How to regex in Vim

Question

I want to add some text before each return For example we have :

void* foo (){
   if (something){ 
   return A;
   }
do_something;
// That return word may be ignored, because it's comment
do_something;
returns(); //It may ignored to
return ;
}

I need :

void* foo (){
   if (something){
   END;
   return A;
   }
do_something;
// That return word may be ignored, becouse it's comment
do_something;
returns(); //It may ignored to
END;
return ;
}

I can't build regex for search request. It may looks like "

return"< some text here started with space symbol, or nothing >;<endline>

How I can make it in VIM?

What do you mean by "I can't build regex for search request." What did you try that didn't work? — FDinoff
– FDinoff, Commented Jul 18, 2013 at 18:31
You can substitute patterns in vim by first getting to the command mode. That is done by typing ':'. Then you can substitute patterns in the whole file by '%s///'. If you had a file with the text 'test' then '%s/test/two\rlines/' will replace the word 'test' with 'two', then a newline, then 'line'. For you '%s/returns();/returns();\rEND;/' may be what you are going for, but I'm not 100% on what you are intending. — conornicol
– conornicol, Commented Jul 18, 2013 at 18:59
A tutorial on and reference for Vim regular expressions: vimregex.com — Rory O'Kane
– Rory O'Kane, Commented Jul 18, 2013 at 22:35
Thanks for tutorial. I don't understand how can i missed it when googled. About search requests..... Before it I made macroses with simple logic: /return^MOEND;^[<80>kd (search "return" and add "END;" before it), and run it 1000 times (with set nowrapscan). Main problem was that /return search word "return" in coments. The main question was "What regex (for "return ;" "return var;" but not "// return") i need write after / to search what i whant? " — Stepan Loginov
– Stepan Loginov, Commented Jul 21, 2013 at 12:45

cforbish · Accepted Answer · 2013-07-18 21:37:55Z

7

Using hold registers is an easy way to do this:

%s/^\(\s*\)\(return\>.*\)/\1END;\r\1\2/g

The meanings:

%s - global substitute
/  - field separator
^  - start of line
\( - start hold pattern
\s - match whitespace
*  - 0 or more times
\) - end hold pattern
\> - end of word boundary (prevent returns matching return)
.  - match any character
\1 - recall hold pattern number 1
\2 - recall hold pattern number 2
\r - <CR>
g  - Replace all occurrences in the line

edited Jul 18, 2013 at 21:37

answered Jul 18, 2013 at 21:32

cforbish

8,8893 gold badges32 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Tassos · Accepted Answer · 2013-07-19 12:41:39Z

2

You may use the global command as follows:

:g/^\s*return\>/normal OEND;

It searches for lines having any number of whitespace and the word return, executes the command O and adds the "END;"

Bonus feature the END; is 'auto indented'.

edited Jul 19, 2013 at 12:41

answered Jul 19, 2013 at 9:55

Tassos

3,31830 silver badges31 bronze badges

1 Comment

Stepan Loginov Over a year ago

Thanks. Now I know about multiple repeats. I take macros, set nowrap scan and repeat macros about 1000 times before that day. But now i'll do same work easier. Thank you.

evnu · Accepted Answer · 2013-07-18 19:20:04Z

0

Use a substitution:

:%s/\(return\)/END;\r\1/g

The substitution searches for occurrences of return, remembers such occurrences and places END; followed by a newline in front of those occurrences. You may want to read up on regular expressions in vim's substitution. Note that \(\) groups characters such that a group can be referenced in the substitution again.

Edit

Lets make that example more specific (I hope I hit your corner cases):

:%s/\(return\(\((\|\s\)[^;]\)*;\)/END\r\1/g

The regular expression matches every occurrence of return which is followed by whitespace or opening parenthesis and subsequent characters until ; is encountered. Such an occurrence is substituted with itself and a prepended END.

edited Jul 18, 2013 at 19:20

answered Jul 18, 2013 at 18:55

evnu

6,7402 gold badges29 silver badges39 bronze badges

1 Comment

Manny D Over a year ago

I think it's a little more complicated than that. The poster has some cases in the code that he wants ignored and your regex will hit all of them. return appears multiple times like in returns(); and in the comment.

Manny D · Accepted Answer · 2013-07-18 20:01:04Z

0

:%s/.*\(\/\/.*\)\@<!\<return\>.*/END\r&/g

This basically says "find any line with a return statement that's not in a comment and replace it with END, newline, then the original line". The key to this is the lookbehind (\(\/\/.*\)\@<!) which essentially ignores any instances of return in a comment. The \<return\> makes sure you only search for return and not something like returns.

I tested using:

//return here
return; // return as mentioned
if (cornerCase) { return 1; }
returns();
return 0;

Which became this after the replace:

//return here
END
return; // return as mentioned
END
if (cornerCase) { return 1; }
returns();
END
return 0;

answered Jul 18, 2013 at 20:01

Manny D

20.9k2 gold badges31 silver badges31 bronze badges

Comments

Peter Rincker · Accepted Answer · 2013-07-18 22:30:57Z

0

:%s/^\(\s*\)\<return\>/\1END;\r&/

Use & to return what was matched. Similar to \0 in Perl.

answered Jul 18, 2013 at 22:30

Peter Rincker

45.6k9 gold badges79 silver badges113 bronze badges

Collectives™ on Stack Overflow

How to regex in Vim

5 Answers 5

Comments

1 Comment

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

1 Comment

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related