How to replace in vim - vim

I have a line in a source file: [12 13 15]. In vim, I type:
:%s/\([0-90-9]\) /\0, /g
wanting to add a coma after 12 and 13. It works, but not quite, as it inserts an extraspace [12 , 13 , 15].
How can I achieve the desired effect?

Use \1 in the replacement expression, not \0.
\1 is the text captured by the first \(...\). If there were any more pairs of escaped parens in your pattern, \2 would match the text capture between the pair starting at the second \(, \3 at the third \(, and so on.
\0 is the entire text matched by the whole pattern, whether in parentheses or not. In your case this includes the space at the end of your pattern.
Also note that [0-90-9] is the same as [0-9]: each [...] collection matches just one character. It happens to work anyway, because in your data ‘a digit followed by a space’ matches in the same places as ‘2 digits followed by a space’. (If you actually needed to only insert commas after 2 digits, you could write [0-9][0-9].)

"I have a line in a source file:..."
then you type :%s/... this will do the substitution on all lines, if it matched. or that is the single line in your file?
If it is the single line, you don't have to group, or [0-9], just :%s/ \+/,/g will do the job.

The fine answers already point interesting solutions, but here's another one,
making use of the \zs, which marks the start of the match. In this pattern:
/[0-9]\zs /
The searched text is /[0-9] /, but only the space counts as a match. Note
that you can use the class \d to simplify the digit character class, so the
following command shall work for your needs:
:s/\d\d\zs /, /g ; matches only the space, replace by `, '
You said you have multiple lines and these changes are only to certain lines.
You can either visually select the lines to be changed or use the :global
command, which searches for lines matching a pattern and applies a command to
them. Now you'd need to build an expression to match the lines to be changed
in a less precise as possible way. If the lines that begins with optional
spaces, a [ and two digits are the only lines to be matched and no other
ones, then this would work for you:
:g/\s*[\d\d/s/\d\d\zs /, /g
Check the help for pattern.txt for \ze and similar and
:global.
Homework: use the help to understand \zs and see how this works:
:s/\d\d\zs\ze /,/g

Related

how to remove specific characters in vi or vim editor

I have some txt in vi:
|NC_004718|29751nt|SARS
|NC_045512|29903nt|Severe
|NC_004718|29751nt|SARS
|NC_045512|29903nt|Severe
|NC_004718|29751nt|SARS
now I want to replace remove everything after NC_004718, my expected output is:
NC_004718
NC_045512
NC_004718
NC_045512
NC_004718
How to do it? Thanks.
I would recommend using a substitution with regular expression to match the entire string and to capture what you would like to keep in parentheses. That way you can then replace the entire string with just the match.
:%s/^|\([^|]\+\)|.\+/\1/
To break down what is happening:
% means that you want to apply the command to each line within the file.
s means that you are doing substitution command (on each line). The s command has a syntax of s/<regular expression pattern>/<replacement>/<flags>
The regular eression pattern in the above command is ^|\([^|]\+\)|.\+.
^ means match from the line start.
| matches the character |.
\([^|]\+\) matches all characters except for the character |. Note that the real regular expression is actually ([^|]+), the additional \ characters are there because Vim needs to know that they are intended to be special characters for processing and not exact characters it needs to match. Also note that the parentheses are there to capture the match into a group (see below).
| again matches the actual character |.
.\+ matches all characters until the end of the line. Note that the . is considered special character by default but + still needs a preceding \.
The replacement text is only \1. This denotes that Vim should replace the text with whatever was captured in the first group (i.e. the first set of parentheses).
There are no flags with this command so there is nothing after the last /.
For example,
:g/NC_\d\+/normal! ygnV]p
:g/regex/ to match lines
normal! to execute Normal mode commands
ygn to yank the text previously matched by :g
V to select the whole line
]p or p to replace the line with the match
If you have only lines like those you have shown try:
:%norm xf|D

How to create a line break after each 3 characters in one long line?

