how to understand below vim script entries? - vim

Question 1:
I only know the bash script like this let var = value, but how to understand the mean of the below grammar under vim?
let g:counter += 1
return g:counter . '. '
Question 2:
What’s the means by '<C-\>^>', what is the key sequence in vim?
map '<C-\>^>'
I want to append my question, please forgive me,
the vim key map is like this
map <C-\>^] :GtagsCursor<CR>
I press key like
Ctrl-\ Shift-. and press ]
this doesn't work, what's the matter?

Question 1:
the two lines should be in a function. otherwise the return doesn't make any sense.
also the global variable g:counter should be already defined.
then the first line, just does as same as:
let g:counter = g:counter+1
so increment the variable g:counter by 1.
The 2nd line:
return g:counter . '. '
for example, after increment, the variable value is 10, then the line returns a string 10. (space)
the first dot concatenates two strings. first string is the variable value, which is converted into string type automatically. and the second string is '. '
Question 2:
map <C-\>^>
Note that I took the single quote from your map command away.
The key sequence is:
Ctrl-\Shift-6Shift-.
shift-6 is ^
Shift-. is >

Regarding the first question, you should probably type :help eval.txt or :help usr_41.txt inside Vim and read a good chunk of it.

Related

How to replace a `\norm{ some string }` by `\| some string\|` quickly? [duplicate]

This question already has answers here:
Find and replace strings in vim on multiple lines
(11 answers)
Vim - Capture strings on Search and use on Replace
(4 answers)
Closed 3 years ago.
I am editing a markdown file with vim. This file exist many string \norm{ some string }. I want to replace them by \| some string \|. Does there exist any quick way? Thanks very much.
The answer in Find and replace strings in vim on multiple lines can not answer my question. It just talk about general replacing for one line and multi line. Here I want to replace a surrounding and keep the string in the surrounding.
What you're looking for are so-called capture groups and backreferences. Provided there are no nested forms (curly braces inside do not mean a problem in themselves) and forms spanning multiple lines, a quick solution could be: %s/\\norm {\(.*\)}/\\|\1\\|/g.
The \1 in the substitution part refers to the group captured by \(.*\), i.e. the original content inside the outermost pair of curly braces. See e.g. http://www.vimregex.com/#backreferences for more.
You could also use a macro to accomplish what you want.
Place your cursor on the first line that have the pattern you want to substitute. Then start recording the macro:
qq0ldwr|$xi\|ESCjq
Meaning:
qq = start recording a macro (q) in register q
0 = move to the beginning of the line
l = move one char to the right
dw = delete the word
r| = substitute what is under the cursor with a "|"
$ = move to the end of line
x = delete last char of the line
i = insert mode
\| = insert chars "\|"
ESC = exit insert mode
j = move to next line
q = stop recording
Execute the macro with:
#q
Execute the macro once again:
##
Keep doing it for as many lines as needed, or use:
<number>##
ex. 100##
To execute the macro number times.

vim change one occurrence alone in the line

I had a text like this
pid_t child;
long orig_eax;
child = fork();
if(child == 0) {
printf("the child is happy %d", child);
printf("the child");
I wanted to replace the word 'child' selectively using vim
so I used
%s/child/pid/c
so it asked me before replacing each match
but when it came to line 5 where there are two occurrences of 'child' , where I wanted to replace second one alone , so when it prompted to change first occurrence I gave 'n' , then instead asking the next occurrence in the same line it skipped the entire line and went to the next line.
Is this the expected behavior ?
If so how to ignore the first occurrence in the line but replace the second in the same line using the above search command ?
Add g ('global') modifier after the second / (along with the c (which stands for 'confirm')) : :%s/child/pid/cg
For more informations on flags, have a look at :help s_flags.
For instance, for the g flag :
[g] Replace all occurrences in the line. Without this argument,
replacement occurs only for the first occurrence in each line. If
the 'edcompatible' option is on, Vim remembers this flag and toggles
it each time you use it, but resets it when you give a new search
pattern. If the 'gdefault' option is on, this flag is on by default
and the [g] argument switches it off.

Get the length of the string in substitution

I'd like to calculate the length of a replace string used in a substitution. That is, "bar" in :s/foo/bar. Suppose I have access to this command string, I can run and undo it, and may separate the parts marked by / with split(). How would I get the string length of the replace string if it contains special characters like \1, \2 etc or ~?
For instance if I have
:s/\v(foo)|(bars)/\2\rreplace/
the replace length would be strlen("bars\rreplace") = 12.
EDIT: Just to be clear, I hope to use this to move the cursor past the text that was affected by a substitute operation. I'd appreciate alternative solutions as well.
You have to use :help sub-replace-expression. In it, you use submatch(2) instead of \2. If the expression is a custom function, you can as a side effect store the original length in a variable, and access that later:
function! Replace()
let g:replaceLength = strlen(submatch(0))
" Equivalent of \2\rreplace
return submatch(2) . "\r" . 'replace'
endfunction
:s/\v(foo)|(bars)/\=Replace()/

How to repeatedly add text on both sides of a word in vim?

