[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

GRUB 2.00 conditional structures (statements) syntax

From: sashab
Subject: GRUB 2.00 conditional structures (statements) syntax
Date: Tue, 15 Oct 2013 12:20:16 +0200
User-agent: freenetMail

Dear all, 

unfortunately i was not able to find any documentation on usage of conditional 
statements in grub configuration files.

According to the “GNU GRUB Manual 2.00~rc1” found on the 
words 'if', 'fi', 'case', 'esac', 'in' and so on are reserved.
Furthermore the scripting language is referred to as “Shell-like”.

Simple “if [ $condition ]; then #dosomething; fi”-statements are not 
But I wasn't able to find a functional syntax for the case-statements.

To make it short: I would like to compare strings in the grub cli.

Is there any more or less exhaustive documentation about the syntax or am I 
just too dumb to use google?

The most recent version I used to test stuff was the 2.00 that comes shipped 
with arch linux.

What I'm trying to do:

I want to implement a grub configuration file that automatically generates menu 

For en example: 
The following procedure should create entries for (small) files to be loaded 
with memdisk ( from the syslinux project).
/boot/memsik is our kernel.
Our file is the initrd.
We assume that the files can be PREFIX_*.* or just *.* or README*.
(e.g. README || FLOPPY_dellbiosupdate.img || freedos.img)
The README*-files should not be processed.
For files with a prefix, the prefix should be appended as a kernel-parameter.
For files without there are no parameters to append.

I supposed that this would be “shell-like” (file=$img):

[code source=”/boot/grub/grub.cfg”]
. ..
insmod ext2
insmod regexp
. ..
set pathtoimages=”/boot/images”
. ..
for img in ${pathtoimages}/*; do
  set appendstr=””
  case ${img} in
    */README*)  continue  ;;
    */FLOPPY_*) set appendstr=${appendstr} floppy ;;
  menuentry “MEMDISK - $img” “$img” “$appendstr” {
    linux16 /boot/memdisk ${3}
    initrd16 ${2}
. ..

I also tried to use other quoting notations with no success.
Futhermore I also tried “if [[ ${img} == */FLOPPY_* ]]; ...”.

Thank you very much in advance!

With kind regards, 
    Sasha B.

P.S.: Sorry if something's misspelled, English isn't my native tongue.

Alle Postfächer an einem Ort. Jetzt wechseln und E-Mail-Adresse mitnehmen!

reply via email to

[Prev in Thread] Current Thread [Next in Thread]