Substitute in vim, with special characters - vim

I am trying to use substitute command in vim to enclose all occurences of a particular pattern
\cite{author1}
\cite{author2}
with
(\cite{author1})
(\cite{author2})
Based on other answers in stack exchangeI used the following vim command
%s/\\cite{(\w\+)}/(\\cite{\1})/g
But, no luck. It says "no matches found". I put two back slashes, one of which is supposed to be the escape character. Kindly help.
I know I could use some other editor and finish the job, but I want to know my mistake. Thank you.

please escape ()
%s/\\cite{\(\w\+\)}/(\\cite{\1})/g

You do not need a capture group to get the entire match. You can use \0 or & for the whole match in the replacement portion of your substitution.
:%s/\\cite{\w\+}/(&)/g
If you do want to use a capture group, then you need to escape the capture group/parenthesis.
:%s/\(foo\)/(\1)/g
For more help see:
:h :s%
:h /magic

As mentioned, normally you need escape the parentheses.
You can use very magic mode (\v) to make the regex simpler; removing the need to escape lots of the regex parts, including the parentheses for capturing:
%s/\v(\\cite\{\w+\})/(\1)/g

Knowing what every sign in a regular expression does in vim is sometimes very
difficult, especially for all the modes and configuration variables that this
depends on. For that reason, it is very important to have visual feedback about
what text are we really matching in any moment while crafting regular
expressions.
If you work with neovim, there is a special option called inccommand that you
can enable to live preview the matches and substitution. That way you can figure
out you errors more quickly. This feature is very likely to be included also in
vim in the future, but independently of that, you can also use simple vim to
give you visual feedback if you enable the option incsearch.
With incsearch set, you can watch the matches of / and ? while you write them
just to be sure that the pattern is correct. Later you can exploit a nice
feature from the substitution: if you leave the first section empty, the last
search will be used.
So you could first make the search:
/\\cite{\w\+}/(&)/g
In the meantime, vim will be showing you the matched text visually. Once you
are sure that the pattern is correct press enter, and finally type:
:%s//(\1)<Enter>
Also, in case you want something more powerful than this simple hack, you can go
for my plugin Extend.vim, that can
do that and much more with great visual feedback.

Related

is there a way to see the replaced selection after search and replace in vim

When replacing a regex in vim using search and replace in vim, is there a way to see the result before moving onto the next replace.
The interactive option shows the string matching the regex before replace, but with a complex regex it might or might not work as expected so.
If theres a plugin or hack or default option to achieve this i would really like to know.
The traces.vim plugin provides range, pattern and substitute preview for Vim.
Neovim has a native method to do substitutions previews. I believe it is the 'inccommand' option.

Is there a one-liner to tell vim/ctags autocompletion to search from the middle of a word?

In vim (in Insert mode, after running exuberant ctags), I am using ctrl-x followed by ctrl-] to bring up a dropdown of various possible words/tokens. It's a great feature.
The problem is that by default, this list starts with a bunch of numeric options and automatically inserts the first numeric option, and if I backspace to get rid of the numbers and start typing a part of a word fresh -- with the idea of searching from the middle of the word -- the autocompletion behavior exits entirely.
I know I could type the first letter of the word that I want, then go from there. But that assumes that I know the first letter of the word, which is not necessarily a given.
For example, if I'm working on a pair-programming project with a friend during a long weekend, I might not remember at any given moment whether he called his method promoteRecordStatus(), updateRecordStatus() or boostRecordStatus(). In this example, I would like to type RecordStatus and get the relevant result, which does not seem to be possible at a glance with the current behavior.
So with that scenario in mind: Is there a simple, vim-native way to tell the editor to start its autocompletion without any assumptions, then search all available tokens for my typed string in all parts of each token?
I will of course consider plugin suggestions helpful, but I would prefer a short, vim-native answer that doesn't require any plugins if possible. Ideally, the configuration could be set using just a line or two.
The built-in completions all require a match at the starting position. In some cases, you could drop separator characters from the 'iskeyword' option (e.g. in Vimscript, drop # to be able to complete individual components from foo#bar#BazFunction()), but this won't work for camelCaseWords at all.
Custom :help complete-functions can implement any completion search, though. To be based on the tags database, it would have to use taglist() as a source, and filter according to the completion base entered before triggering the completion. If you do not anchor this pattern match at the beginning, you have your desired completion.

Is there a way to elegantly comment specific lines in vim search history, similar to " in command-line history?

