gash/gash/commands/touch.scm

86 lines
2.9 KiB
Scheme

;;; Gash -- Guile As SHell
;;; Copyright © 2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
;;;
;;; This file is part of Gash.
;;;
;;; Gash 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.
;;;
;;; Gash 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 Gash. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
(define-module (gash commands touch)
#:use-module (ice-9 getopt-long)
#:use-module (ice-9 match)
#:use-module (ice-9 receive)
#:use-module (ice-9 regex)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-9 gnu)
#:use-module (srfi srfi-26)
#:use-module (gash config)
#:use-module (gash guix-utils)
#:use-module (gash shell-utils)
#:export (
touch
))
(define (create-or-touch file time)
(let ((exists? (file-exists? file)))
(when (not exists?) (with-output-to-file file (cut display "")))
(cond (time (utime file time time))
(exists? (let ((time (current-time)))
(utime file time time))))))
(define (parse-date string)
(if (string-prefix? "@" string)
(string->number (substring string 1))
(error (format #f "touch: cannot parse date:~a\n" string))))
(define (touch . args)
(let* ((option-spec
'((date (single-char #\d) (value #t))
(help (single-char #\h))
(reference (single-char #\r) (value #t))
(version (single-char #\V))))
(options (getopt-long args option-spec))
(help? (option-ref options 'help #f))
(version? (option-ref options 'version #f))
(date (option-ref options 'date #f))
(reference (option-ref options 'reference #f))
(files (option-ref options '() '()))
(usage? (and (not help?) (null? files))))
(cond (version? (format #t "touch (GASH) ~a\n" %version) (exit 0))
((or help? usage?) (format (if usage? (current-error-port) #t)
"\
Usage: touch [OPTION]... FILE...
Update the access and modification times of each FILE to the current time.
Options:
-d, --date=DATE parse DATE and use it instead of current time
--help display this help and exit
-r, --reference=FILE use FILE's times instead of current time
--version output version information and exit
Each MODE is of the form '[ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=][0-7]+'.
")
(exit (if usage? 2 0)))
(else
(let ((time (and=> date parse-date)))
(for-each (cut create-or-touch <> time) files))))))
(define main touch)