When i need to replace a string with a new string in vim.
First i would use search-mode to check that the search pattern is correct.
/search pattern
Then use the 's' command to do substitution.
:%s/search pattern/new string/
The search pattern need to type twice. If it is too complex, it would be boring.
Is there a method to avoid this?
You can simply omit the pattern in the substitution command, e.g.
:%s//new string/
This is documented in :help last-pattern (emphasis mine):
The last used pattern and offset are remembered. They can be used to
repeat the search, possibly in another direction or with another
count. Note that two patterns are remembered: One for 'normal' search
commands and one for the substitute command ":s". Each time an empty
pattern is given, the previously used pattern is used.
Also (in addition to Marco Baldelli's correct answer), the last search pattern is stored in the special register /. You can insert this in the command-line via Ctrl + R, followed by /. (This also works in insert mode, and also with other registers.) It's helpful when you want to tweak your search pattern before substituting.
Related
When I type /foo and then enter, is there a way to mark occurrence for all highlighted words? Right now, the /search seems pretty useless compared to the regular atom search, since it only highlights but doesn't let you replace.
The key / is used for searching, whereas :s for substitutions (i.e. replacements). So to replace foo with bar you can do:
:%s/foo/bar/gc
Here % means look for replacements in the entire file, and the last gc are replacement flags. The Vim documentation provides a great explanation of the topic and it can be accessed by typing :help subs. To learn more about replacement flags: :h flags.
Some more suggestions for a good workflow (at least in Vim itself):
After using /foo to locate a match, and you only want to replace that one: As the cursor is at the start of the match, you can use ce, cE or more generally cgn (gn selects the current / next match; it's a recent addition in version 8.0).
If you want to replace all matches, you don't need to repeat the search pattern in the :substitute command; an empty {pattern} there will recall the search pattern. So, you can briefly write :%s//bar/g (+ c to interactively influence replacements).
It seems I can't mark occurrence if I press enter. However, I can do some things if I haven't pressed enter.
cmd-o marks all search occurrences
ctr-cmd-c waits for you to specify a range, and then changes all search occurrences
The exact problem: I have a source in C++ and I need to replace a symbol name to some other name. However, I need that this replace the symbol only, not accidentally the same looking word in comments or text in "".
The source information what particular language section it is, is enough defined in the syntax highlighting rules. I know they can fail sometimes, but let's state this isn't a problem. I need some way to walk through all found occurrences of the phrase, then check in which section it is found, and if it's text or comment, this phrase should be skipped. Otherwise the replacement should be done either immediately, or by asking first, depending on well known c flag.
What I imagine would be at least theoretically possible is:
Having a kinda "callback" when doing substitution (called for each phrase found, and requesting the answer whether to substitute or not), or extract the list of positions where the phrase has been found, then iterate through all of them
Extract the name of the current "hi-linked" syntax highlighting rule, which is used to color the text at given position
Is it at all possible within the current features of vim?
Yes, with a :help sub-replace-expression, you can evaluate arbitrary expressions in the replacement part of :substitute. Vim's synID() and synstack() functions allow you to get the current syntax element.
Luc Hermitte has an implementation that omits replacement inside strings, here. You can easily adapt this to your use case.
With the help of my ingo-library plugin, you can define a short predicate function, e.g. matching comments and constants (strings, numbers, etc.):
function! CommentOrConstant()
return ingo#syntaxitem#IsOnSyntax(getpos('.'), '^\%(Comment\|Constant\)$')
endfunction
My PatternsOnText plugin now provides a :SubstituteIf command that works like :substitute, but also takes a predicate expression. With that, it's very easy to do a replacement anywhere except in comments or constants:
:%SubstituteIf/pattern/replacement/g !CommentOrConstant()
In vi (from cygwin), when I do searching:
:%s/something
It just replaces the something with empty string like
:%s/something// .
I've googled for a while but nothing really mentions this. Is there anything I should add to the .vimrc or .exrc to make this work?
Thanks!
In vi and vim, when you search for a pattern, you can search it again by simply typing /. It is understood that the previous pattern has to be used when no pattern is specified for searching.