I am using vim to edit structured text files.
Sometimes I use search-and-replace feature, and sometimes I am better off with search, followed with a macro, in which case I have several macros at hand, and the choice of one depends upon the particular search result.
In both cases, though I have to spend some effort to arrive at an acceptable regex to satisfy my editing needs. As the regexs are often very long and sophisticated, I end up with both command-line history and search history full of my trial-and-error by-products. The correct regex is not always the last one in a series of attempts, so if I want to reuse the hard-earned regex in a similar editing situation, I have to dig through the pile again.
In search-and-replace scenario I have quickly fixed this with comments that I now put in place at the end of a would-be reusable search-and-replace command string, for example:
:%s/very_long_and_sophisticated_regex/another_long_and_sophisticated_regex/gc "comments on what this search and replace command does and how it might be reused
This way I can easily ignore the piles of stuff in my command line history and quickly find relevant re-use candidates, they are shown in different color. The commands are reusable right away, comments are ignored.
Not so with the search history, though.
Having rtfmed and searched the web, I have not found anything similar. At the moment I put quasi-comments using XXX at the end of reusable search strings, for example:
/search_string_containing_very_long_and_sophisticated_regex XXX comments on what it finds and how it might be re-used
This way I can at least find the right string for re-use, but I have to first delete 'XXX' and the comments.
I wonder if there is a more elegant way of commenting the search strings in search history, similar to command-line history.
You used the word "elegant" in your title, and that I don't have on offer. If instead you can also accept a quirky workaround that relies on Vim internals, here's one.
To restate your problem, it is possible to add comments after Ex :commands,
:AComplicatedExCommand -42 -quux " this fizzes the brobble
:HardToRememberCommand test.txt " use this to brew the framble
but the same is not possible for complicated search /queries (or ?queries).
I've just discovered that you can trick Vim by terminating your search query with a literal null byte:
/[Complicated]*regexp/^# this regexp finds all scrobbles
/another\+Rege\x*p/^# use this to search foo bars
The ^# here is a literal NUL. You can enter it by pressing CtrlV and then 000.
Vim will ignore everything after the null byte, but it'll still show the whole line in the search history, including the "comment".
You can add a regexp branch that never matches, e.g. /\%$indicator\|search string
\%$ is a special Vim atom matching the end of the file. Since that will never match when followed by the indicator text, the first branch (up to \|) will never match and therefore can represent your indicator.
I've created the TaggedSearchPattern plugin to make adding the tag and recalling it even easier.

vim how to search for URL

How would you search for the following string in vim?
http://my.url.com/a/b/c
I've tried (a la Very No Magic)
:/\Vhttp://my.url.com/a/b/c
But it gives me:
E492 not an editor command: /\Vhttp://my.url.com/a/b/c
You would think there'd be a simple way to search a string literally... I'm not too interested in slash escaping every slash, or writing a complicated search, because I have to rapidly search different URLs in a text file.
I'm not sure why you get not an editor command since I don't. The simplest way to search without having to escape slashes is to use ? instead, e.g.
:?http://my.url.com/a/b/c
" or since the : is not necessary
?http://my.url.com/a/b/c
This does search in the other direction, so just keep that in mind
another way to search forward (from the position of your cursor) without escaping is use :s command.
you could do:
:%s#http://my.url.com/a/b/c##n
then press n to navigate matched text forward, N backwards
If you want to know how many matches in the buffer, use gn instead of n
note that, I said "without escaping", I was talking about the slash, if you want to do search precisely, you have to escape the period. .. since in regex, . means any char.
Can also set the search register directly.
:let #/='\Vhttp://my.url.com/a/b/c'
Then you can use n and N like normal.
Use MacVim (or GVim). Open the non-regex GUI search using ⌘f (or ctrlf on Windows). This is the recommended way to do a non-regex search in Vim. GUI Vim has many improvements over terminal vim like this one and I would highly suggest using it full time if you aren't already.
Searching in vim is just /, not :/. You can search for that string escaping only the slashes: /http:\/\/my.url.com\/a\/b\/c

Get the last search or search&replace string back in vim?

How can I bring back the last string I used for a search or a search&replace?
For example, assume that I enter :%s/some_text/some_other_text/gc and vim gives me the E486: Patterns not found: some_text error message back. I then realize that I actually meant to write some_magic_text instead of some_text. At that point, how can I get back my original string in the bottom command row (or whatever it is called) so I can change it and do a second search? Is there a nifty little command for that?
In this brief example it looks unnecessary, but when the text you are looking to replace is mighty long and you just typed one letter wrong, it is fantastically annoying to have to retype everything.
And I am using MacVim if that makes any difference.
From the normal mode, hit q/ to navigate through your search history!
Check out this vimvcast which explains what you want.
More generally, you can recall any command you have previously typed by entering the first few characters, and then use arrow multiple times to navigate in history.
In your case, you could type:
:%s<Up>
See :help history
This answer might be good an improvement to what you are after, after all.
Use search with highlighting, to interactively check if the regex you are crafting is definitely working, and then use it in a search-replace.
:se is (incsearch, better put se is in your .vimrc)
/<search term>
check with n/N if you are happy with the matches
:s%//<replace term>/g
When omitting the <search term> in the search-replace in 4., the last used search will be used.
For acessing the list of last (search-replace) commands use q:, or as already noted q/ for the list of last search terms.
Bonus:
When using :se gd, s/<search>/<replace> will behave as s/<search>/<replace>/g.
Accessing just the first search match in each line can then still be done with adding /g, so essentially both behaviours are just switched.
/ and then up to bring up the last search query.

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