Re: [PATCH] commands/hashsum: Allow to store hash in variable

[Avnish Chouhan <avnish@linux.ibm.com>]

On 2025-10-10 21:30, grub-devel-request@gnu.org wrote:
> Message: 1
> Date: Thu, 9 Oct 2025 22:34:31 +0200
> From: "D.-E. Divernois" <d-e.divernois@musiciel.fr>
> To: grub-devel@gnu.org
> Subject: [PATCH] commands/hashsum: Allow to store hash in variable
> Message-ID: <cfe89b2a-e419-4997-87ce-bb5aec2e6746@musiciel.fr>
> Content-Type: text/plain; charset=UTF-8; format=flowed
> 

Hi,

Could you please give brief details about your patch here!
And resend the patch as per GNU coding style and standards.

Thank you!

Regards,
Avnish Chouhan

> Signed-off-by: David-Emmanuel Divernois <d-e.divernois@musiciel.fr>
> ---
> docs/grub.texi | 5 +++-
> grub-core/commands/hashsum.c | 46 +++++++++++++++++++++++++++++-------
> 2 files changed, 41 insertions(+), 10 deletions(-)
> 
> diff --git a/docs/grub.texi b/docs/grub.texi
> index b81eb1d93..7660ba3f7 100644
> --- a/docs/grub.texi
> +++ b/docs/grub.texi
> @@ -7376,7 +7376,7 @@ Otherwise, the computer is shut down using APM on
> that target.
> @node hashsum
> @subsection hashsum
> -@deffn Command hashsum @option{--hash} hash @option{--keep-going}
> @option{--uncompress} @option{--check} file [@option{--prefix} 
> dir]|file
> @dots{}
> +@deffn Command hashsum @option{--hash} hash @option{--keep-going}
> @option{--uncompress} [@option{--set} var] @option{--check} file
> [@option{--prefix} dir]|file @dots{}
> Compute or verify file hashes. Hash type is selected with option
> @option{--hash}.
> Supported hashes are: @samp{adler32}, @samp{crc64}, @samp{crc32},
> @samp{crc32rfc1510}, @samp{crc24rfc2440}, @samp{md4}, @samp{md5},
> @@ -7387,6 +7387,9 @@ Option @option{--uncompress} uncompresses files
> before computing hash.
> When list of files is given, hash of each file is computed and printed,
> followed by file name, each file on a new line.
> +When option @option{--set} is given, only one file is allowed and its 
> hash
> +is assigned to variable @var{var}.
> +
> When option @option{--check} is given, it points to a file that 
> contains
> list of @var{hash name} pairs in the same format as used by UNIX
> @command{md5sum} command. Option @option{--prefix}
> diff --git a/grub-core/commands/hashsum.c 
> b/grub-core/commands/hashsum.c
> index b6f8e3d1a..fb632e69c 100644
> --- a/grub-core/commands/hashsum.c
> +++ b/grub-core/commands/hashsum.c
> @@ -36,6 +36,8 @@ static const struct grub_arg_option options[] = {
> ARG_TYPE_STRING},
> {"keep-going", 'k', 0, N_("Don't stop after first error."), 0, 0},
> {"uncompress", 'u', 0, N_("Uncompress file before checksumming."), 0, 
> 0},
> + {"set", 's', 0, N_("Store the value in the given variable name."),
> N_("VAR"),
> + ARG_TYPE_STRING},
> {0, 0, 0, 0, 0, 0}
> };
> @@ -210,6 +212,7 @@ grub_cmd_hashsum (struct grub_extcmd_context *ctxt,
> struct grub_arg_list *state = ctxt->state;
> const char *hashname = NULL;
