This is my first post on stackoverflow, so please be gentle with me...
I am still learning regex - mostly because I have finally discovered how useful they can be and this is in part through using Sublime Text 2. So this is Perl regex (I believe)
I have done searching on this and other sites but I am now genuinely stuck. Maybe I am trying to do something that can't be done
I would like to find a regex (pattern) that will let me find the function or method or procedure etc that contains a given variable or method call.
I have tried a number of expressions and they seem to get part of the way but not all the way. Particularly when searching in Javascript I pick up multiple function declarations instead of the one nearest to the call/variable that I am looking for.
for example:
I am looking for the function that calls the method save data()
I have learnt, from this excellent site that I can use (?s) to switch . to include newlines
function.*(?=(?s).*?savedata\(\))
however, that will find the first instance of the word function and then all the text unto and including savedata()
if there are multiple procedures then it will start at the next function and repeat until it gets to savedata() again
function(?s).*?savedata\(\) does something similar
I have tried asking it to ignore the second function (I believe) by using something like:
function(?s).*?(?:(?!function).*?)*savedata\(\)
But that doesn't work.
I have done some investigation with look forwards and look backwards but either I am doing it wrong (highly possible) or they are not the right thing.
In summary (I guess), how do I go backwards, from a given word to the nearest occurrence of a different word.
At the moment I am using this to search through some javascript files to try and understand the structure/calls etc but ultimately I am hoping to use on c# files and some vb.net files
Many thanks in advance
Thanks for the swift responses and sorry for not added an example block of code - which I will do now (modified but still sufficient to show the issue)
if I have a simple block of javascript like the following:
function a_CellClickHandler(gridName, cellId, button){
var stuffhappenshere;
var and here;
if(something or other){
if (anothertest) {
event.returnValue=false;
event.cancelBubble=true;
return true;
}
else{
event.returnValue=false;
event.cancelBubble=true;
return true;
}
}
}
function a_DblClickHandler(gridName, cellId){
var userRow = rowfromsomewhere;
var userCell = cellfromsomewhereelse;
//this will need to save the local data before allowing any inserts to ensure that they are inserted in the correct place
if (checkforarangeofthings){
if (differenttest) {
InsSeqNum = insertnumbervalue;
InsRowID = arow.getValue()
blnWasInsert = true;
blnWasDoubleClick = true;
SaveData();
}
}
}
running the regex against this - including the second one that was identified as should be working Sublime Text 2 will select everything from the first function through to SaveData()
I would like to be able to get to just the dblClickHandler in this case - not both.
Hopefully this code snippet will add some clarity and sorry for not posting originally as I hoped a standard code file would suffice.
This regex will find every Javascript function containing the SaveData method:
(?<=[\r\n])([\t ]*+)function[^\r\n]*+[\r\n]++(?:(?!\1\})[^\r\n]*+[\r\n]++)*?[^\r\n]*?\bSaveData\(\)
It will match all the lines in the function up to, and including, the first line containing the SaveData method.
Caveat:
The source code must have well-formed indentation for this to work, as the regex uses matching indentations to detect the end of functions.
Will not match a function if it starts on the first line of the file.
Explanation:
(?<=[\r\n]) Start at the beginning of a line
([\t ]*+) Capture the indentation of that line in Capture Group 1
function[^\r\n]*+[\r\n]++ Match the rest of the declaration line of the function
(?:(?!\1\})[^\r\n]*+[\r\n]++)*? Match more lines (lazily) which are not the last line of the function, until:
[^\r\n]*?\bSaveData\(\) Match the first line of the function containing the SaveData method call
Note: The *+ and ++ are possessive quantifiers, only used to speed up execution.
EDIT:
Fixed two minor problems with the regex.
EDIT:
Fixed another minor problem with the regex.
Related
I am using an Engineering Program which lets me Code formulas in order to filter out specific lines in a database. I am trying to look for a certain line in the database which contains e.g. "concrete" as a property.
In the Code I can use regular expressions.
The regex I was using so far looked like this:
".*(concrete).*";
so if the line in the database contains concrete, I will get the wanted result.
Now the Problem is: i would like to switch the word concrete with a variable, so that it Looks like this:
".*(#VARIABLE1).*";
(the Syntax with the # works in the program btw.)
the Problem is: if i set the variable as concrete, the program automatically switches it for 'concrete' . Obviously, the word concrete cant be found anymore, since the searchterm now contains the two ' Symbols in the beginning and i the end.
