sed - replacing on the right of a pattern and looking for exact word?

how would you get SED to do the following, say you have the following lines in a text file:

user=tigger
some text some text
some text some text
some text some text
user=ted
some text some text
some text some text
some text some text
user=thekingofrockandroll

you want to find any line which has 'user=[the user name]' and replace it with 'user=xxx'

so the string after the 'user=' will always contain a different number of characters but you just want to sed to find any lines with 'user=' and replace the part after 'user=' with 'xxx' no matter what?

and...

if what to replace say 'AM' in a text file with 'JO', i can do:

sed 's/AM/JO/g;s/am/jo/g'

but what if the text file where i'm running this looks like this:

AM
TAME
am
jammy

I only want to replace the following lines with 'JO':

AM
am

so I want to leave 'TAME' and 'jammy' in there - the sed above will give this:

JO
TJOE
jo
JJOMY

I want:

JO
TAME
jo
jammy

how do you achieve that with SED?

Cheers!

sed 's/user=.*/user=xxx/'

and:

sed 's/^am$/jo/i'

hmm, that's not working the 'am' is still present in the file after it has ran? I have:

sed 's/^am$/jo/i' "$f" > "$f".tmp && cp -f "$f".tmp "$f" && rm "$f".tmp

Using OpenSolaris 10 btw, not sure what version of sed i have? will that matter?

---------- Post updated at 04:40 PM ---------- Previous update was at 04:23 PM ----------

the $ was not needed, just the ^

sed 's/^am/jo/i' "$f" > "$f".tmp && cp -f "$f".tmp "$f" && rm "$f".tmp

works now cheers

---------- Post updated at 05:24 PM ---------- Previous update was at 04:40 PM ----------

i see the ^ seems to overide differences between uppercase and lowercase?

^ means start of the line, matching regardles of the characters' case is done by /i modifier.

hmm, what I would like ideally is this (say I'm replacing JO with BO)

my file to run sed on looks like this (as an example):

akdjfdkl sdjfklsjdf jsdfkljsf JO KSJDFKDFJLJOdsjfskldjf dsjfkljsfl <---- first JO on this line should be replaced by sed, second one should not because it forms part of a word
akdjalsd@JO <--- JO should be replaced here by sed
sdfkjdslfjsl@dfdsf_JO <----- and here
JO <---- and here
jo <----- and here

Does it have to be sed?

perl -pe 's/(?<![a-z])jo(?![a-z])/bo/ig' file

Hell no!

is this able to differentiate between upper and lower case?

If you want to differentiate between upper and lower case, then ommit the "i" modifier. I think "i" also modifies behaviour of character range brackets, so A-Z needs to be added.

perl -pe 's/(?<![a-zA-Z])jo(?![a-zA-Z])/bo/g' file

with sed

# sed 's/JO[^ ]*\|jo/bo/' infile
akdjfdkl sdjfklsjdf jsdfkljsf bo KSJDFKDFJLJOdsjfskldjf dsjfkljsfl
akdjalsd@bo
sdfkjdslfjsl@dfdsf_bo
bo
bo

how do you string together multiple find and replaces, whenver I try and do it it only does the first one?

What do you mean? Do you want it to be case sensitive or not? Give us sample input data, that covers all the cases and desired output.

perl -pe 's/(?<![a-z])jo(?![a-z])/bo/g;s(?<![a-z])tom(?![a-z])/bob/g' file

I just need to be able to specify multiple finds and replaces, the above does not work?

cheers!

Because you missed "/" in the second statement:

perl -pe 's/(?<![a-z])jo(?![a-z])/bo/g;s/(?<![a-z])tom(?![a-z])/bob/g' file

yeah noticed that before it's working now! what a dumbass (me) :rolleyes:

sed 's/JO[^ ]*\|jo/bo/' infile

how do you modify this sed line to replace uppercase with uppercase and lowercase with lowercase?