I want to break the below line into 1000 ones by 3 letters each:
saahaalaasabaaboabsabyaceactaddadoadsadzaffaftagaageagoagsahaahiahsaidailaimainairaisaitalaalbaleallalpalsaltamaamiampamuanaandaneaniantanyapeapoappaptarbarcarearfarkarmarsartashaskaspassateattaukavaaveavoawaaweawlawnaxeayeaysazobaabadbagbahbalbambanbapbarbasbatbaybedbeebegbelbenbesbetbeybibbidbigbinbiobisbitbizboabobbodbogboobopbosbotbowboxboybrabrobrrbubbudbugbumbunburbusbutbuybyebyscabcadcamcancapcarcatcawcayceecelcepchicigciscobcodcogcolconcoocopcorcoscotcowcoxcoycozcrucrycubcudcuecumcupcurcutcwmdabdaddagdahdakdaldamdandapdawdaydebdeedefdeldendevdewdexdeydibdiddiedifdigdimdindipdisditdocdoedogdoldomdondordosdotdowdrydubdudduedugduhduidunduodupdyeeareateauebbecuedhedseekeeleffefsefteggegoekeeldelfelkellelmelsemeemsemuendengenseoneraereergernerrersessetaetheveeweeyefabfadfagfanfarfasfatfaxfayfedfeefehfemfenferfesfetfeufewfeyfezfibfidfiefigfilfinfirfitfixfizfluflyfobfoefogfohfonfopforfoufoxfoyfrofryfubfudfugfunfurgabgadgaegaggalgamgangapgargasgatgaygedgeegelgemgengetgeyghigibgidgiegiggingipgitgnugoagobgodgoogorgosgotgoxgoygulgumgungutguvguygymgyphadhaehaghahhajhamhaohaphashathawhayhehhemhenhepherheshethewhexheyhichidhiehimhinhiphishithmmhobhodhoehoghonhophoshothowhoyhubhuehughuhhumhunhuphuthypiceichickicyidsiffifsiggilkillimpinkinninsionireirkismitsivyjabjagjamjarjawjayjeejetjeujewjibjigjinjobjoejogjotjowjoyjugjunjusjutkabkaekafkaskatkaykeakefkegkenkepkexkeykhikidkifkinkipkirkiskitkoakobkoikopkorkoskuekyelablacladlaglamlaplarlaslatlavlawlaxlaylealedleelegleileklesletleulevlexleylezliblidlielinliplislitlobloglooloplotlowloxluglumluvluxlyemacmadmaemagmanmapmarmasmatmawmaxmaymedmegmelmemmenmetmewmhomibmicmidmigmilmimmirmismixmoamobmocmodmogmolmommonmoomopmormosmotmowmudmugmummunmusmutmycnabnaenagnahnamnannapnawnaynebneenegnetnewnibnilnimnipnitnixnobnodnognohnomnoonornosnotnownthnubnunnusnutoafoakoaroatobaobeobiocaodaoddodeodsoesoffoftohmohoohsoilokaokeoldoleomsoneonoonsoohootopeopsoptoraorborcoreorsortoseoudouroutovaoweowlownoxooxypacpadpahpalpampanpapparpaspatpawpaxpaypeapecpedpeepegpehpenpepperpespetpewphiphtpiapicpiepigpinpippispitpiupixplypodpohpoipolpompoopoppotpowpoxproprypsipstpubpudpugpulpunpuppurpusputpyapyepyxqatqisquaradragrahrairajramranraprasratrawraxrayrebrecredreerefregreiremrepresretrevrexrhoriaribridrifrigrimrinriprobrocrodroeromrotrowrubruerugrumrunrutryaryesabsacsadsaesagsalsapsatsausawsaxsayseasecseesegseiselsensersetsewsexshasheshhshysibsicsimsinsipsirsissitsixskaskiskyslysobsodsolsomsonsopsossotsousowsoxsoyspaspysristysubsuesuksumsunsupsuqsyntabtadtaetagtajtamtantaotaptartastattautavtawtaxteatedteetegteltentettewthethothytictietiltintiptistittodtoetogtomtontootoptortottowtoytrytsktubtugtuituntuptuttuxtwatwotyeudoughukeuluummumpunsupoupsurburdurnurpuseutauteutsvacvanvarvasvatvauvavvawveevegvetvexviavidvievigvimvisvoevowvoxvugvumwabwadwaewagwanwapwarwaswatwawwaxwaywebwedweewenwetwhawhowhywigwinwiswitwizwoewogwokwonwoowopwoswotwowwrywudwyewynxisyagyahyakyamyapyaryawyayyeayehyenyepyesyetyewyidyinyipyobyodyokyomyonyouyowyukyumyupzagzapzaszaxzedzeezekzepzigzinzipzitzoazoozuzzzz
Please advise me on how to approach it.
Try the following find and replace, in regex mode:
Find: (...)(?=.)
Replace: $1\r\n
Demo
The pattern (...)(?=.) matches and captures any three letters at a time. Then, we replace with those three letters ($1) followed by a break (I used \r\n, the Windows line ending; use \n if you are on Linux). Note that the pattern also only matches if the three letters found are not the final three letters in the string. The positive lookahead (?=.) avoids adding an unwanted break at the end.
This regular expression,
.{3}\K
with a replacement of:
\n
might simply do that.
The expression is explained on the top right panel of this demo if you wish to explore/simplify/modify it.

