util/cutils: Return qemu_strtosz*() error and value separately

This makes qemu_strtosz(), qemu_strtosz_mebi() and
qemu_strtosz_metric() similar to qemu_strtoi64(), except negative
values are rejected.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-23-git-send-email-armbru@redhat.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c
index 973eb94774..01a6dc6fbc 100644
--- a/qemu-io-cmds.c
+++ b/qemu-io-cmds.c
@@ -137,10 +137,14 @@ static char **breakline(char *input, int *count)
 
 static int64_t cvtnum(const char *s)
 {
-    int64_t ret;
+    int err;
+    int64_t value;
 
-    ret = qemu_strtosz(s, NULL);
-    return ret;
+    err = qemu_strtosz(s, NULL, &value);
+    if (err < 0) {
+        return err;
+    }
+    return value;
 }
 
 static void print_cvtnum_err(int64_t rc, const char *arg)