[SOLVED] sed command question

whjeon · 03-14-2018, 11:12 PM

Dear mentors

I have one question.
What does '@' mean, in command below
sed -e 's@/lib/ ~blahblah

Thanks for your help!

BudiKusasi · 03-15-2018, 12:09 AM

you just looked at a typo typed by someone, nothing such in sed

whjeon · 03-15-2018, 12:37 AM

Quote:

Originally Posted by BudiKusasi

you just looked at a typo typed by someone, nothing such in sed

Thanks for your reply, but that's no way! That command was from LFS book.
I'll attach exact command this time.

sed -e 's@/lib$64$\?$32$\?/ld@/tools&@g' \
-e 's@/usr@/tools@g' $file.orig > $file
(If it shows 'won currency', that's because I live in Korea. that's all convertible with 'backslash'

JJJCR · 03-15-2018, 12:47 AM

You must look into $file.orig what's inside there.

Here's a link from G search: https://stackoverflow.com/questions/...omplex-replace

BudiKusasi · 03-15-2018, 12:53 AM

This is Linux stable-tested forum not LFS which could be different in the local character interpretations, find a place for proper LFS forum

whjeon · 03-15-2018, 12:54 AM

Quote:

Originally Posted by BudiKusasi

This is Linux stable-tested forum not LFS which could be different in the local character intepretation, find a place for proper LFS forum

OK! Thanks for your help. I thought it would be a 'sed command's feature or REGEX thing.
Thanks again

BudiKusasi · 03-15-2018, 01:07 AM

@JJJCR.. thanks..
now just remember that follows the command must be a separator
@whjeon.. sorry for incorrect reply
s is a command and whatever immediately follows it is a regex-replcement separator character.

so regex is

Code:

/lib\(64\)\?\(32\)\?/ld

and replacement

Code:

/tools&

and option

Code:

MadeInGermany · 03-15-2018, 02:02 AM

Yes, the character following the s command becomes the separator.
Usually one takes the / but here it conflicts with the / in the regexp and substitution strings.
I think that # would look nicer than @

Code:

sed -e 's#/lib\(64\)\?\(32\)\?/ld#/tools&#g' \
 -e 's#/usr#/tools#g' $file.orig > $file

The & in the substitution string means "all that matched".
I think they mean lib optionally followed by either 64 or 32, so the following is more correct

Code:

sed -r -e 's#/lib(64|32)?/ld#/tools&#g' \
 -e 's#/usr#/tools#g' $file.orig > $file

whjeon · 03-15-2018, 02:06 AM

Quote:

Originally Posted by MadeInGermany

Yes, the character following the s command becomes the separator.
Usually one takes the / but here it conflicts with the / in the regexp and substitution strings.
I think that # would look nicer than @

Thanks! Now I understand what it meant.