gash/gash/built-ins/umask.scm

55 lines
1.7 KiB
Scheme

;;; Gash -- Guile As SHell
;;; Copyright © 2018, 2020 Timothy Sample <samplet@ngyro.com>
;;;
;;; 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/>.
(define-module (gash built-ins umask)
#:use-module (gash compat)
#:use-module (ice-9 match))
;;; Commentary:
;;;
;;; The 'umask' utility.
;;;
;;; Code:
(define (umask->octal-string mask)
(let* ((octal (number->string mask 8))
(pad-count (- 4 (string-length octal)))
(pad (make-string pad-count #\0)))
(string-append pad octal)))
(define (main . args)
(match args
(()
(format #t "~a~%" (umask->octal-string (umask)))
EXIT_SUCCESS)
((mask)
(let ((n (string->number mask 8)))
(cond
((and n (integer? n) (>= n 0) (< n 512))
(umask n)
EXIT_SUCCESS)
(else
(format (current-error-port)
"~a: umask: Invalid option ~s.~%"
(car (program-arguments)) mask)
EXIT_FAILURE))))
(_ (format (current-error-port)
"~a: umask: Invalid options ~s.~%"
(car (program-arguments)) args)
EXIT_FAILURE)))