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authorDanny Milosavljevic <dannym@scratchpost.org>2017-06-08 21:24:36 +0200
committerDanny Milosavljevic <dannym@scratchpost.org>2017-06-09 12:30:56 +0200
commitbb7cf4f5335370c4a29adc236816851076c0fe61 (patch)
tree981965b52a1fdab9b471c3c1a048b153842846c0
parent19c90e5f697bbf1be5ea3a7b4f5fe712d77070a1 (diff)
downloadguix-bb7cf4f5335370c4a29adc236816851076c0fe61.tar
guix-bb7cf4f5335370c4a29adc236816851076c0fe61.tar.gz
file-systems: Provide string->iso9660-uuid.
* gnu/build/file-systems.scm (string->iso9660-uuid): New variable. Export it. Co-authored-by: Ludovic Courtès <ludo@gnu.org>
-rw-r--r--gnu/build/file-systems.scm22
1 files changed, 22 insertions, 0 deletions
diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm
index 7737de3d03..1c733f43b4 100644
--- a/gnu/build/file-systems.scm
+++ b/gnu/build/file-systems.scm
@@ -43,6 +43,7 @@
uuid->string
string->uuid
+ string->iso9660-uuid
bind-mount
@@ -235,6 +236,27 @@ Trailing spaces are trimmed."
;; <http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf>.
+(define %iso9660-uuid-rx
+ ;; Y m d H M S ss
+ (make-regexp "^([[:digit:]]{4})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})-([[:digit:]]{2})$"))
+
+(define (string->iso9660-uuid str)
+ "Parse STR as a ISO9660 UUID (which is really a timestamp - see /dev/disk/by-uuid).
+Return its contents as a 16-byte bytevector. Return #f if STR is not a valid
+ISO9660 UUID representation."
+ (and=> (regexp-exec %iso9660-uuid-rx str)
+ (lambda (match)
+ (letrec-syntax ((match-numerals
+ (syntax-rules ()
+ ((_ index (name rest ...) body)
+ (let ((name (match:substring match index)))
+ (match-numerals (+ 1 index) (rest ...) body)))
+ ((_ index () body)
+ body))))
+ (match-numerals 1 (year month day hour minute second hundredths)
+ (string->utf8 (string-append year month day
+ hour minute second hundredths)))))))
+
(define (iso9660-superblock? sblock)
"Return #t when SBLOCK is an iso9660 volume descriptor."
(bytevector=? (sub-bytevector sblock 1 6)