opts: produce valid command line in qemu_opts_print

This will let us print options in a format that the user would actually
write it on the command line (foo=bar,baz=asd,etc=def), without
prepending a spurious comma at the beginning of the list, or quoting
values unnecessarily.  This patch provides the following changes:
* write and id=, if the option has an id
* do not print separator before the first element
* do not quote string arguments
* properly escape commas (,) for QEMU

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

1 files changed, 26 insertions, 3 deletions

diff --git a/util/qemu-option.c b/util/qemu-option.c
index efd6f02..b1fb57c 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -735,14 +735,35 @@ void qemu_opts_del(QemuOpts *opts)
     g_free(opts);
 }
 
-void qemu_opts_print(QemuOpts *opts, const char *sep)
+/* print value, escaping any commas in value */
+static void escaped_print(const char *value)
+{
+    const char *ptr;
+
+    for (ptr = value; *ptr; ++ptr) {
+        if (*ptr == ',') {
+            putchar(',');
+        }
+        putchar(*ptr);
+    }
+}
+
+void qemu_opts_print(QemuOpts *opts, const char *separator)
 {
     QemuOpt *opt;
     QemuOptDesc *desc = opts->list->desc;
+    const char *sep = "";
+
+    if (opts->id) {
+        printf("id=%s", opts->id); /* passed id_wellformed -> no commas */
+        sep = separator;
+    }
 
     if (desc[0].name == NULL) {
         QTAILQ_FOREACH(opt, &opts->head, next) {
-            printf("%s%s=\"%s\"", sep, opt->name, opt->str);
+            printf("%s%s=", sep, opt->name);
+            escaped_print(opt->str);
+            sep = separator;
         }
         return;
     }
@@ -755,13 +776,15 @@ void qemu_opts_print(QemuOpts *opts, const char *sep)
             continue;
         }
         if (desc->type == QEMU_OPT_STRING) {
-            printf("%s%s='%s'", sep, desc->name, value);
+            printf("%s%s=", sep, desc->name);
+            escaped_print(value);
         } else if ((desc->type == QEMU_OPT_SIZE ||
                     desc->type == QEMU_OPT_NUMBER) && opt) {
             printf("%s%s=%" PRId64, sep, desc->name, opt->value.uint);
         } else {
             printf("%s%s=%s", sep, desc->name, value);
         }
+        sep = separator;
     }
 }