Links: Vim
Search and replace
The search and replace function in Vim is done through a command on Command Mode, that allows us to have a lot of
control over it.
The way you’re probably going to use the most is this: :%s/bad/good/g this would change all words “bad” to “good” in the file.
The command divides in the next way:
:[range] s[ubstitute]/pattern/string/[flags] [count]
where the parameters between brackets are optional
range
On our first example the range was ”%”, that defines the whole file, but we can also omit it to execute the same thing
on just one line. in a similar way you could do :1,10s/bad/good/g to execute the command in lines one to ten.
while defining ranges you can use the next table and it’s combinations:
| range | description |
|---|---|
| . | current line |
| 1 | first line |
| $ | last line |
| % | all lines |
| .+1 | line after current |
| 1,10 | range between 1 and 10 |
flags
Flags can be combined as well, and aren’t required.
Using the previous example you can add a confirmation with the flag “c” :$s/bad/good/gc
| flag | description |
|---|---|
| g | replace all |
| c | ask for confirmation |
| i | ignore case for the pattern |
| I | don’t ignore case for the pattern |
Regular expressions
You can use regular expressions inside the commands, this gives us a lot of flexibility.
Notice that to use regex you need to add ”\” before the expressions so they aren’t counted as regular text
Here are some examples:
:$s/\(bad\|good\)/great/g This would replace any instance of “bad” or “good” with “great”
:$s/\<good\>/bad/g This would replace only good as a whole word
The global command
The global command can also be quite useful, it works in a similar way to substitute.
The syntax is: :[range]g/pattern/command
Where pattern is what we are looking to match in the file and command is what we want to execute for each line matching the pattern.
As an example we can run :g/error/d to execute the command d delete on every line that contains the word “error”.
We could also run :g!/error/d to invert the search, this time deleting every line that doesn’t contain “error”.
You can also execute a substitute command inside a global command like in :g/bad/s/good/great/g where
it runs the command s/good/great/g for every line containing the word “bad”
Note that although in this examples d is both a normal mode command and a command mode command, you can only execute command mode commands with the global command.
That said, you can use the normal prefix to execute a normal mode command like in this example: :g/something/normal @a where we execute the macro in register “a” for every line containing “something”.