The @code{sha256} field specifies the expected SHA256 hash of the file
being downloaded. It is mandatory, and allows Guix to check the
integrity of the file. The @code{(base32 @dots{})} form introduces the
-base32 representation of the hash. A convenient way to obtain this
-information is with the @code{guix download} tool.
+base32 representation of the hash. You can obtain this information with
+the @code{guix hash} (@pxref{Invoking guix hash}) and @code{guix
+download} tools.
@item
@cindex GNU Build System
@menu
* Invoking guix build:: Building packages from the command line.
+* Invoking guix hash:: Computing the cryptographic hash of a file.
@end menu
@node Invoking guix build
module, and to the @code{build-derivations} procedure of the @code{(guix
store)} module.
+@node Invoking guix hash
+@section Invoking @command{guix hash}
+
+The @command{guix hash} command allows to check the integrity of a file.
+It is primarily a convenience tool for anyone contributing to the
+distribution: it computes the cryptographic hash of a file, which can be
+used in the definition of a package (@pxref{Defining Packages}).
+
+The general syntax is:
+
+@example
+guix hash @var{option} @var{file}
+@end example
+
+@command{guix hash} has the following option:
+
+@table @code
+
+@item --format=@var{fmt}
+@itemx -f @var{fmt}
+Write the hash in the given format.
+
+Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
+(@code{hex} and @code{hexadecimal} can be used as well).
+
+If the @option{--format} option is not specified, @command{guix hash}
+will output the hash in @code{nix-base32}. This representation is used
+in the definitions of packages.
+
+@end table
+
@c *********************************************************************
@node GNU Distribution
@chapter GNU Distribution
--- /dev/null
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix scripts hash)
+ #:use-module (guix base32)
+ #:use-module (guix ui)
+ #:use-module (guix utils)
+ #:use-module (rnrs io ports)
+ #:use-module (rnrs files)
+ #:use-module (ice-9 match)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:use-module (srfi srfi-37)
+ #:export (guix-hash))
+
+\f
+;;;
+;;; Command-line options.
+;;;
+
+(define %default-options
+ ;; Alist of default option values.
+ `((format . ,bytevector->nix-base32-string)))
+
+(define (show-help)
+ (display (_ "Usage: guix hash [OPTION] FILE
+Return the cryptographic hash of FILE.
+
+Supported formats: 'nix-base32' (default), 'base32', and 'base16'
+('hex' and 'hexadecimal' can be used as well).\n"))
+ (format #t (_ "
+ -f, --format=FMT write the hash in the given format"))
+ (newline)
+ (display (_ "
+ -h, --help display this help and exit"))
+ (display (_ "
+ -V, --version display version information and exit"))
+ (newline)
+ (show-bug-report-information))
+
+(define %options
+ ;; Specification of the command-line options.
+ (list (option '(#\f "format") #t #f
+ (lambda (opt name arg result)
+ (define fmt-proc
+ (match arg
+ ("nix-base32"
+ bytevector->nix-base32-string)
+ ("base32"
+ bytevector->base32-string)
+ ((or "base16" "hex" "hexadecimal")
+ bytevector->base16-string)
+ (x
+ (leave (_ "unsupported hash format: ~a~%")
+ arg))))
+
+ (alist-cons 'format fmt-proc
+ (alist-delete 'format result))))
+
+ (option '(#\h "help") #f #f
+ (lambda args
+ (show-help)
+ (exit 0)))
+ (option '(#\V "version") #f #f
+ (lambda args
+ (show-version-and-exit "guix hash")))))
+
+
+\f
+;;;
+;;; Entry point.
+;;;
+
+(define (guix-hash . args)
+ (define (parse-options)
+ ;; Return the alist of option values.
+ (args-fold args %options
+ (lambda (opt name arg result)
+ (leave (_ "unrecognized option: ~a~%")
+ name))
+ (lambda (arg result)
+ (alist-cons 'argument arg result))
+ %default-options))
+
+ (let* ((opts (parse-options))
+ (args (filter-map (match-lambda
+ (('argument . value)
+ value)
+ (_ #f))
+ (reverse opts)))
+ (fmt (assq-ref opts 'format)))
+
+ (match args
+ ((file)
+ (catch 'system-error
+ (lambda ()
+ (format #t "~a~%"
+ (call-with-input-file file
+ (compose fmt sha256 get-bytevector-all))))
+ (lambda args
+ (leave (_ "~a~%")
+ (strerror (system-error-errno args))))))
+ (_
+ (leave (_ "wrong number of arguments~%"))))))
HCoop / jackhill / guix / guix.git / commitdiff