01/01: linux-boot: Add find-long-options.

[Danny Milosavljevic]

dannym pushed a commit to branch master
in repository guix.

commit 015d0a8418d867c13ae83acb44dc1157df2fedae
Author: Danny Milosavljevic <address@hidden>
Date:   Wed Jan 31 13:28:21 2018 +0100

    linux-boot: Add find-long-options.
    
    * gnu/build/linux/boot.scm (find-long-options): New variable.
---
 gnu/build/linux-boot.scm | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gnu/build/linux-boot.scm b/gnu/build/linux-boot.scm
index 0ab8391..c9de4f4b 100644
--- a/gnu/build/linux-boot.scm
+++ b/gnu/build/linux-boot.scm
@@ -37,6 +37,7 @@
   #:export (mount-essential-file-systems
             linux-command-line
             find-long-option
+            find-long-options
             make-essential-device-nodes
             make-static-device-nodes
             configure-qemu-networking
@@ -99,6 +100,16 @@ Return the value associated with OPTION, or #f on failure."
            (lambda (arg)
              (substring arg (+ 1 (string-index arg #\=)))))))
 
+(define (find-long-options option arguments)
+  "Find OPTIONs among ARGUMENTS, where OPTION is something like \"console\".
+Return the values associated with OPTIONs as a list, or the empty list if
+OPTION doesn't appear in ARGUMENTS."
+  (let ((opt (string-append option "=")))
+    (filter-map (lambda (arg)
+                  (and (string-prefix? opt arg)
+                       (substring arg (+ 1 (string-index arg #\=)))))
+                arguments)))
+
 (define* (make-disk-device-nodes base major #:optional (minor 0))
   "Make the block device nodes around BASE (something like \"/root/dev/sda\")
 with the given MAJOR number, starting with MINOR."