How to replace "," with ", " and saving the previous text?

Question

I want to replace all occurrences in a text with ","

for example

"word1,word2,word3"

became

"word1, word2, word3"

this one is bad

:%s/,/, /g

because

"word1,word2,word3, word4"

became (note the double white space)

"word1, word2, word3,  word4"

This one delete the next letter

:%s/,[a-z]/, /gc
word1,word2...

became

word1, ord2

How to do? Thanks

Friedrich · Answer 1 · 2023-12-11T10:45:40.023

While I'd do it exactly like in romainl's answer, let me point out a few pattern tricks that can make your life easier.

Your almost-solution :%s/,[a-z]/, /gc can be turned into a working solution by ending the match after the comma using the \ze (end match) atom like this

:%s/,\ze[a-z]/, /gc

This will exclude the letter following the comma from being part of the match. This is explained in :help /\ze. (Also see :help /\zs for the start match atom.)

To allow for words starting with capital letters, consider using ,\ze\S or ,\ze\w which will match non-whitespace or word characters, respectively. See :help /\S and :help /\w.

As I initially said, romainl's solution is perfect for this example. For more complex problems, these often come in handy.

score 4 · Accepted Answer · answered Dec 10 '23 at 21:12

sed -i 's/,/, /g; s/,\s\+/, /g'

You can use the exact same logic directly in Vim:

:%s/,/, /g
:%s/,\s\+/, /g

In general, I think doing things in n smaller and more intuitive steps is more efficient than wasting hours figuring out a smart and more elegant one-liner… but this is not such a case.

The following does what you want in a single take:

:%s/,\s*/, /g

The pattern matches:

a single comma, ,,
followed by zero or more whitespace characters, as many as possible, \s*,

witch covers , (because there is zero whitespace after the comma), and any variant of , , , , etc.

See :help /*.

score 2 · Answer 3 · answered Jan 29 '24 at 15:38

2

This can be achieved using captures

:%s/,\(\w\)/, \1/g

Search for a ,, capture a word character, replace with a , followed by that same captured word character \1.

answered Jan 29 '24 at 15:38

Adam

121
1

elbarna · Answer 4 · 2023-12-12T17:12:56.417

0

Actually this workaround works, but using external command

:! sed 's/,/, /g; s/,\s\+/, /g'

edited Dec 12 '23 at 17:12

answered Dec 10 '23 at 20:21

elbarna

179
4

This solution would work in Vim as well... So why not make this a proper Vim answer? – Christian Brabandt Dec 10 '23 at 21:50
1

It would be better to write :[range]!sed <sed script> and let sed filter the input. – D. Ben Knoble Dec 11 '23 at 01:53
1

Wouldn't sed -i need an input file, like a % appended to the line? – Friedrich Dec 12 '23 at 11:30
1

Thanks I have correct it. – elbarna Dec 12 '23 at 17:13

How to replace "," with ", " and saving the previous text?

4 Answers4