(Though, you can press n for finding next occurence)
Same way, when you give a source (pattern) and leave the replacement in substitute command, it assumes that the replacement is empty and hence the given pattern is replaced with no characters (in other words, the pattern is removed)
In your case, you should understand that % stand for whole file(buffer) and s for substitute. To search, you can simply use /, followed by a pattern. To substitute , you will use :s. You need not confuse searching and substituting. Hence, no need for such settings in ~/.exrc. Also, remember that / is enough to search the whole buffer and % isnt necessary with /. / searches the entire buffer implicitly.
You may also want to look at :g/Pattern/. Learn more about it by searching :help global or :help :g in command line.
The format of a substitution in vim is as follows:
:[range]s[ubstitute]/{pattern}/{string}/[flags] [count]
In your case you have omitted the string from the substitution command and here what vim documentation stated about it:
If the {string} is omitted the substitute is done as if it's empty.
Thus the matched pattern is deleted. The separator after {pattern}
can also be left out then. Example: >
:%s/TESTING This deletes "TESTING" from all lines, but only one per line.
For compatibility with Vi these two exceptions are allowed:
"/{string}/" and "\?{string}?" do the same as "//{string}/r".
"\&{string}&" does the same as "//{string}/".
E146
Instead of the '/' which surrounds the pattern and replacement string, you can
use any other single-byte character, but not an alphanumeric
character, '\', '"' or '|'. This is useful if you want to include a
'/' in the search pattern or replacement string. Example: >
:s+/+//+
In other words :%s/something and :%s;something or :%s,something have all the same behavior because the / ; and , in the last examples are considered only as SIMPLE SEPARATOR
Most substitution commands in vim perform an action on a full line or a set of lines, but I would like to only do this on part of a line (either from the cursor to end of the line or between set marks).
example
this_is_a_sentence_that_has_underscores = this_is_a_sentence_that_should_not_have_underscores
into
this_is_a_sentence_that_has_underscores = this is a sentence that should not have underscores
This task is very easy to do for the whole line :s/_/ /g, but seems to be much more difficult to only perform the replacement for anything after the =.
Can :substitution perform an action on half of a line?
Two solutions I can think of.
Option one, use the before/after column match atoms \%>123c and \%<456c.
In your example, the following command substitutes underscores only in the second word, between columns 42 and 94:
:s/\%>42c_\%<94c/ /g
Option two, use the Visual area match atom \%V.
In your example, Visual-select the second long word, leave Visual mode, then execute the following substitution:
:s/\%V_/ /g
These regular expression atoms are documented at :h /\%c and :h /\%V respectively.
Look-around
There is a big clue your post already:
only perform the replacement for anything after the =.
This often means using a positive look-behind, \#<=.
:%s/\(=.*\)\#<=_/ /g
This means match all _ that are after the following pattern =.*. Since all look-arounds (look-aheads and look-behinds) are zero width they do not take up space in the match and the replacement is simple.
Note: This is equivalent to (?<=...) in perl speak. See :h perl-patterns.
What about \zs?
\zs will set the start of a match at a certain point. On the face this sounds exactly what is needed. However \zs will not work correctly as it matches the pattern before the \zs first then the following pattern. This means there will only be one match. Look-behinds on the other hand match the part after \#<= then "look behind" to make sure the match is valid which makes it great for multiple replacement scenario.
It should be noted that if you can use \zs not only is it easy to type but it is also more efficient.
Note: \zs is like \K in perl speak.
More ways?!?
As #glts mentioned you can use other zero-width atoms to basically "anchor" your pattern. A list of a few common ways:
\%>a - after the 'a mark
\%V - match inside the visual area
\%>42c - match after column 42
The possible downside of using one of these methods they need you to set marks or count columns. There is nothing wrong with this but it means the substitution will maybe affected by side-effects so repeating the substitution may not work correctly.
For more help see:
:h /\#<=
:h /zero-width
:h perl-patterns
:h /\zs
The search command in vim allows you to place the cursor relative to the search results. For example, /hello/b+2 places the cursor on the first l.
How do I do that with the substitute command?
s/hello/b+2/_/
does not work.
I need this to replace not the entire search string, but a portion of it only (specifically, to blank out all but the first character of a word).
You generally have two options: similar to other regex engines zero-width matches (though with different syntax):
:s/\(he\)\#<=llo/_/
or vim-specific “set the start of the match here”:
:s/he\zsllo/_/
. Also, there is a workaround which will look similar in almost every other regex engine:
:s/\(he\)llo/\1_/
: this captures text that should be unchanged and makes replacement include it.