guix-devel/guix/ui.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2013 Mark H Weaver <mhw@netris.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 ui)
#:use-module (guix utils)
#:use-module (guix store)
#:use-module (guix config)
#:use-module (guix packages)
#:use-module (guix derivations)
#:use-module ((guix licenses) #:select (license? license-name))
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (ice-9 match)
#:use-module (ice-9 format)
#:export (_
N_
leave
show-version-and-exit
show-bug-report-information
show-what-to-build
call-with-error-handling
with-error-handling
read/eval-package-expression
location->string
call-with-temporary-output-file
switch-symlinks
config-directory
fill-paragraph
string->recutils
package->recutils
run-guix-command
guix-main))
;;; Commentary:
;;;
;;; User interface facilities for command-line tools.
;;;
;;; Code:
(define %gettext-domain
"guix")
(define _ (cut gettext <> %gettext-domain))
(define N_ (cut ngettext <> <> <> %gettext-domain))
(define (install-locale)
"Install the current locale settings."
(catch 'system-error
(lambda _
(setlocale LC_ALL ""))
(lambda args
(format (current-error-port)
(_ "warning: failed to install locale: ~a~%")
(strerror (system-error-errno args))))))
(define (initialize-guix)
"Perform the usual initialization for stand-alone Guix commands."
(install-locale)
(textdomain "guix")
(setvbuf (current-output-port) _IOLBF)
(setvbuf (current-error-port) _IOLBF))
(define-syntax-rule (leave fmt args ...)
"Format FMT and ARGS to the error port and exit."
(begin
(format (current-error-port) fmt args ...)
(exit 1)))
(define* (show-version-and-exit #:optional (command (car (command-line))))
"Display version information for COMMAND and `(exit 0)'."
(simple-format #t "~a (~a) ~a~%"
command %guix-package-name %guix-version)
(exit 0))
(define (show-bug-report-information)
(format #t (_ "
Report bugs to: ~a.") %guix-bug-report-address)
(format #t (_ "
~a home page: <~a>") %guix-package-name %guix-home-page-url)
(display (_ "
General help using GNU software: <http://www.gnu.org/gethelp/>"))
(newline))
(define (call-with-error-handling thunk)
"Call THUNK within a user-friendly error handler."
(guard (c ((package-input-error? c)
(let* ((package (package-error-package c))
(input (package-error-invalid-input c))
(location (package-location package))
(file (location-file location))
(line (location-line location))
(column (location-column location)))
(leave (_ "~a:~a:~a: error: package `~a' has an invalid input: ~s~%")
file line column
(package-full-name package) input)))
((nix-protocol-error? c)
;; FIXME: Server-provided error messages aren't i18n'd.
(leave (_ "error: build failed: ~a~%")
(nix-protocol-error-message c))))
(thunk)))
(define (read/eval-package-expression str)
"Read and evaluate STR and return the package it refers to, or exit an
error."
(let ((exp (catch #t
(lambda ()
(call-with-input-string str read))
(lambda args
(leave (_ "failed to read expression ~s: ~s~%")
str args)))))
(let ((p (catch #t
(lambda ()
(eval exp the-scm-module))
(lambda args
(leave (_ "failed to evaluate expression `~a': ~s~%")
exp args)))))
(if (package? p)
p
(leave (_ "expression `~s' does not evaluate to a package~%")
exp)))))
(define* (show-what-to-build store drv #:optional dry-run?)
"Show what will or would (depending on DRY-RUN?) be built in realizing the
derivations listed in DRV. Return #t if there's something to build, #f
otherwise."
(let* ((req (append-map (lambda (drv-path)
(let ((d (call-with-input-file drv-path
read-derivation)))
(derivation-prerequisites-to-build
store d)))
drv))
(req* (delete-duplicates
(append (remove (compose (cute valid-path? store <>)
derivation-path->output-path)
drv)
(map derivation-input-path req)))))
(if dry-run?
(format (current-error-port)
(N_ "~:[the following derivation would be built:~%~{ ~a~%~}~;~]"
"~:[the following derivations would be built:~%~{ ~a~%~}~;~]"
(length req*))
(null? req*) req*)
(format (current-error-port)
(N_ "~:[the following derivation will be built:~%~{ ~a~%~}~;~]"
"~:[the following derivations will be built:~%~{ ~a~%~}~;~]"
(length req*))
(null? req*) req*))
(pair? req*)))
(define-syntax with-error-handling
(syntax-rules ()
"Run BODY within a user-friendly error condition handler."
((_ body ...)
(call-with-error-handling
(lambda ()
body ...)))))
(define (location->string loc)
"Return a human-friendly, GNU-standard representation of LOC."