> const char *prefix = NULL;
> + const char *variable = NULL;
> const gcry_md_spec_t *hash;
> unsigned i;
> int keep = state[3].set;
> @@ -235,6 +238,13 @@ grub_cmd_hashsum (struct grub_extcmd_context 
> *ctxt,
> if (state[2].set)
> prefix = state[2].arg;
> + if (state[5].set) {
> + variable = state[5].arg;
> + if (argc != 1)
> + return grub_error (GRUB_ERR_BAD_ARGUMENT,
> + "--set is only usable with a single file");
> + }
> +
> if (state[1].set)
> {
> if (argc != 0)
> @@ -272,9 +282,27 @@ grub_cmd_hashsum (struct grub_extcmd_context 
> *ctxt,
> unread++;
> continue;
> }
> - for (j = 0; j < hash->mdlen; j++)
> - grub_printf ("%02x", ((grub_uint8_t *) result)[j]);
> - grub_printf (" %s\n", args[i]);
> + if (variable)
> + {
> + char *hex_string = grub_malloc (hash->mdlen * 2 + 1);
> + if (hex_string)
> + {
> + for (j = 0; j < hash->mdlen; j++)
> + {
> + grub_snprintf (hex_string + j * 2, 3, "%02x",
> + ((grub_uint8_t *) result)[j]);
> + }
> + hex_string[hash->mdlen * 2] = '\0';
> + grub_env_set (variable, hex_string);
> + grub_free (hex_string);
> + }
> + }
> + else
> + {
> + for (j = 0; j < hash->mdlen; j++)
> + grub_printf ("%02x", ((grub_uint8_t *) result)[j]);
> + grub_printf (" %s\n", args[i]);
> + }
> }
> if (unread)
> @@ -288,7 +316,7 @@ static grub_extcmd_t cmd, cmd_md5, cmd_sha1,
> cmd_sha256, cmd_sha512, cmd_crc;
> GRUB_MOD_INIT(hashsum)
> {
> cmd = grub_register_extcmd ("hashsum", grub_cmd_hashsum, 0,
> - N_("-h HASH [-c FILE [-p PREFIX]] "
> + N_("-h HASH [-c FILE [-p PREFIX]] [-s VAR]"
> "[FILE1 [FILE2 ...]]"),
> /* TRANSLATORS: "hash checksum" is just to
> be a bit more precise, you can treat it as
> @@ -296,28 +324,28 @@ GRUB_MOD_INIT(hashsum)
> N_("Compute or check hash checksum."),
> options);
> cmd_md5 = grub_register_extcmd ("md5sum", grub_cmd_hashsum, 0,
> - N_("[-c FILE [-p PREFIX]] "
> + N_("[-c FILE [-p PREFIX]] [-s VAR]"
> "[FILE1 [FILE2 ...]]"),
> N_("Compute or check hash checksum."),
> options);
> cmd_sha1 = grub_register_extcmd ("sha1sum", grub_cmd_hashsum, 0,
> - N_("[-c FILE [-p PREFIX]] "
> + N_("[-c FILE [-p PREFIX]] [-s VAR]"
> "[FILE1 [FILE2 ...]]"),
> N_("Compute or check hash checksum."),
> options);
> cmd_sha256 = grub_register_extcmd ("sha256sum", grub_cmd_hashsum, 0,
> - N_("[-c FILE [-p PREFIX]] "
> + N_("[-c FILE [-p PREFIX]] [-s VAR]"
> "[FILE1 [FILE2 ...]]"),
> N_("Compute or check hash checksum."),
> options);
> cmd_sha512 = grub_register_extcmd ("sha512sum", grub_cmd_hashsum, 0,
> - N_("[-c FILE [-p PREFIX]] "
> + N_("[-c FILE [-p PREFIX]] [-s VAR]"
> "[FILE1 [FILE2 ...]]"),
> N_("Compute or check hash checksum."),
> options);
> cmd_crc = grub_register_extcmd ("crc", grub_cmd_hashsum, 0,
> - N_("[-c FILE [-p PREFIX]] "
> + N_("[-c FILE [-p PREFIX]] [-s VAR]"
> "[FILE1 [FILE2 ...]]"),
> N_("Compute or check hash checksum."),
> options);
> 
> --
> 2.51.0
> 
> 
> 
> 
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