dmesg: refactoring - cleanup read buffer code

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

diff --git a/sys-utils/dmesg.c b/sys-utils/dmesg.c
index e4a8cffa363c8f4fd712be831d737f3c58da56f5..a291857a63c9d6d5178520527c1485e69377e5f4 100644 (file)
--- a/sys-utils/dmesg.c
+++ b/sys-utils/dmesg.c
@@ -74,6 +74,36 @@ static int get_buffer_size()
        return n > 0 ? n : 0;
 }
 
+static int read_buffer(char **buf, size_t bufsize, int clear)
+{
+       size_t sz;
+       int rc = -1;
+       int cmd = clear ? SYSLOG_ACTION_READ_CLEAR :
+                         SYSLOG_ACTION_READ_ALL;
+
+       if (bufsize) {
+               sz = bufsize + 8;
+               *buf = xmalloc(sz * sizeof(char));
+               rc = klogctl(cmd, *buf, sz);
+       } else {
+               sz = 16392;
+               while (1) {
+                       *buf = xmalloc(sz * sizeof(char));
+                       rc = klogctl(SYSLOG_ACTION_READ_ALL, *buf, sz);
+                       if (rc != sz || sz > (1 << 28))
+                               break;
+                       free(*buf);
+                       *buf = NULL;
+                       sz *= 4;
+               }
+
+               if (rc > 0 && clear)
+                       rc = klogctl(SYSLOG_ACTION_READ_CLEAR, *buf, sz);
+       }
+
+       return rc;
+}
+
 static void print_buffer(const char *buf, size_t size, int flags)
 {
        int lastc = '\n';
@@ -98,7 +128,6 @@ static void print_buffer(const char *buf, size_t size, int flags)
 int main(int argc, char *argv[])
 {
        char *buf = NULL;
-       int  sz;
        int  bufsize = 0;
        int  n;
        int  c;
@@ -166,25 +195,7 @@ int main(int argc, char *argv[])
        if (!bufsize)
                bufsize = get_buffer_size();
 
-       if (bufsize) {
-               sz = bufsize + 8;
-               buf = xmalloc(sz * sizeof(char));
-               n = klogctl(cmd, buf, sz);
-       } else {
-               sz = 16392;
-               while (1) {
-                       buf = xmalloc(sz * sizeof(char));
-                       n = klogctl(SYSLOG_ACTION_READ_ALL, buf, sz);   /* read only */
-                       if (n != sz || sz > (1 << 28))
-                               break;
-                       free(buf);
-                       sz *= 4;
-               }
-
-               if (n > 0 && cmd == SYSLOG_ACTION_READ_CLEAR)
-                       n = klogctl(cmd, buf, sz);      /* read and clear */
-       }
-
+       n = read_buffer(&buf, bufsize, cmd == SYSLOG_ACTION_READ_CLEAR);
        if (n < 0)
                err(EXIT_FAILURE, _("klogctl failed"));