Is there a way to ignore those two characters using the Right regex?
what I want it to do is the following:
If a line in the database contains "25cm concrete in Grey"
I should get a match from the regex.
with the searchterm ".*(concrete).*"; it works, with the variable ".*(#VARIABLE1).*"; it doesnt.
EDIT:
the whole "Formula" in the program Looks like that:
if(Match(QTO(Typ:="Attribut{FloorsLayer_02_MaterialName}");".*(#V_QUALITY).*" ;"regex") ;QTO(Typ:="Attribut{Fläche}");0)
I want the if-condition to be true, when the match inside is true.
the whole QTO function is just the programs Syntax to use a certain Attribute into the match-function, the middle part is my Problem. I really don't know the programming language or anything,I'm new to this. hope it helps!
Thats more of a hack than a real solution and i'm not sure if it even works:
if you use the regex
.*(#VARIABLE1)?).*
and the string ?concrete(
this will result in a regex looking like this:
.*('?concrete(')?).*
which makes the additional characters optional.
This uses the following assumtption:
the string (#VARIABLE1) gets replaced by the ('<content of VARIABLE1>')
I am trying to search a text file that will return a result if more than one word is found in that line. I don't see this explained in the documentation and I have tried various loops with no success.
What I would like to do is something similar to this:
$read(name.txt, s, word1|word2|word3)
or even something like this:
$read(name.txt, w, word1*|*word2*|*word3)
I don't know RegEx that well so I'm assuming this can be done with that but I don't know how to do that.
The documentation in the client self is good but I also recommend this site: http://en.wikichip.org/wiki/mirc. And with your problem there is a nice article : http://en.wikichip.org/wiki/mirc/text_files
All the info is taken from there. So credits to wikichip.
alias testForString {
while ($read(file.txt, nw, *test*, $calc($readn + 1))) {
var %line = $v1
; you can add your own words in the regex, seperate them with a pipe (|)
noop $regex(%line,/(word1|word2|word3|test)/))
echo -a Amount of results: $regml(0)
}
}
$readn is an identifier that returns the line that $read() matched. It is used to start searching for the pattern on the next line. Which is in this case test.
In the code above, $readn starts at 0. We use $calc() to start at line 1. Every match $read() will start searching on the next line. When no more matches are after the line specified $read will return $null - terminating the loop.
The w switch is used to use a wildcard in your search
The n switch prevents evaluating the text it reads as if it was mSL code. In almost EVERY case you must use the n switch. Except if you really need it. Improper use of the $read() identifier without the 'n' switch could leave your script highly vulnerable.
The result is stored in a variable named %line to use it later in case you need it.
After that we use a noop to execute a regex to match your needs. In this case you can use $regml(0) to find the amount of matches which are specified in your regex search. Using an if-statement you can see if there are two or more matches.
Hope you find this helpful, if there's anything unclear, I will try to explain it better.
EDIT
#cp022
I can't comment, so I'll post my comment here, so how does that help in any way to read content from a text file?
I have looked at multiple solutions here for similar tasks, and tried them in different ways.
Essentially, I have a cells with long, somewhat similar strings of text, and I want to isolate specific text markers in order to be able to split on those markers. The specific string I am looking for is "MHPP" and I want to replace it with "][MHPP " so I can used the split function to split on the "]".
I was able to get it to work by manually Finding and Replacing (CTRL+F and selecting parameters for the replace), but I want to be able to script it because I won't be the one running the script and need to simplify the process for low-information users.
Using =replace(find("MHPP"),7,"][MHPP ") only finds the first instance of the find value, and there may be multiple usages of the term throughout the cell.
Any suggestions? I suppose there might be a way to write the cell to a string, and replace within the array, but the logic of that process is escaping me at the moment.
I'm not asking for the entire code. I can activate the sheet, get the range, and work from there, but I just don't know how to write the specific function findAndReplace() that would actually locate all repetitions of the string and replace them all.
I'm also open to importing the .csv into a different format, running a function there, and returning it back out to a .csv, but that hasn't proven to be very fruitful either in my searches.
Thanks for any guidance you can offer to get me on the right path.
You can use the replace string function on every cell in a global iteration of your sheet, do that at array level to keep it fast and simple.
