I'm writing a shell script to modify a file and I have a line something like this in it:
sed s/here \(.*\n\)/gone \1/g
Unfortunately, the search seems to match the longest string (i.e., it goes all the way to the last \n -- thus giving me just one replacement) but I want it to match only up to the first \n it finds (so I can get replacements on every line).
Is this possible?
Thanks for your help!
Looks like you want the feature called non-greedy (or lazy) match. Unfortunately sed does not provide such feature. To emulate it you need to search for anything except separator match until separator match. Like this:
s/here \([^\n]*\n\)/gone \1/g
Related
I have a file that is out-of-date and needs to be updated. The names have changed somewhat and I would like to clean them all up using a single substitution.
Here's what I'm trying to accomplish:
foo.foo_[single word] -> foo_bar.foo_[single word]_bar
where a single word is a string of n characters. In the file, they are always preceded by an underscore, but it needs to have "_bar" appended. There is always a "." after these instances, so I thought the following might work:
%s/foo\.foo_*\./foo_bar\.foo_*_bar\./g
Sadly, the first part doesn't even match what I want, so I'm back to square one.
I would first change:
foo_[word] -> foo_[word]_bar
and then
foo. -> foo_bar.
i.e.:
%s,\(foo_\w\+\),\1_bar,g|%s,foo\.,foo_bar\.,g
There are many ways to skin a cat but following should do the trick
%s/\vfoo.foo_(\w+)/foo_bar.foo_\1_bar/gc
what loosely translates to
\v Very Magic (:help magic)
foo.foo_ Search for exact string
(\w+) Search for a "word" and store in a backreference
/foo_bar.foo Replace search pattern with this exact string
\1 appended with backreference 1
_bar appended with _bar
or if you don't want to repeat the search in the replace part, you can go a bit nuts with backreferences and use
%s/\v(foo)\.foo_(\w+)/\1_bar.\1_\2_bar/gc
The most important parts you were missing were
using backreferences (:helpgrep backref)
using character classes (:h \w)
using repetition (_* is searching for 0 or more underscores. You probably meant _.*)
In Vim, I want to do a search and replace that includes:
[0-9]*
And in the replace part, I want whatever was in that vague range to be carried over and used.
For example let's say I have this:
getNumber(42).roundToTenth();
getNumber(43).roundToTenth();
getNumber(44).roundToTenth();
getNumber(45).roundToTenth();
getNumber(46).roundToTenth();
getNumber(47).roundToTenth();
and want to do a search and replace to change it to
DontGetNumber(42).roundDownTenth();
DontGetNumber(43).roundDownTenth();
DontGetNumber(44).roundDownTenth();
DontGetNumber(45).roundDownTenth();
DontGetNumber(46).roundDownTenth();
DontGetNumber(47).roundDownTenth();
How do I do that?
I think maybe you mean [0-9].* (number followed by zero or more characters). You can use capturing parentheses and use the backreference in the substitution.
s/[0-9]\(.*\)/\1/
The \1 will be whatever was captured. Change the replacement expression as needed.
s/getNumber(\([0-9]*\)).*/DontGetNumber(\1).roundDownTenth();
You really want to use search/replace for this?
Personnally, I'd rather do something like :%g/Number/norm! ^~IDont^[fT2sDown^[
use a record with q[register] and fill the part after norm! with c-r [register]
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.
I have several functions that start with get_ in my code:
get_num(...) , get_str(...)
I want to change them to get_*_struct(...).
Can I somehow match the get_* regex and then replace according to the pattern so that:
get_num(...) becomes get_num_struct(...),
get_str(...) becomes get_str_struct(...)
Can you also explain some logic behind it, because the theoretical regex aren't like the ones used in UNIX (or vi, are they different?) and I'm always struggling to figure them out.
This has to be done in the vi editor as this is main work tool.
Thanks!
To transform get_num(...) to get_num_struct(...), you need to capture the correct text in the input. And, you can't put the parentheses in the regular expression because you may need to match pointers to functions too, as in &get_distance, and uses in comments. However, and this depends partially on the fact that you are using vim and partially on how you need to keep the entire input together, I have checked that this works:
%s/get_\w\+/&_struct/g
On every line, find every expression starting with get_ and continuing with at least one letter, number, or underscore, and replace it with the entire matched string followed by _struct.
Darn it; I shouldn't answer these things on spec. Note that other regex engines might use \& instead of &. This depends on having magic set, which is default in vim.
For an alternate way to do it:
%s/get_\(\w*\)(/get_\1_struct(/g
What this does:
\w matches to any "word character"; \w* matches 0 or more word characters.
\(...\) tells vim to remember whatever matches .... So, \(w*\) means "match any number of word characters, and remember what you matched. You can then access it in the replacement with \1 (or \2 for the second, etc.)
So, the overall pattern get_\(\w*\)( looks for get_, followed by any number of word chars, followed by (.
The replacement then just does exactly what you want.
(Sorry if that was too verbose - not sure how comfortable you are with vim regex.)
It happens sometimes that I have to look into various log and trace files on Windows and generally I use for the purpose VIM.
My problem though is that I still can't find any analog of grep -v inside of VIM: find in the buffer a line not matching given regular expression. E.g. log file is filled with lines which somewhere in a middle contain phrase all is ok and I need to find first line which doesn't contain all is ok.
I can write a custom function for that, yet at the moment that seems to be an overkill and likely to be slower than a native solution.
Is there any easy way to do it in VIM?
I believe if you simply want to have your cursor end up at the first non-matching line you can use visual as the command in your global command. So:
:v/pattern/visual
will leave your cursor at the first non-matching line. Or:
:g/pattern/visual
will leave your cursor at the first matching line.
you can use negative look-behind operator #<!
e.g. to find all lines not containing "a", use /\v^.+(^.*a.*$)#<!$
(\v just causes some operators like ( and #<! not to must have been backslash escaped)
the simpler method is to delete all lines matching or not matching the pattern (:g/PATTERN/d or :g!/PATTERN/d respectively)
I'm often in your case, so to "clean" the logs files I use :
:g/all is ok/d
Your grep -v can be achieved with
:v/error/d
Which will remove all lines which does not contain error.
It's probably already too late, but I think that this should be said somewhere.
Vim (since version about 7.4) comes with a plugin called LogiPat, which makes searching for lines which don't contain some string really easy. So using this plugin finding the lines not containing all is ok is done like this:
:LogiPat !"all is ok"
And then you can jump between the matching (or in this case not matching) lines with n and N.
You can also use logical operations like & and | to join different strings in one pattern:
:LP !("foo"|"bar")&"baz"
LP is shorthand for LogiPat, and this command will search for lines that contain the word baz and don't contain neither foo nor bar.
I just managed a somewhat klutzy procedure using the "g" command:
:%g!/search/p
This says to print out the non-matching lines... not sure if that worked, but it did end up with the cursor positioned on the first non-matching line.
(substitute some other string for "search", of course)
You can search with following line and press n to jump to the first non-matching line
^\(.*all is ok\)\#!.*$
Breakdown of operators:
^ -> means start of the line
\( and \) -> To match a whole string multiple times, it must be grouped into one item. This is done by putting "\(" before it and "\)" after it.
\#! -> Matches with zero width if the preceding atom does NOT match at the current position.
.* -> Matches any character repeated 1 or more times
$ -> end of the line
Here is sample animation how it works. For simplicity I searched for word apple.
You can iterate through the non-matches using g and a null substitution:
:g!/pattern/s/^//c
If you reply "n" each time you wont even mark the file as changed.
You need ctrl-C to escape from the circle (or keep going to bottom of file).