blob: 5b85a0e5810dc092b0b79bbaf8def1853f480100 (
about) (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2021 Andrew Tropin <andrew@trop.in>
;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
;;; Copyright © 2022 Ludovic Courtès <ludo@gnu.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 (gnu home services symlink-manager)
#:use-module (gnu home services)
#:use-module (guix gexp)
#:use-module (guix modules)
#:export (home-symlink-manager-service-type))
;;; Comment:
;;;
;;; symlink-manager cares about xdg configurations and other files: it backs
;;; up files created by user, removes symlinks and directories created by a
;;; previous generation, and creates new directories and symlinks to files
;;; according to the content of directories (created by home-files-service) of
;;; the current home environment generation.
;;;
;;; Code:
(define (update-symlinks-script)
(program-file
"update-symlinks"
(with-imported-modules (source-module-closure
'((guix build utils)
(guix i18n)))
#~(begin
(use-modules (ice-9 ftw)
(ice-9 match)
(srfi srfi-1)
(guix i18n)
(guix build utils))
(define home-directory
(getenv "HOME"))
(define xdg-config-home
(or (getenv "XDG_CONFIG_HOME")
(string-append (getenv "HOME") "/.config")))
(define xdg-data-home
(or (getenv "XDG_DATA_HOME")
(string-append (getenv "HOME") "/.local/share")))
(define backup-directory
(string-append home-directory "/" (number->string (current-time))
"-guix-home-legacy-configs-backup"))
(define (preprocess-file file)
"If file is in XDG-CONFIGURATION-FILES-DIRECTORY use
subdirectory from XDG_CONFIG_HOME to generate a target path."
(cond
((string-prefix? #$xdg-configuration-files-directory file)
(string-append
(substring xdg-config-home
(1+ (string-length home-directory)))
(substring file
(string-length #$xdg-configuration-files-directory))))
((string-prefix? #$xdg-data-files-directory file)
(string-append
(substring xdg-data-home
(1+ (string-length home-directory)))
(substring file
(string-length #$xdg-data-files-directory))))
(else file)))
(define (target-file file)
;; Return the target of FILE, a config file name sans leading dot
;; such as "config/fontconfig/fonts.conf" or "bashrc".
(string-append home-directory "/" (preprocess-file file)))
(define (no-follow-file-exists? file)
"Return #t if file exists, even if it's a dangling symlink."
(->bool (false-if-exception (lstat file))))
(define (symlink-to-store? file)
(catch 'system-error
(lambda ()
(store-file-name? (readlink file)))
(lambda args
(if (= EINVAL (system-error-errno args))
#f
(apply throw args)))))
(define (backup-file file)
(define backup
(string-append backup-directory "/" (preprocess-file file)))
(mkdir-p backup-directory)
(format #t (G_ "Backing up ~a...") (target-file file))
(mkdir-p (dirname backup))
(rename-file (target-file file) backup)
(display (G_ " done\n")))
(define (cleanup-symlinks home-generation)
;; Delete from $HOME files that originate in HOME-GENERATION, the
;; store item containing a home generation.
(define config-file-directory
;; Note: Trailing slash is needed because "files" is a symlink.
(string-append home-generation "/" #$home-files-directory "/"))
(define (strip file)
(string-drop file
(+ 1 (string-length config-file-directory))))
(format #t (G_ "Cleaning up symlinks from previous home at ~a.~%")
home-generation)
(newline)
(file-system-fold
(const #t)
(lambda (file stat _) ;leaf
(let ((file (target-file (strip file))))
(when (no-follow-file-exists? file)
;; DO NOT remove the file if it is no longer a symlink to
;; the store, it will be backed up later during
;; create-symlinks phase.
(if (symlink-to-store? file)
(begin
(format #t (G_ "Removing ~a...") file)
(delete-file file)
(display (G_ " done\n")))
(format
#t
(G_ "Skipping ~a (not a symlink to store)... done\n")
file)))))
(const #t) ;down
(lambda (directory stat _) ;up
(unless (string=? directory config-file-directory)
(let ((directory (target-file (strip directory))))
(catch 'system-error
(lambda ()
(rmdir directory)
(format #t (G_ "Removed ~a.\n") directory))
(lambda args
(let ((errno (system-error-errno args)))
(cond
((= ENOTEMPTY errno)
(format
#t
(G_ "Skipping ~a (not an empty directory)... done\n")
directory))
((= ENOTDIR errno) #t)
(else
(apply throw args)))))))))
(const #t) ;skip
(const #t) ;error
#t ;init
config-file-directory
lstat)
(display (G_ "Cleanup finished.\n\n")))
(define (create-symlinks home-generation)
;; Create in $HOME symlinks for the files in HOME-GENERATION.
(define config-file-directory
;; Note: Trailing slash is needed because "files" is a symlink.
(string-append home-generation "/" #$home-files-directory "/"))
(define (strip file)
(string-drop file
(+ 1 (string-length config-file-directory))))
(define (source-file file)
(readlink (string-append config-file-directory file)))
(file-system-fold
(const #t) ;enter?
(lambda (file stat result) ;leaf
(let ((source (source-file (strip file)))
(target (target-file (strip file))))
(when (no-follow-file-exists? target)
(backup-file (strip file)))
(format #t (G_ "Symlinking ~a -> ~a...")
target source)
(symlink source target)
(display (G_ " done\n"))))
(lambda (directory stat result) ;down
(unless (string=? directory config-file-directory)
(let ((target (target-file (strip directory))))
(when (and (no-follow-file-exists? target)
(not (file-is-directory? target)))
(backup-file (strip directory)))
(catch 'system-error
(lambda ()
(mkdir target))
(lambda args
(let ((errno (system-error-errno args)))
(unless (= EEXIST errno)
(format #t (G_ "failed to create directory ~a: ~s~%")
target (strerror errno))
(apply throw args))))))))
(const #t) ;up
(const #t) ;skip
(const #t) ;error
#t ;init
config-file-directory))
#$%initialize-gettext
(let* ((home (string-append home-directory "/.guix-home"))
(pivot (string-append home ".new"))
(new-home (getenv "GUIX_NEW_HOME"))
(old-home (getenv "GUIX_OLD_HOME")))
(when old-home
(cleanup-symlinks old-home))
(create-symlinks new-home)
(symlink new-home pivot)
(rename-file pivot home)
(display (G_" done\nFinished updating symlinks.\n\n")))))))
(define (update-symlinks-gexp _)
#~(primitive-load #$(update-symlinks-script)))
(define home-symlink-manager-service-type
(service-type (name 'home-symlink-manager)
(extensions
(list
(service-extension
home-activation-service-type
update-symlinks-gexp)))
(default-value #f)
(description "Provide an @code{update-symlinks}
script, which creates symlinks to configuration files and directories
on every activation. If an existing file would be overwritten by a
symlink, backs up that file first.")))
|