The code itself can be very short and straightforward like this :
function myFunction() {
var sh = SpreadsheetApp.getActive();
var data = sh.getDataRange().getValues();// get all data
for(var n=0;n<data.length;n++){
for(var m=0;m<data[0].length;m++){
if(typeof(data[n][m])=='string'){ // if it is a string
data[n][m]=data[n][m].replace(/MHPP/g,'][MHPP');// use the regex replace with /g parameter meaning "globally"
}
}
}
sh.getDataRange().setValues(data);// update sheet values
}
This could be improved to take care of certain situations where the script would be executed twice (or more) to prevent replacement if '][' is already present... I'll let you manage these details.
I have a txt file with content
$NETS
P3V3_AUX_LGATE; PQ6.8 PU37.2
U335_PIN1; R3328.1 U335.1
$END
need to be updated in this format, and save back to another txt file
$NETS
'P3V3_AUX_LGATE'; PQ6.8 PU37.2
'U335_PIN1'; R3328.1 U335.1
$END
NOTE: number of lines may go up to 10,000 lines
My current solution is to read the txt file line by line, detect the presence of the ";" and newline character and do the changes.
Right now i have a variable that holds ALL the lines, is there other way something like Replace via RegEx to do the changes without looping thru each line, this way i can readily print the result
and follow up question, which one is more efficient?
Try
ResultString = Regex.Replace(SubjectString, "^([^;\r\n]+);", "'$1';", RegexOptions.Multiline)
on your multiline string.
This will find any string (length one or more) at the start of a line up until the first semicolon if there is one and replace it with its quoted equivalent.
It should be more efficient than looping through the string line by line as you're doing now, but if you're in doubt, you'd have to profile it.
You could probably find all the matches using something like \w+; but I don't know how you'd be able to do a replace on that using Regex.Replace to add the 's but keep the original match.
However, if you already have it as one variable, you don't have to read the file again, either you could make your code find all ;s and then find the previous newline for each, or you could use a String.Split on newlines to split the variable you've already got into lines.
And if you want to get it back to one variable you can just use String.Join.
Personally I'd normally use the String.Split (and possibly the String.Join if needed) method, since I think that would make the code easy to read.
I would say Yes! this can be done with Regular expressions. Make sure you got the "multiline" option turned on and craft your regular expression using some capture groups to ease the work.
I can however say this will NOT be the optimal one. Since you mention the amount of lines you could be processing, it seems 'resource wise' smarter to use a streaming approach instead of the in memory approach.
Taking the Regex approach (and this took 15 mins so please don't think this is an optimal solution, just prove it would work)
private static Regex matcher = new Regex(#"^\$NETS\r\n(?<entrytitle>.[^;]*);\s*(?<entryrest>.*)\r\n(?<entrytitle2>.[^;]*);\s*(?<entryrest2>.*)\r\n\$END\r\n", RegexOptions.Compiled | RegexOptions.Multiline);
static void Main(string[] args)
{
string newString = matcher.Replace(ExampleFileContent, new MatchEvaluator(evaluator));
}
static string evaluator(Match m)
{
return String.Format("$NETS\r\n'{0}'; {1}\r\n'{2}'; {3}\r\n$END\r\n",
m.Groups["entrytitle"].Value,
m.Groups["entryrest"].Value,
m.Groups["entrytitle2"].Value,
m.Groups["entryrest2"].Value);
}
Hope this helps,
I recently discussed editors with a co-worker. He uses one of the less popular editors and I use another (I won't say which ones since it's not relevant and I want to avoid an editor flame war). I was saying that I didn't like his editor as much because it doesn't let you do find/replace with regular expressions.
He said he's never wanted to do that, which was surprising since it's something I find myself doing all the time. However, off the top of my head I wasn't able to come up with more than one or two examples. Can anyone here offer some examples of times when they've found regex find/replace useful in their editor? Here's what I've been able to come up with since then as examples of things that I've actually had to do:
Strip the beginning of a line off of every line in a file that looks like:
Line 25634 :
Line 632157 :
Taking a few dozen files with a standard header which is slightly different for each file and stripping the first 19 lines from all of them all at once.
Piping the result of a MySQL select statement into a text file, then removing all of the formatting junk and reformatting it as a Python dictionary for use in a simple script.
In a CSV file with no escaped commas, replace the first character of the 8th column of each row with a capital A.
