ipcmk: fix error codes and error messages

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/ipcmk.c b/sys-utils/ipcmk.c
index de50888e7e6797bfa215f1606ac2e0ea7ed2ce0a..98ad02d02ed781001357df0a248a05b2a6cbde6b 100644 (file)
--- a/sys-utils/ipcmk.c
+++ b/sys-utils/ipcmk.c
@@ -2,6 +2,7 @@
  *  ipcmk.c - used to create ad-hoc IPC segments
  *
  *  Copyright (C) 2008 Hayden A. James (hayden.james@gmail.com)
+ *  Copyright (C) 2008 Karel Zak <kzak@redhat.com>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -22,6 +23,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <err.h>
 #include <time.h>
 
 #include <unistd.h>
@@ -31,6 +33,8 @@
 #include <sys/sem.h>
 #include <sys/msg.h>
 
+static const char *progname;
+
 key_t createKey(void)
 {
        srandom( time( NULL ) );
@@ -73,9 +77,17 @@ int createSem(int nsems, int permission)
        return result;
 }
 
-void usage(char *progname)
+void usage(int rc)
 {
-          fprintf(stderr, "usage: %s [-M size] [-S nsems] [-Q] [-p permission]\n", progname);
+       printf("\nUsage: %s [options]\n\n", progname);
+       printf(
+       "  -M <size>     create shared memory segment of size <size>\n"
+       "  -S <nsems>    create semaphore array with <nsems> elements\n"
+       "  -Q            create message queue\n"
+        "  -p <mode>     permission for the resource (default is 0644)\n");
+       printf("\nFor more information see ipcmk(1).\n\n");
+
+       exit(rc);
 }
 
 int main(int argc, char **argv)
@@ -84,10 +96,13 @@ int main(int argc, char **argv)
        int opt;
        size_t size = 0;
        int nsems = 0;
-
        int doShm = 0, doMsg = 0, doSem = 0;
 
-       while((opt = getopt(argc, argv, "M:QS:p:")) != -1) {
+       progname = program_invocation_short_name;
+       if (!progname)
+               progname = "ipcmk";
+
+       while((opt = getopt(argc, argv, "hM:QS:p:")) != -1) {
                switch(opt) {
                case 'M':
                        size = atoi(optarg);
@@ -103,38 +118,41 @@ int main(int argc, char **argv)
                case 'p':
                        permission = strtoul(optarg, NULL, 8);
                        break;
+               case 'h':
+                       usage(EXIT_SUCCESS);
+                       break;
                default:
                        doShm = doMsg = doSem = 0;
                        break;
                }
        }
 
+       if(!doShm && !doMsg && !doSem)
+               usage(EXIT_FAILURE);
+
        if (doShm) {
                int shmid;
                if (-1 == (shmid = createShm(size, permission)))
-                       fprintf(stderr, "%s\n", strerror(errno));
+                       err(EXIT_FAILURE, "create share memory failed");
                else
-                       fprintf(stdout, "%s%d\n", "Shared memory id: ", shmid);
+                       printf("Shared memory id: %d\n", shmid);
        }
 
        if (doMsg) {
                int msgid;
                if (-1 == (msgid = createMsg(permission)))
-                       fprintf(stderr, "%s\n", strerror(errno));
+                       err(EXIT_FAILURE, "create message queue failed");
                else
-                       fprintf(stdout, "%s%d\n", "Message queue id: ", msgid);
+                       printf("Message queue id: %d\n", msgid);
        }
 
        if (doSem) {
                int semid;
                if (-1 == (semid = createSem(nsems, permission)))
-                       fprintf(stderr, "%s\n", strerror(errno));
+                       err(EXIT_FAILURE, "create semaphore failed");
                else
-                       fprintf(stdout, "%s%d\n", "Semaphore id: ", semid);
+                       printf("Semaphore id: %d\n", semid);
        }
 
-       if(!doShm && !doMsg && !doSem)
-               usage(argv[0]);
-
-       return 0;
+       return EXIT_SUCCESS;
 }