CODEWITHSUNDEEP
sed
pogibas
pogibas

Reputation: 28329

sed replace if part of word matches

My text looks like this:

cat
catch
cat_mouse
catty

I want to replace "cat" with "dog".
When I do

sed "s/cat/dog/"

my result is:

dog
catch
cat_mouse
catty

How do I replace with sed if only part of the word matches?

Upvotes: 0

Views: 1547

Answers (4)

Mirage
Mirage

Reputation: 31548

awk solution for this

awk '{gsub("cat","dog",$0); print}' temp.txt

Upvotes: 1

cppcoder
cppcoder

Reputation: 23095

bash-3.00$ cat t
cat
catch
cat_mouse
catty

To replace cat only if it is part of a string 

bash-3.00$ sed 's/cat\([^$]\)/dog\1/' t
cat
dogch
dog_mouse
dogty

To replace all occurrences of cat:

bash-3.00$ sed 's/cat/dog/' t
dog
dogch
dog_mouse
dogty

Upvotes: 2

Gilles Quénot
Gilles Quénot

Reputation: 185025

If you want to replace only cat by dog only if part of the word matches :

$ perl -pe 's/cat(?=.)/dog/' file.txt
cat
dogch
dog_mouse
dogty

I use Positive Look Around, see http://www.perlmonks.org/?node_id=518444

If you really want sed :

sed '/^cat$/!s/cat/dog/' file.txt

Upvotes: 2

Gilles Quénot
Gilles Quénot

Reputation: 185025

There's a mistake : You lack the g modifier

sed 's/cat/dog/g'

g

Apply the replacement to all matches to the regexp, not just the first.

See

Upvotes: 2

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