Given a bunch of GDB stack traces with lines like
#3 0x080a6d61 in _mvl_set_req_done (req=0x82624a4, result=27158) at ../../mvl/src/mvl_serv.c:850
strip out everything from each line except the function names.
Does anyone else have any real-life examples? The next time this comes up, I'd like to be more prepared to list good examples of why this feature is useful.
Just last week, I used regex find/replace to convert a CSV file to an XML file.
Simple enough to do really, just chop up each field (luckily it didn't have any escaped commas) and push it back out with the appropriate tags in place of the commas.
Regex make it easy to replace whole words using word boundaries.
(\b\w+\b)
So you can replace unwanted words in your file without disturbing words like Scunthorpe
Yesterday I took a create table statement I made for an Oracle table and converted the fields to setString() method calls using JDBC and PreparedStatements. The table's field names were mapped to my class properties, so regex search and replace was the perfect fit.
Create Table text:
...
field_1 VARCHAR2(100) NULL,
field_2 VARCHAR2(10) NULL,
field_3 NUMBER(8) NULL,
field_4 VARCHAR2(100) NULL,
....
My Regex Search:
/([a-z_])+ .*?,?/
My Replacement:
pstmt.setString(1, \1);
The result:
...
pstmt.setString(1, field_1);
pstmt.setString(1, field_2);
pstmt.setString(1, field_3);
pstmt.setString(1, field_4);
....
I then went through and manually set the position int for each call and changed the method to setInt() (and others) where necessary, but that worked handy for me. I actually used it three or four times for similar field to method call conversions.
I like to use regexps to reformat lists of items like this:
int item1
double item2
to
public void item1(int item1){
}
public void item2(double item2){
}
This can be a big time saver.
I use it all the time when someone sends me a list of patient visit numbers in a column (say 100-200) and I need them in a '0000000444','000000004445' format. works wonders for me!
I also use it to pull out email addresses in an email. I send out group emails often and all the bounced returns come back in one email. So, I regex to pull them all out and then drop them into a string var to remove from the database.
I even wrote a little dialog prog to apply regex to my clipboard. It grabs the contents applies the regex and then loads it back into the clipboard.
One thing I use it for in web development all the time is stripping some text of its HTML tags. This might need to be done to sanitize user input for security, or for displaying a preview of a news article. For example, if you have an article with lots of HTML tags for formatting, you can't just do LEFT(article_text,100) + '...' (plus a "read more" link) and render that on a page at the risk of breaking the page by splitting apart an HTML tag.
Also, I've had to strip img tags in database records that link to images that no longer exist. And let's not forget web form validation. If you want to make a user has entered a correct email address (syntactically speaking) into a web form this is about the only way of checking it thoroughly.
I've just pasted a long character sequence into a string literal, and now I want to break it up into a concatenation of shorter string literals so it doesn't wrap. I also want it to be readable, so I want to break only after spaces. I select the whole string (minus the quotation marks) and do an in-selection-only replace-all with this regex:
/.{20,60} /
...and this replacement:
/$0"¶ + "/
...where the pilcrow is an actual newline, and the number of spaces varies from one incident to the next. Result:
String s = "I recently discussed editors with a co-worker. He uses one "
+ "of the less popular editors and I use another (I won't say "
+ "which ones since it's not relevant and I want to avoid an "
+ "editor flame war). I was saying that I didn't like his "
+ "editor as much because it doesn't let you do find/replace "
+ "with regular expressions.";
The first thing I do with any editor is try to figure out it's Regex oddities. I use it all the time. Nothing really crazy, but it's handy when you've got to copy/paste stuff between different types of text - SQL <-> PHP is the one I do most often - and you don't want to fart around making the same change 500 times.
Regex is very handy any time I am trying to replace a value that spans multiple lines. Or when I want to replace a value with something that contains a line break.
I also like that you can match things in a regular expression and not replace the full match using the $# syntax to output the portion of the match you want to maintain.
I agree with you on points 3, 4, and 5 but not necessarily points 1 and 2.
In some cases 1 and 2 are easier to achieve using a anonymous keyboard macro.
By this I mean doing the following:
Position the cursor on the first line
Start a keyboard macro recording
Modify the first line
Position the cursor on the next line
Stop record.
Now all that is needed to modify the next line is to repeat the macro.
I could live with out support for regex but could not live without anonymous keyboard macros.