I have a bunch of local variable references in a Python script that I want to pull from a dictionary instead. So, I need to essentially change foo, bar, and others into env['foo'], env['bar'] and so on. Do I need to write a regular expression and match each variable name to transform, or is there a more direct approach that I could just repeat with the . command?
You can use a macro: type these commands in one go (with spacing just to insert comments)
" first move to start of the relevant word (ie via search)
qa " record macro into the a register.
ienv['<esc> " insert relevant piece
ea'] " move to end of word and insert relevant piece
q " stop recording
then, when you're on the next word, just hit #a to replay the macro (or even ## to repeat the last replay after that).
There's an easier way - you can use a regex search and replace. Go into cmdline mode by typing a colon and then run this command:
%s/\\(foo\|bar\|baz\\)/env['\1']/
Replacing foo, bar, and baz with whatever your actual variable names are. You can add as many additional variables as you'd like, just be sure to escape your OR pipes with a backslash. Hope that helps.
you could write a function that would do this pretty well, add this to your .vimrc file:
function! s:surround()
let word = expand("<cword>")
let command = "%s/".word."/env[\'".word."\']/g"
execute command
endfunction
map cx :call <SID>surround()<CR>
This will surround every occurance of the word currently under the cursor.
If you wanted to specify what went before and after each instance you could use this:
function! s:surround()
let word = expand("<cword>")
let before = input("what should go before? ")
let after = input("what should go after? ")
let command = "%s/".word."/".before.word.after."/g"
execute command
endfunction
map cx :call <SID>surround()<CR>
If you only want to confirm each instance of the variable you could use this:
function! s:surround()
let word = expand("<cword>")
let before = input("what should go before? ")
let after = input("what should go after? ")
let command = "%s/".word."/".before.word.after."/c"
execute command
endfunction
map cx :call <SID>surround()<CR>
I figured out one way to do what I need. Use q{0-9a-zA-Z"} to record key strokes into a buffer. Position the cursor at the begging of the variable name, then cw and type env['']. Next move the cursor back one space to the last quote and paste the buffer filled from the cw command with P. Finally, reuse the recording with #{0-9a-z".=*} for each variable.

Vim: creating a C string literal around a block of text with vertically aligned quotes?

I would like to create a macro or a script in Vim that does the following:
wrap a block of text in double quotes
escaping any quotes that appear in the text itself
have the quotes on the right side in vertical alignment
For example:
<html>
<head></head>
<body>
<h1>High Score Server</h1>
<table>
ROWS
</table>
</body>
</html>
would become:
"<html> "
"<head></head> "
"<body> "
"<h1>High Score Server</h1>"
"<table> "
"ROWS "
"</table> "
"</body> "
"</html> ";
I am able to achieve this with a macro, but without the vertical alignment of the quotes on the right side. Can anyone help me with this one?
What I'd do :
With "surround" and "Align" plugins :
1) with cursor on first line (0,0), type <C-V>)$s"
2) then <S-V>):Align " and <Enter>.
Another solution without plugins :
1) set virtual mode
:set ve=all
2) <C-V> to go in block-wise selection, with cursor at the position 0,0
3) go down to the bottom of the text, then Shift-I, type " and Esc. This should prepend the quotes.
4) now go on the left end (since ve=all, you can go where there is no text)
5) <C-V>, go down to bottom, type r"
This is long to explain, but easy to do and reproduce. Also useful in lots of case.
function Enquote()
let [startline, endline]=sort([line("'<"), line("'>")])
let lines=getline(startline, endline)
let lengths=map(copy(lines), 'len(split(v:val, ''\zs''))')
let maxlen=max(lengths)
call map(lines, '''"''.v:val.repeat(" ", maxlen-lengths[v:key]).''"''')
return setline(startline, lines)
endfunction
Explanation:
line("'<") and line("'>") get the line numbers of start and end of last visual selection.
sort([...]) sorts this line numbers since you may have started selecting lines from the end of the selection.
let [a, b]=[c, d] is a parallel assignment: sort will produce a sorted list of two items, where first item is lesser or equal to second item. Obviously, lesser is a first selected line.
len(split(v:val, '\zs')) is an advanced strlen() which supports unicode.
max(list) finds a maximum value. Obvious.
So, map(copy(lines), 'len(split(v:val, ''\zs''))') applies this strlen to all items in list. copy() is required since we do not want our list to be modified.
map(lines, '''"''.v:val.repeat(" ", maxlen-lengths[v:key]).''"''') modifies an lines in a way you require. I switched from printf to repeat because printf does not handle multibyte characters correctly (by «correctly» I mean that «¥» is one character long, while printf considers it two bytes long).
setlines(linenumber, listoflines) actually modifies buffer.
Making use of the unix program "par" to do this may well solve your problem. There's a Vimcast showing how to integrate it into vim over at http://vimcasts.org/episodes/formatting-text-with-par/
Is it possible to make two passes over the list of lines in vim script? Then you can do something like this (pseudocode):
let N = length of longest line
for each line L:
insert a " character at the beginning
append N - len(L) spaces
append a " character
best i got is a 3-pass regex.
select block in visual mode, then use:
:'<,'>s#^#"#
:'<,'>s#$# #
:'<,'>s#\(.\{28\}\).*#\1"
with the 28 being the length of your longest line.
By all means heed the previous answers and get your vim-fu in shape. Or install/modify/poke-the-author of this plugin:
http://www.vim.org/scripts/script.php?script_id=4727
From the plugin's page:
This script converts multi-line text in a C++ file to a multi-line
string literal, escaping the quote and tab characters. It also does
the reverse conversion, un-escaping some characters. It's not too
complete for now, but it will be someday if needs come.
If you need to make changes use the source-code repository:
https://bitbucket.org/dsign/stringliteral.vim
In two passes:
let l = max(map(getline("'<", "'>"), 'strwidth(v:val)'))
'<,'>s/.*/\=('"'.submatch(0).repeat(' ', l-strwidth(submatch(0)) )).'"'

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