Re: How to check the kernel compile options ?

[Andreas Dilger]

On Feb 14, 2002  08:48 -0800, Randy.Dunlap wrote:
> gziphdr=`binoffset $1 0x1f 0x8b 0x08 0x0`
> # increment by 1 since tail offsets are 1-based, not 0-based
> gziphdr=$((gziphdr + 1))
> 
> tail -c +$gziphdr $1 | gunzip > $1.tmp
> strings $1.tmp | grep CONFIG_ > $1.old.config
> rm $1.tmp

How about something like the below (avoids writing a multi-MB temp file):

HDR=`binoffset $1 0x1f 0x8b 0x08 0x0`
dd if=$1 bs=1 skip=$HDR | zcat | strings /dev/stdin | grep CONFIG_

Note also that it is enough to store the config options without the
leading CONFIG_ part, and then use 'grep "[A-Z0-9]*=[ym]$"' to get
the actual config strings.  You can add a final 'sed "s/^/CONFIG_/"'
step to return it to the original format.  So:

dd if=$1 bs=1 skip=$HDR | zcat | strings /dev/stdin | grep "[A-Z0-9]=[ym]$" \
	| sed "s/^//CONFIG_"

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/