CODEWITHSUNDEEP
bash
Leo Chan
Leo Chan

Reputation: 4427

Are there any ways to obtain the line number of the matched pattern line?

For example , A text file has:

dfsdfsd
f
dsf
dsf
dsf
dsf
sdafadfdasfdsfd
sf
sdfasdfdasfdsfsdf
sd
fsdfdsaf

Then , i would like to find a way to obtain the line number of sf and insert a paragraph before sf

Are there any ways to doing it in bash programming ???thanks

Upvotes: 3

Views: 1473

Answers (3)

glenn jackman
glenn jackman

Reputation: 247182

sed has more commands than just s///. To insert text before each matching line:

sed '/pattern/ i \
text to be \
inserted goes \
here'

Upvotes: 1

carlpett
carlpett

Reputation: 12613

If you want to find out the line number, you could use grep -n.

If you just want to insert a line on the preceding line, you could use sed like this: 

sed "s/sd/paragraph\nsd/" file

This will insert the text "paragraph" above the line with "sd".

To only do this for the first match:

sed "0,/sd/ { s/sd/paragraph\nsd/ }" file

Here, we only match lines until the first matching "sd", so any later sd's will not match.

Upvotes: 1

Flynn1179
Flynn1179

Reputation: 12075

Possibly a regex replace, replacing \nsf\n with \n\nsf\n, or something similar depending on your specific requirements. Doesn't get you the actual line number, but if all you want to do is insert a paragraph, that may not be necessary.

Upvotes: 0

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