VIM: can't fully understand this substitution

I have taken this line of code from a book to format html code into a string-concatenated form for use in javascript in vim. I can't seem to understand what the numbers '1' and '2 represent and what the question marks are for at the end of the regexes. I'm used to seeing substitutions like %s/foo/bar/g, so the absence of forward slashes confuses me a bit. Summarized, I don't understand the '1' and '2', the question marks after the dollar sign and before the carriage return, and why the forward slashes are not used.
vmap <silent> ;q :s?^\(\s*\)\(.*\)\s*$? \1 + '\2'?<CR>
Forward slashes are typically used as the separator, but the substitute command uses the first character after the 's' as the separator, allowing it to be changed to anything. It seems the author thought that all the slashes might be confusing, so changed it to a '?'. This is how the command would appear with the more traditional forward slashes:
:s/^\(\s*\)\(.*\)\s*$/ \1 + '\2'/<CR>
So the above would mean, search forward, finding lines starting with any amount of whitespace, followed by any number of any characters, and any amount of whitespace, and then substitute it for <space><the first whitespace><space>+<space>'<the other characters>'. I think it was intending to strip any trailing whitespace, but in my testing it doesn't do that, because the .* will match everything to the end of the line.
As it was said in other answers, the / delimiter can be replaced by some other char : when many slashes are used in the command, it may be more clear; see a question about it, https://stackoverflow.com/a/36568901/3271687.
\1, \2, \n... match the nth sub-expression used in the pattern. A sub-expression is defined with \( and \). So in your example:
:s?^\(\s*\)\(.*\)\s*$? \1 + '\2'?
\s* --> note that this part can't be reached, it's useless
, \1 is replaced by the spaces found in \(\s*\), and \2 is replaced by all the chars (the whole rest of the line) found in \(.*\).

Substitute `number` with `(number)` in multiple lines

I am a beginner at Vim and I've been reading about substitution but I haven't found an answer to this question.
Let's say I have some numbers in a file like so:
1
2
3
And I want to get:
(1)
(2)
(3)
I think the command should resemble something like :s:\d\+:........ Also, what's the difference between :s/foo/bar and :s:foo:bar ?
Thanks
Here is an alternative, slightly less verbose, solution:
:%s/^\d\+/(&)
Explanation:
^ anchors the pattern to the beginning of the line
\d is the atom that covers 0123456789
\+ matches one or more of the preceding item
& is a shorthand for \0, the whole match
Let me address those in reverse.
First: there's no difference between :s/foo/bar and :s:foo:bar; whatever delimiter you use after the s, vim will expect you to use from then on. This can be nice if you have a substitution involving lots of slashes, for instance.
For the first: to do this to the first number on the current line (assuming no commas, decimal places, etc), you could do
:s:\(\d\+\):(\1)
The \(...\) doesn't change what is matched - rather, it tells vim to remember whatever matched what is inside, and store it. The first \(...\) is stored in \1, the second in \2, etc. So, when you do the replacement, you can reference \1 to get the number back.
If you want to change ALL numbers on the current line, change it to
:s:\(\d\+\):(\1):g
If you want to change ALL numbers on ALL lines, change it to
:%s:\(\d\+\):(\1):g
You can do what you want with:
:%s/\([0-9]\)/(\1)/
%s means global search and replace, that is do the search/replace for every line in the file. the \( \) defines a group, which in turn is referenced by \1. So the above search and replace, finds all lines with a single digit ([0-9]), and replaces it with the matched digit surrounded by parentheses.

What vim pattern matches a number which ends with dot?

In PDP11/40 assembling language a number ends with dot is interpreted as a decimal number.
I use the following pattern but fail to match that notation, for example, 8.:
syn match asmpdp11DecNumber /\<[0-9]\+\.\>/
When I replace \. with D the pattern can match 8D without any problem. Could anyone tell me what is wrong with my "end-with-dot" pattern? Thanks.
Your regular expression syntax is fine (well, you can use \d instead of [0-9]), but your 'iskeyword' value does not include the period ., so you cannot match the end-of-word (\>) after it.
It looks like you're writing a syntax for a custom filetype. One option is to
:setlocal filetype+=.
in a corresponding ~/.vim/ftplugin/asmpdp11.vim filetype plugin. Do this when the period character is considered a keyword character in your syntax.
Otherwise, drop the \> to make the regular expression match. If you want to ensure that there's no non-whitespace character after the period, you can assert that condition after the match, e.g. like this:
:syn match asmpdp11DecNumber /\<\d\+\.\S\#!/
Note that a word is defined by vim as:
A word consists of a sequence of letters, digits and underscores, or a
sequence of other non-blank characters, separated with white space
(spaces, tabs, ). This can be changed with the 'iskeyword'
option. An empty line is also considered to be a word.
so your pattern works fine if whitespace follows the number. You may want to skip the \>.
I think the problem is your end-of-word boundary marker. Try this:
syn match asmpdp11DecNumber /\<[0-9]\+\./
Note that I have removed the \> end-of-word boundary. I'm not sure what that was in there for, but it appears to work if you remove it. A . is not considered part of a word, which is why your version fails.

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