILURE);
 }
 
-static __dead void
+static void
 sigalrm(int sig)
 {
        timeout_expired++;
@@ -106,6 +115,21 @@
        }
 }
 
+static char
+lockchar(int l)
+{
+       switch (l & ~LOCK_NB) {
+       case LOCK_SH:
+               return 's';
+       case LOCK_EX:
+               return 'x';
+       case LOCK_UN:
+               return 'u';
+       default:
+               return '*';
+       }
+}
+
 static char *
 cmdline(char **av)
 {
@@ -130,6 +154,7 @@
        int cls = 0;
        int fd = -1;
        int debug = 0;
+       int verbose = 0;
        char *mcargv[] = {
            __UNCONST(_PATH_BSHELL), __UNCONST("-c"), NULL, NULL
        };
@@ -145,16 +170,22 @@
                        debug++;
                        break;
                case 'x':
-                       lock = LOCK_EX | (lock & ~LOCK_NB);
+                       if (lock & ~LOCK_NB)
+                               goto badlock;
+                       lock |= LOCK_EX;
                        break;
                case 'n':
                        lock |= LOCK_NB;
                        break;
                case 's':
-                       lock = LOCK_SH | (lock & ~LOCK_NB);
+                       if (lock & ~LOCK_NB)
+                               goto badlock;
+                       lock |= LOCK_SH;
                        break;
                case 'u':
-                       lock = LOCK_UN | (lock & ~LOCK_NB);
+                       if (lock & ~LOCK_NB)
+                               goto badlock;
+                       lock |= LOCK_UN;
                        break;
                case 'w':
                        timeout = strtod(optarg, NULL);
@@ -166,7 +197,9 @@
                        cls = 1;
                        break;
                default:
-                       usage();
+                       usage("Invalid option '%c'", c);
+               badlock:
+                       usage("-%c can't be used with -%c", c, lockchar(lock));
                }
 
        argc -= optind;
@@ -174,21 +207,22 @@
 
        switch (argc) {
        case 0:
-               usage();
+               usage("Missing lock file argument");
        case 1:
                if (cls)
-                       usage();
+                       usage("Close is valid only for descriptors");
                fd = strtol(argv[0], NULL, 0);  // XXX: error checking
                if (debug)
                        fprintf(stderr, "descriptor %s lock %s\n",
                            argv[0], lock2name(lock));
-               if (lock == LOCK_UN)
-                       usage();
        default:
+               if ((lock & LOCK_NB) == LOCK_UN)
+                       usage("Unlock is only valid for descriptors");
                if (strcmp(argv[1], "-c") == 0 ||
                    strcmp(argv[1], "--command") == 0) {
                        if (argc == 2)
-                               usage();
+                               usage("Missing argument to %s", strcmp(argv[1],
+                                   "-c") == 0 ? "-c" : "--command");
                        mcargv[2] = argv[2];
                        cmdargv = mcargv;
                } else