guix-devel/guix/scripts/hash.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013, 2014, 2016 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.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 hash)
#:use-module (guix serialization)
#:use-module (guix ui)
#:use-module (guix scripts)
#:use-module (guix utils)
#:use-module (ice-9 binary-ports)
#:use-module (rnrs files)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-37)
#:export (guix-hash))
;;;
;;; 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 (_ "
-x, --exclude-vcs exclude version control directories"))
(format #t (_ "
-f, --format=FMT write the hash in the given format"))
(format #t (_ "
-r, --recursive compute the hash on FILE recursively"))
(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 '(#\x "exclude-vcs") #f #f
(lambda (opt name arg result)
(alist-cons 'exclude-vcs? #t result)))
(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 '(#\r "recursive") #f #f
(lambda (opt name arg result)
(alist-cons 'recursive? #t 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")))))
;;;
;;; 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))
(define (vcs-file? file stat)
(case (stat:type stat)
((directory)
(member (basename file) '(".bzr" ".git" ".hg" ".svn" "CVS")))
(else
#f)))
(let* ((opts (parse-options))
(args (filter-map (match-lambda
(('argument . value)
value)
(_ #f))
(reverse opts)))
(fmt (assq-ref opts 'format))
(select? (if (assq-ref opts 'exclude-vcs?)
(negate vcs-file?)
(const #t))))
(define (file-hash file)
;; Compute the hash of FILE.
;; Catch and gracefully report possible '&nar-error' conditions.
(with-error-handling
(if (assoc-ref opts 'recursive?)
(let-values (((port get-hash) (open-sha256-port)))
(write-file file port #:select? select?)
(force-output port)
(get-hash))
(call-with-input-file file port-sha256))))
(match args
((file)
(catch 'system-error
(lambda ()
(format #t "~a~%" (fmt (file-hash file))))
(lambda args
(leave (_ "~a~%")
(strerror (system-error-errno args))))))
(x
(leave (_ "wrong number of arguments~%"))))))