3ad8f7757c
* gnu/installer/utils.scm (nearest-exact-integer): New exported procedure, (read-percentage): ditto, (run-shell-command): ditto.
64 lines
2.2 KiB
Scheme
64 lines
2.2 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
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;;; Copyright © 2018 Mathieu Othacehe <m.othacehe@gmail.com>
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;;;
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;;; This file is part of GNU Guix.
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;;;
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;;; GNU Guix is free software; you can redistribute it and/or modify it
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;;; under the terms of the GNU General Public License as published by
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;;; the Free Software Foundation; either version 3 of the License, or (at
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;;; your option) any later version.
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;;;
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;;; GNU Guix is distributed in the hope that it will be useful, but
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;;; WITHOUT ANY WARRANTY; without even the implied warranty of
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;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;;; GNU General Public License for more details.
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;;;
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;;; You should have received a copy of the GNU General Public License
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;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
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(define-module (gnu installer utils)
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#:use-module (guix utils)
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#:use-module (guix build utils)
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#:use-module (ice-9 rdelim)
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#:use-module (ice-9 regex)
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#:use-module (ice-9 textual-ports)
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#:export (read-lines
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read-all
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nearest-exact-integer
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read-percentage
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run-shell-command))
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(define* (read-lines #:optional (port (current-input-port)))
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"Read lines from PORT and return them as a list."
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(let loop ((line (read-line port))
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(lines '()))
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(if (eof-object? line)
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(reverse lines)
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(loop (read-line port)
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(cons line lines)))))
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(define (read-all file)
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"Return the content of the given FILE as a string."
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(call-with-input-file file
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get-string-all))
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(define (nearest-exact-integer x)
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"Given a real number X, return the nearest exact integer, with ties going to
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the nearest exact even integer."
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(inexact->exact (round x)))
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(define (read-percentage percentage)
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"Read PERCENTAGE string and return the corresponding percentage as a
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number. If no percentage is found, return #f"
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(let ((result (string-match "^([0-9]+)%$" percentage)))
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(and result
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(string->number (match:substring result 1)))))
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(define (run-shell-command command)
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(call-with-temporary-output-file
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(lambda (file port)
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(format port "~a~%" command)
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;; (format port "exit~%")
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(close port)
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(invoke "bash" "--init-file" file))))
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