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"sed" substitution

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# 1  
Old 12-12-2011
"sed" substitution
Hi guys,
I have a file which contains multiple lines as folllows:
Quote:
if grep $host bbcpu.lst
I need to substitute all the above mentioned instances by the following:
Quote:
if grep "^$host " bbcpu.lst
I have tried several "sed" combinations to achieve this, but they all failed.

May be somebody can recommend the command to do it?
It does not necessary be with "sed", thanks a lot
# 2  
Old 12-12-2011
Code:
[user@host2: /tmp] cat 1.txt
if grep $host bbcpu.lst
[user@host2: /tmp] sed 's/\$host/"^$host "/g' 1.txt
if grep "^$host " bbcpu.lst

EDIT:
Although that's probably a bit too general! More specific:
Code:
sed 's/if grep \$host bbcpu.lst/if grep "^$host " bbcpu.lst/g' 1.txt

# 3  
Old 12-12-2011
Thanks a lot, but the above pattern will also do the substitutions for the lines which are correct. For example after running the command I get the following:
Quote:
if grep "^"^$host " " bbcpu.lst
which is wrong Smilie

---------- Post updated at 11:52 AM ---------- Previous update was at 11:44 AM ----------

Carlo, thanks a lot. The second pattern worked Smilie
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