[PATCH v1] env: setenv add resolve value option

[Simon Glass]

Hi Artem,

On Tue, 2 Nov 2021 at 01:19, Artem Lapkin <email2tema at gmail.com> wrote:
>
> Add possibility setup env variable with additional resolving vars inside
> value.
>
> Usage examples
>
> => setenv a hello
> => setenv b world
> => setenv c '${a} ${b}'
> => setenv -r d '${c}! ${a}...'
> => printenv d
> d=hello world! hello...
>
> /* internal usage example */
> env_resolve("d", "${c}! ${a}...");
> /* d="hello world! hello..." */
>
> Notes
>
> Resolving works only for ${var} "bracket" and didn't workd for
> "unbracket" $var

how come?

>
> => setenv -r d '$c! $a...'
> => printenv d
> d=$c! $a...
>
> Signed-off-by: Artem Lapkin <art at khadas.com>
> ---
>  cmd/nvedit.c       | 42 +++++++++++++++++++++++++++++++++++++++++-
>  include/_exports.h |  1 +
>  include/env.h      | 11 +++++++++++
>  include/exports.h  |  1 +
>  4 files changed, 54 insertions(+), 1 deletion(-)

See also this old patch:

https://patchwork.ozlabs.org/project/uboot/patch/1449255744-25787-1-git-send-email-nm@ti.com/

>
> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> index 3bb6e764c0..6608932dc0 100644
> --- a/cmd/nvedit.c
> +++ b/cmd/nvedit.c
> @@ -229,6 +229,7 @@ static int _do_env_set(int flag, int argc, char *const argv[], int env_flag)
>         int   i, len;
>         char  *name, *value, *s;
>         struct env_entry e, *ep;
> +       bool  resolve = 0;
>
>         debug("Initial value for argc=%d\n", argc);
>
> @@ -246,6 +247,9 @@ static int _do_env_set(int flag, int argc, char *const argv[], int env_flag)
>                         case 'f':               /* force */
>                                 env_flag |= H_FORCE;
>                                 break;
> +                       case 'r':               /* resolve */
> +                               resolve = 1;
> +                               break;
>                         default:
>                                 return CMD_RET_USAGE;
>                         }
> @@ -291,6 +295,26 @@ static int _do_env_set(int flag, int argc, char *const argv[], int env_flag)
>         if (s != value)
>                 *--s = '\0';
>
> +       /*
> +        * deep resolve value vars
> +        */

single-line comment style is /*... */

> +       if (resolve) {
> +               int max_loop = 32;
> +               char value2[CONFIG_SYS_CBSIZE];
> +
> +               do {
> +                       cli_simple_process_macros(value, value2, CONFIG_SYS_CBSIZE);
> +                       if (!strcmp(value, value2))
> +                               break;
> +                       value = realloc(value, strlen(value2));

strdup() ?

> +                       if (!value) {
> +                               printf("## Can't realloc %d bytes\n", len);
> +                               return 1;
> +                       }
> +                       strcpy(value, value2);
> +               } while (max_loop--);
> +       }
> +
>         e.key   = name;
>         e.data  = value;
>         hsearch_r(e, ENV_ENTER, &ep, &env_htab, env_flag);
> @@ -304,6 +328,20 @@ static int _do_env_set(int flag, int argc, char *const argv[], int env_flag)
>         return 0;
>  }
>
> +int env_resolve(const char *varname, const char *varvalue)
> +{
> +       const char * const argv[5] = { "setenv", "-r", varname, varvalue, NULL };
> +
> +       /* before import into hashtable */
> +       if (!(gd->flags & GD_FLG_ENV_READY))
> +               return 1;
> +
> +       if (!varvalue || varvalue[0] == '\0')

Could put that in a var to avoid repeating in the next 3 lines:

> +               return _do_env_set(0, 3, (char * const *)argv, H_PROGRAMMATIC);
> +       else
> +               return _do_env_set(0, 4, (char * const *)argv, H_PROGRAMMATIC);
> +}
> +
>  int env_set(const char *varname, const char *varvalue)
>  {
>         const char * const argv[4] = { "setenv", varname, varvalue, NULL };
> @@ -1371,7 +1409,9 @@ U_BOOT_CMD_COMPLETE(
>         "setenv [-f] name value ...\n"
>         "    - [forcibly] set environment variable 'name' to 'value ...'\n"
>         "setenv [-f] name\n"
> -       "    - [forcibly] delete environment variable 'name'",
> +       "    - [forcibly] delete environment variable 'name'\n"
> +       "setenv [-r] name value ...\n"
> +       "    - [resolve] resolve 'value ...' to environment variable\n",
>         var_complete
>  );
>
> diff --git a/include/_exports.h b/include/_exports.h
> index 8030d70c0b..86bc07f051 100644
> --- a/include/_exports.h
> +++ b/include/_exports.h
> @@ -32,6 +32,7 @@
>         EXPORT_FUNC(do_reset, int, do_reset, struct cmd_tbl *,
>                     int , int , char * const [])
>         EXPORT_FUNC(env_get, char  *, env_get, const char*)
> +       EXPORT_FUNC(env_resolve, int, env_resolve, const char *, const char *)
>         EXPORT_FUNC(env_set, int, env_set, const char *, const char *)
>         EXPORT_FUNC(simple_strtoul, unsigned long, simple_strtoul,
>                     const char *, char **, unsigned int)
> diff --git a/include/env.h b/include/env.h
> index ee5e30d036..c4efc5b7e5 100644
> --- a/include/env.h
> +++ b/include/env.h
> @@ -133,6 +133,17 @@ int env_get_f(const char *name, char *buf, unsigned int len);
>   */
>  int env_get_yesno(const char *var);
>
> +/**
> + * env_resolve() - resolve to environment variable
> + *
> + * Same as env_set but make deep resolve for variable
> + *
> + * @varname: Variable to adjust
> + * @value: Value to resolve for the variable, or NULL or "" to delete the variable
> + * @return 0 if OK, 1 on error
> + */
> +int env_resolve(const char *varname, const char *value);
> +
>  /**
>   * env_set() - set an environment variable
>   *
> diff --git a/include/exports.h b/include/exports.h
> index 550cafdc7a..a54b997988 100644
> --- a/include/exports.h
> +++ b/include/exports.h
> @@ -44,6 +44,7 @@ int vprintf(const char *, va_list);
>  unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base);
>  int strict_strtoul(const char *cp, unsigned int base, unsigned long *res);
>  char *env_get(const char *name);
> +int env_resolve(const char *varname, const char *value);

please add function comment

>  int env_set(const char *varname, const char *value);
>  long simple_strtol(const char *cp, char **endp, unsigned int base);
>  int strcmp(const char *cs, const char *ct);
> --
> 2.25.1
>

Can you please add to the env tests?

test/py/tests/test_env.py
Regards,
Simon