replace text in UNIX SED

Question

I have text1.txt that contains

<this can be anything, any number of line - no hardcoded>
<this can be anything, any number of line - no hardcoded>
     param1=<this can be any value - no hardcoded>
<this can be anything, any number of line - no hardcoded>
<this can be anything, any number of line - no hardcoded>

And I would like to replace this part this can be any value - no hardcoded with abc

What should be the right SED command? Note that due to environment restriction i don't have the flexibility to use any language such as perl, python, or ruby ~ and can only use Unix command. And no hardcoded except for param1

Thanks a lot in advance!

[This SO question](http://stackoverflow.com/questions/1074450/sed-replace-part-of-a-line) may help. — Ray Toal, Apr 10 '12 at 08:25
@shiplu Could you clarify what constitutes a comment, as per OP's question `text1.txt` is a normal text file, so anything could indicate a comment? — beny23, Apr 10 '12 at 08:37

score 1 · Accepted Answer · answered Apr 10 '12 at 08:28

1

The invocation you want is

sed -e 's/param1=.*/param1=abc/' text1.txt

answered Apr 10 '12 at 08:28

Ray Toal

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This might change all the sample values in comment. No? – Shiplu Mokaddim Apr 10 '12 at 08:33
If you mean that the six-character sequence `param1=` will always have the rest of the characters on its line repleced with `abc` even if it appears in a "comment" then yes. But the OP never said anything about comments. – Ray Toal Apr 10 '12 at 08:36

score 1 · Answer 2 · answered Apr 10 '12 at 09:07

It sounds like you want something like s/<.\+>$/<abc>/:

$ cat test1.txt

<this can be anything, any number of line - no hardcoded>
<this can be anything, any number of line - no hardcoded>
     param1=<this can be any value - no hardcoded>
<this can be anything, any number of line - no hardcoded>
<this can be anything, any number of line - no hardcoded>

$ sed 's/<.\+>$/<abc>/' test1.txt

<abc>
<abc>
     param1=<abc>
<abc>
<abc>

replace text in UNIX SED

2 Answers2