(match loc
(#f (_ "<unknown location>"))
(($ <location> file line column)
(format #f "~a:~a:~a" file line column))))
(define (call-with-temporary-output-file proc)
"Call PROC with a name of a temporary file and open output port to that
file; close the file and delete it when leaving the dynamic extent of this
call."
(let* ((template (string-copy "guix-file.XXXXXX"))
(out (mkstemp! template)))
(dynamic-wind
(lambda ()
#t)
(lambda ()
(proc template out))
(lambda ()
(false-if-exception (close out))
(false-if-exception (delete-file template))))))
(define (switch-symlinks link target)
"Atomically switch LINK, a symbolic link, to point to TARGET. Works
both when LINK already exists and when it does not."
(let ((pivot (string-append link ".new")))
(symlink target pivot)
(rename-file pivot link)))
(define (config-directory)
"Return the name of the configuration directory, after making sure that it
exists. Honor the XDG specs,
<http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html>."
(let ((dir (and=> (or (getenv "XDG_CONFIG_HOME")
(and=> (getenv "HOME")
(cut string-append <> "/.config")))
(cut string-append <> "/guix"))))
(catch 'system-error
(lambda ()
(mkdir dir)
dir)
(lambda args
(match (system-error-errno args)
((or EEXIST 0)
dir)
(err
(leave (_ "failed to create configuration directory `~a': ~a~%")
dir (strerror err))))))))
(define* (fill-paragraph str width #:optional (column 0))
"Fill STR such that each line contains at most WIDTH characters, assuming
that the first character is at COLUMN.
When STR contains a single line break surrounded by other characters, it is
converted to a space; sequences of more than one line break are preserved."
(define (maybe-break chr result)
(match result
((column newlines chars)
(case chr
((#\newline)
`(,column ,(+ 1 newlines) ,chars))
(else
(let ((chars (case newlines
((0) chars)
((1) (cons #\space chars))
(else
(append (make-list newlines #\newline) chars))))
(column (case newlines
((0) column)
((1) (+ 1 column))
(else 0))))
(let ((chars (cons chr chars))
(column (+ 1 column)))
(if (> column width)
(let*-values (((before after)
(break (cut eqv? #\space <>) chars))
((len)
(length before)))
(if (<= len width)
`(,len
0
,(if (null? after)
before
(append before (cons #\newline (cdr after)))))
`(,column 0 ,chars))) ; unbreakable
`(,column 0 ,chars)))))))))
(match (string-fold maybe-break
`(,column 0 ())
str)
((_ _ chars)
(list->string (reverse chars)))))
(define (string->recutils str)
"Return a version of STR where newlines have been replaced by newlines
followed by \"+ \", which makes for a valid multi-line field value in the
`recutils' syntax."
(list->string
(string-fold-right (lambda (chr result)
(if (eqv? chr #\newline)
(cons* chr #\+ #\space result)
(cons chr result)))
'()
str)))
(define* (package->recutils p port
#:optional (width (or (and=> (getenv "WIDTH")
string->number)
80)))
"Write to PORT a `recutils' record of package P, arranging to fit within
WIDTH columns."
(define (description->recutils str)
(let ((str (_ str)))
(string->recutils
(fill-paragraph str width
(string-length "description: ")))))
;; Note: Don't i18n field names so that people can post-process it.
(format port "name: ~a~%" (package-name p))
(format port "version: ~a~%" (package-version p))
(format port "location: ~a~%"
(or (and=> (package-location p) location->string)
(_ "unknown")))
(format port "home-page: ~a~%" (package-home-page p))
(format port "license: ~a~%"
(match (package-license p)
(((? license? licenses) ...)
(string-join (map license-name licenses)
", "))
((? license? license)
(license-name license))
(x
(_ "unknown"))))
(format port "synopsis: ~a~%"
(string-map (match-lambda
(#\newline #\space)
(chr chr))
(or (and=> (package-synopsis p) _)
"")))
(format port "description: ~a~%"
(and=> (package-description p) description->recutils))
(newline port))
(define (show-guix-usage)
;; TODO: Dynamically generate a summary of available commands.
(format (current-error-port)
(_ "Usage: guix COMMAND ARGS...~%")))
(define (run-guix-command command . args)
;; TODO: Gracefully report errors
(let* ((module (resolve-interface `(guix scripts ,command)))
(command-main (module-ref module
(symbol-append 'guix- command))))
(apply command-main args)))
(define (guix-main arg0 . args)
(initialize-guix)
(let ()
(define (option? str) (string-prefix? "-" str))
(match args
(() (show-guix-usage) (exit 1))
(("--help") (show-guix-usage))
(("--version") (show-version-and-exit "guix"))
(((? option? arg1) args ...) (show-guix-usage) (exit 1))
((command args ...)
(apply run-guix-command
(string->symbol command)
args)))))
;;; ui.scm ends here