[PATCH v1 1/1] cmd: setexpr: add dec operation for converting variable to decimal

[Simon Glass]

Hi Roland,

On Tue, 22 Jun 2021 at 07:51, <roland.gaudig-oss at weidmueller.com> wrote:
>
> From: Roland Gaudig <roland.gaudig at weidmueller.com>
>
> This patch extends the setexpr command with a dec operator to
> convert an input value to decimal.
>
> Signed-off-by: Roland Gaudig <roland.gaudig at weidmueller.com>
> ---
>
>  cmd/setexpr.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/cmd/setexpr.c b/cmd/setexpr.c
> index e828be3970..2d4bee2182 100644
> --- a/cmd/setexpr.c
> +++ b/cmd/setexpr.c
> @@ -370,15 +370,16 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
>         int w;
>
>         /*
> -        * We take 3, 5, or 6 arguments:
> +        * We take 3, 4, 5, or 6 arguments:
>          * 3 : setexpr name value
> +        * 4 : setexpr name dec value
>          * 5 : setexpr name val1 op val2
>          *     setexpr name [g]sub r s
>          * 6 : setexpr name [g]sub r s t
>          */
>
>         /* > 6 already tested by max command args */
> -       if ((argc < 3) || (argc == 4))
> +       if (argc < 3)
>                 return CMD_RET_USAGE;
>
>         w = cmd_get_data_size(argv[0], 4);
> @@ -398,6 +399,13 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
>                 return ret;
>         }
>
> +       /* hexadecimal to decimal conversion: "setexpr name dec value" */
> +       if (argc == 4 && (strcmp(argv[2], "dec") == 0)) {
> +               w = cmd_get_data_size(argv[3], 4);
> +               a = get_arg(argv[3], w);
> +               return env_set_ulong(argv[1], a);
> +       }
> +
>         /* 5 or 6 args (6 args only with [g]sub) */
>  #ifdef CONFIG_REGEX
>         /*
> @@ -515,4 +523,8 @@ U_BOOT_CMD(
>         "setexpr name sub r s [t]\n"
>         "    - Just like gsub(), but replace only the first matching substring"
>  #endif
> +       "\n"
> +       "setexpr name dec [*]value\n"
> +       "    - set environment variable 'name' to the result of the decimal\n"
> +       "      conversion of [*]value.\n"
>  );
> --
> 2.25.1
>

This seems reasonable to me.

I have been thinking of introducing a prefix for decimal, perhaps
0m123 ? ('m' for deciMal).

Can you please add a test for this in test//cmd/setexpr.c and also,
how about adding something in doc/usage?

Regards,
Simon