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bournish: Add 'wc' command.

* guix/build/bournish.scm (lines+chars, file-exists?*, wc-print)
(wc-l-print, wc-c-print, wc-command, wc-command-implementation)
(wc-l-command-implementation, wc-c-command-implementation): New procedures.
(%commands): Add 'wc'.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>
version-0.11.0
Efraim Flashner 6 years ago
committed by Ludovic Courtès
parent
commit
bae06364c1
No known key found for this signature in database GPG Key ID: 90B11993D9AEBB5
  1. 62
      guix/build/bournish.scm

62
guix/build/bournish.scm

@ -1,5 +1,6 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2016 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Efraim Flashner <efraim@flashner.co.il>
;;;
;;; This file is part of GNU Guix.
;;;
@ -25,6 +26,7 @@
#:use-module (ice-9 match)
#:use-module (ice-9 ftw)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:export (%bournish-language))
@ -103,6 +105,63 @@ characters."
((@ (guix build utils) dump-port) port (current-output-port))
*unspecified*)))
(define (lines+chars port)
"Return the number of lines and number of chars read from PORT."
(let loop ((lines 0) (chars 0))
(match (read-char port)
((? eof-object?) ;done!
(values lines chars))
(#\newline ;recurse
(loop (1+ lines) (1+ chars)))
(_ ;recurse
(loop lines (1+ chars))))))
(define (file-exists?* file)
"Like 'file-exists?' but emits a warning if FILE is not accessible."
(catch 'system-error
(lambda ()
(stat file))
(lambda args
(let ((errno (system-error-errno args)))
(format (current-error-port) "~a: ~a~%"
file (strerror errno))
#f))))
(define (wc-print file)
(let-values (((lines chars)
(call-with-input-file file lines+chars)))
(format #t "~a ~a ~a~%" lines chars file)))
(define (wc-l-print file)
(let-values (((lines chars)
(call-with-input-file file lines+chars)))
(format #t "~a ~a~%" lines file)))
(define (wc-c-print file)
(let-values (((lines chars)
(call-with-input-file file lines+chars)))
(format #t "~a ~a~%" chars file)))
(define (wc-command-implementation . files)
(for-each wc-print (filter file-exists?* files)))
(define (wc-l-command-implementation . files)
(for-each wc-l-print (filter file-exists?* files)))
(define (wc-c-command-implementation . files)
(for-each wc-c-print (filter file-exists?* files)))
(define (wc-command . args)
"Emit code for the 'wc' command."
(cond ((member "-l" args)
`((@@ (guix build bournish) wc-l-command-implementation)
,@(delete "-l" args)))
((member "-c" args)
`((@@ (guix build bournish) wc-c-command-implementation)
,@(delete "-c" args)))
(else
`((@@ (guix build bournish) wc-command-implementation) ,@args))))
(define (help-command . _)
(display "\
Hello, this is Bournish, a minimal Bourne-like shell in Guile!
@ -129,7 +188,8 @@ commands such as 'ls' and 'cd'; it lacks globbing, pipes---everything.\n"))
("help" ,help-command)
("ls" ,ls-command)
("which" ,which-command)
("cat" ,cat-command)))
("cat" ,cat-command)
("wc" ,wc-command)))
(define (read-bournish port env)
"Read a Bournish expression from PORT, and return the corresponding Scheme

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