dmesg: improve err handling code

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

diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index a3d95f1b77773f3670d942b37df8587637a66ed7..1c5de2a5e4a11206422057841ccae7f331f9067d 100644 (file)
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -985,9 +985,10 @@ static int read_kmsg(struct dmesg_control *ctl)
 int main(int argc, char *argv[])
 {
        char *buf = NULL;
-       ssize_t  n, r;
        int  c;
        int  console_level = 0;
+       int  klog_rc = 0;
+       ssize_t n;
        static struct dmesg_control ctl = {
                .filename = NULL,
                .action = SYSLOG_ACTION_READ_ALL,
@@ -1127,8 +1128,6 @@ int main(int argc, char *argv[])
        }
        argc -= optind;
        argv += optind;
-       n = 0;
-       r = 0;
 
        if (argc > 1)
                usage(stderr);
@@ -1149,32 +1148,32 @@ int main(int argc, char *argv[])
                if (ctl.method == DMESG_METHOD_KMSG && init_kmsg(&ctl) != 0)
                        ctl.method = DMESG_METHOD_SYSLOG;
 
-               r = read_buffer(&ctl, &buf);
-               if (r > 0)
-                       print_buffer(&ctl, buf, r);
+               n = read_buffer(&ctl, &buf);
+               if (n > 0)
+                       print_buffer(&ctl, buf, n);
                if (!ctl.mmap_buff)
                        free(buf);
+               if (n < 0)
+                       err(EXIT_FAILURE, _("read kernel buffer failed"));
+               if (ctl.kmsg >= 0)
+                       close(ctl.kmsg);
                break;
        case SYSLOG_ACTION_CLEAR:
        case SYSLOG_ACTION_CONSOLE_OFF:
        case SYSLOG_ACTION_CONSOLE_ON:
-               n = klogctl(ctl.action, NULL, 0);
+               klog_rc = klogctl(ctl.action, NULL, 0);
                break;
        case SYSLOG_ACTION_CONSOLE_LEVEL:
-               n = klogctl(ctl.action, NULL, console_level);
+               klog_rc = klogctl(ctl.action, NULL, console_level);
                break;
        default:
                errx(EXIT_FAILURE, _("unsupported command"));
                break;
        }
 
-       if (ctl.kmsg >= 0)
-               close(ctl.kmsg);
 
-       if (n < 0)
+       if (klog_rc)
                err(EXIT_FAILURE, _("klogctl failed"));
-       if (r < 0)
-               err(EXIT_FAILURE, _("read_buffer failed"));
 
        return EXIT_SUCCESS;
 }