[Qemu-devel] [PATCH v2] opts: produce valid command line in qemu_opts_print

[Qemu-devel] [PATCH v2] opts: produce valid command line in qemu_opts_print

[Kővágó, Zoltán]

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* do not quote string arguments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>
---

Change from v1:
* updated escaped_print as suggested by Markus

 block.c            |  2 +-
 util/qemu-option.c | 29 ++++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/block.c b/block.c
index 7e130cc..78a5304 100644
--- a/block.c
+++ b/block.c
@@ -3813,7 +3813,7 @@ void bdrv_img_create(const char *filename, const char *fmt,
     }
 
     if (!quiet) {
-        printf("Formatting '%s', fmt=%s", filename, fmt);
+        printf("Formatting '%s', fmt=%s ", filename, fmt);
         qemu_opts_print(opts, " ");
         puts("");
     }
diff --git a/util/qemu-option.c b/util/qemu-option.c
index efe9d27..e54ac0d 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -730,14 +730,35 @@ 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;
     }
@@ -750,13 +771,15 @@ 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;
     }
 }
 
-- 
2.4.5

Re: [Qemu-devel] [Qemu-block] [PATCH v2] opts: produce valid command line in qemu_opts_print

[Stefan Hajnoczi]

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On Fri, Jul 03, 2015 at 04:45:36PM +0200, Kővágó, Zoltán wrote:
> 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>
> ---
> 
> Change from v1:
> * updated escaped_print as suggested by Markus
> 
>  block.c            |  2 +-
>  util/qemu-option.c | 29 ++++++++++++++++++++++++++---
>  2 files changed, 27 insertions(+), 4 deletions(-)

Looks good but please fix qemu-iotests so the test suite keeps passing:

  $ make && cd tests/qemu-iotests && ./check -qcow2

The test fixes must be in the same commit so the git commit history
remains bisectable.

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