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

[Markus Armbruster]

"Kővágó, Zoltán" <address@hidden> writes:

> 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 * do not quote string arguments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 <address@hidden>
> ---
>
> Changes from patch submitted as part of `qapi flattening':
> * no longer tries to do proper escaping for the shell
>
>  block.c            |  2 +-
>  util/qemu-option.c | 30 +++++++++++++++++++++++++++---
>  2 files changed, 28 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..55ef172 100644
> --- a/util/qemu-option.c
> +++ b/util/qemu-option.c
> @@ -730,14 +730,36 @@ 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)

Have you searched the tree for existing code doing this?

> +{
> +    const char *ptr;
> +
> +    for (ptr = value; *ptr; ++ptr) {
> +        if (*ptr == ',') {
> +            printf(",,");
> +        } else {
> +            putchar(*ptr);
> +        }
> +    }

Slightly simpler:

        if (*ptr == ',') {
            putchar(',');
        }
        putchar(*ptr);

Matter of taste.

> +}
> +
> +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 +772,15 @@ 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;
>      }
>  }

Reviewed-by: Markus Armbruster <address@hidden>