Danny Milosavljevic wrote 8 years ago
(address . guix-patches@gnu.org)(name . Danny Milosavljevic)(address . dannym@scratchpost.org)
20170608192652.28420-1-dannym@scratchpost.org
* gnu/build/file-systems.scm (string->iso9660-uuid): New variable. Export it.
---
gnu/build/file-systems.scm | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
Toggle diff (40 lines)
diff --git a/gnu/build/file-systems.scm b/gnu/build/file-systems.scm
index 7737de3d0..1c733f43b 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)