[U-Boot] [PATCH] env: Provide programmatic equivalent to 'setenv -f'

[Joe Hershberger]

Hi James,

On Tue, Nov 19, 2019 at 11:32 AM James Byrne
<james.byrne at origamienergy.com> wrote:
>
> Add env_force() to provide an equivalent to 'setenv -f' that can be used
> programmatically.
>
> Also tighten up the definition of argv in _do_env_set() so that
> 'const char *' pointers are used.
>
> Signed-off-by: James Byrne <james.byrne at origamienergy.com>
>
> ---
>
>  cmd/nvedit.c  | 43 +++++++++++++++++++++++++++++--------------
>  include/env.h | 13 +++++++++++++
>  2 files changed, 42 insertions(+), 14 deletions(-)
>
> diff --git a/cmd/nvedit.c b/cmd/nvedit.c
> index 99a3bc57b1..1f363ba9f4 100644
> --- a/cmd/nvedit.c
> +++ b/cmd/nvedit.c
> @@ -221,10 +221,12 @@ DONE:
>   * Set a new environment variable,
>   * or replace or delete an existing one.
>   */
> -static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
> +static int _do_env_set(int flag, int argc, const char * const argv[],
> +                      int env_flag)
>  {
>         int   i, len;
> -       char  *name, *value, *s;
> +       const char *name;
> +       char *value, *s;
>         struct env_entry e, *ep;
>
>         debug("Initial value for argc=%d\n", argc);
> @@ -235,7 +237,7 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
>  #endif
>
>         while (argc > 1 && **(argv + 1) == '-') {
> -               char *arg = *++argv;
> +               const char *arg = *++argv;
>
>                 --argc;
>                 while (*++arg) {
> @@ -277,7 +279,7 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
>                 return 1;
>         }
>         for (i = 2, s = value; i < argc; ++i) {
> -               char *v = argv[i];
> +               const char *v = argv[i];
>
>                 while ((*s++ = *v++) != '\0')
>                         ;
> @@ -299,18 +301,30 @@ static int _do_env_set(int flag, int argc, char * const argv[], int env_flag)
>         return 0;
>  }
>
> -int env_set(const char *varname, const char *varvalue)
> +static int do_programmatic_env_set(int argc, const char * const argv[])
>  {
> -       const char * const argv[4] = { "setenv", varname, varvalue, NULL };
> -
>         /* before import into hashtable */
>         if (!(gd->flags & GD_FLG_ENV_READY))
>                 return 1;
>
> -       if (varvalue == NULL || varvalue[0] == '\0')
> -               return _do_env_set(0, 2, (char * const *)argv, H_PROGRAMMATIC);
> -       else
> -               return _do_env_set(0, 3, (char * const *)argv, H_PROGRAMMATIC);
> +       if (!argv[argc - 1] || argv[argc - 1][0] == '\0')
> +               argc--;
> +
> +       return _do_env_set(0, argc, argv, H_PROGRAMMATIC);
> +}
> +
> +int env_set(const char *varname, const char *varvalue)
> +{
> +       const char * const argv[4] = {"setenv", varname, varvalue, NULL};
> +
> +       return do_programmatic_env_set(3, argv);
> +}
> +
> +int env_force(const char *varname, const char *varvalue)
> +{
> +       const char * const argv[5] = {"setenv", "-f", varname, varvalue, NULL};
> +
> +       return do_programmatic_env_set(4, argv);
>  }
>
>  /**
> @@ -382,7 +396,8 @@ static int do_env_set(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>         if (argc < 2)
>                 return CMD_RET_USAGE;
>
> -       return _do_env_set(flag, argc, argv, H_INTERACTIVE);
> +       return _do_env_set(flag, argc, (const char * const *)argv,
> +                          H_INTERACTIVE);
>  }
>
>  /*
> @@ -643,12 +658,12 @@ static int do_env_edit(cmd_tbl_t *cmdtp, int flag, int argc,
>         if (buffer[0] == '\0') {
>                 const char * const _argv[3] = { "setenv", argv[1], NULL };
>
> -               return _do_env_set(0, 2, (char * const *)_argv, H_INTERACTIVE);
> +               return _do_env_set(0, 2, _argv, H_INTERACTIVE);
>         } else {
>                 const char * const _argv[4] = { "setenv", argv[1], buffer,
>                         NULL };
>
> -               return _do_env_set(0, 3, (char * const *)_argv, H_INTERACTIVE);
> +               return _do_env_set(0, 3, _argv, H_INTERACTIVE);
>         }
>  }
>  #endif /* CONFIG_CMD_EDITENV */
> diff --git a/include/env.h b/include/env.h
> index b72239f6a5..37bbf1117d 100644
> --- a/include/env.h
> +++ b/include/env.h
> @@ -145,6 +145,19 @@ int env_get_yesno(const char *var);
>   */
>  int env_set(const char *varname, const char *value);
>
> +/**
> + * env_force() - forcibly set an environment variable
> + *
> + * This sets or deletes the value of an environment variable. It is the same
> + * as env_set(), except that the variable will be forcibly updated/deleted,
> + * even if it has access protection flags set.
> + *
> + * @varname: Variable to adjust
> + * @value: Value to set for the variable, or NULL or "" to delete the variable
> + * @return 0 if OK, 1 on error
> + */
> +int env_force(const char *varname, const char *varvalue);

Please call it env_force_set()

> +
>  /**
>   * env_get_ulong() - Return an environment variable as an integer value
>   *
> --
> 2.24.0
>
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