extract specific string from a file using c++ - c++

file content:
/function name: input\n\t\tworking: inputs details\n\t\t/
/*fuction name: datawrite\n\t\tworking: write the data into the file
*/
/function name: dataread\n\tworking: read the data in the file for
display/
/*funtion name: accsummary\n\t\tworking: display the content of the
file of specific person */
I want to extract only the "function names" and the "workings" from the file and store them into the array of string. "using c++"
that is, if i have declared an array of string function[10] then this should store "input,datawrite,dataread,accsummary" similarly from "working"

This sounds like a task for regular expression. In C++ there is support for regex especially regex_match.
I guess, this should get you started. But be warned, what you are trying to accomplish will not be solved by simple regex.
Your matching string might look something like this
/\/function name: ([^\\]*).*/
This will look for string "function name: " followed by any character other than \ . and then any character up to the end of the line. The second part will be remembered and can be accessed by regex_match.
Try it in online regex tester and modify it based on your specific needs. Just note that it takes regex without leading and ending /.
Oh, I noticed that you asked also for extracting workings, while my example extracts only function names. But you will get there when you get the concept.

You need to take a look at the std::stringstream class:
http://www.cplusplus.com/reference/sstream/stringstream/
Then you need to look at the substr method in std::string:
http://www.cplusplus.com/reference/string/string/substr/

Related

How can I create a Regex that matches and transforms a period delimited path?

I am using den4b Renamer to rename a lot of files that follow a specific pattern. The program allows me to use RegEx: (https://www.den4b.com/wiki/ReNamer:Regular_Expressions)
I am stuck trying to conjure up an expression for a specific pattern.
My current RegEx:
Expression: ^(com\.)(([\w\s]*\.){0,4})([\w\s]*)$
Replace: \L$1\L$2\u$4
Note: \L and \u transform the sub-expression to upper and lower case as defined in the table below:
Here are a few example strings so you can get an idea of the input:
Android File Transfer.svg
Angular Console.svg
Au.Edu.Uq.Esys.Escript.svg
Avidemux.svg
Blackmagic Fusion8.svg
Broken Sword.svg
Browser360 Beta.svg
Btsync GUI.svg
Buttercup Desktop.svg
Calc.svg
Calibre EBook Edit.svg
Calibre Viewer.svg
Call Of Duty.svg
com.GitHub.Plugarut.Pwned Checker.svg
com.GitHub.Plugarut.Wingpanel Monitor.svg
com.GitHub.Rickybas.Date Countdown.svg
com.GitHub.Spheras.Desktopfolder.svg
com.GitHub.Themix Project.Oomox.svg
com.GitHub.Unrud.Remote Touchpad.svg
com.GitHub.Unrud.Video Downloader.svg
com.GitHub.Weclaw1.Image Roll.svg
com.GitHub.Zelikos.Rannum.svg
com.Gitlab.Miridyan.Mt.svg
com.Inventwithpython.Flippy.svg
com.Neatdecisions.Detwinner.svg
com.Rafaelmardojai.Share Preview.svg
com.Rafaelmardojai.Webfont Kit Generator.svg
Distributor Logo Antix.svg
Distributor Logo Archlabs.svg
Distributor Logo Dragonflybsd.svg
DOSBox.svg
Drawio.svg
Drweb GUI.svg
For this question I am focused on the strings that begin with com.xxx.xxx.
Since I can't only target those names in Renamer, the expression has to "play nice" with the other input file names and correctly leave them alone. That's why I've prefixed my expression with ^(com\.)
What I want:
Transform the entire string to lower case except for the last period separated part of the string.
Strip white space from the entire string.
For instance:
Original: com.GitHub.Alcadica.Develop.svg
After my Regex: com.github.alcadica.Develop.svg
What I want: com.github.alcadica.Develop.svg
This specific file is correctly renamed. What I'm having trouble with are names that have spaces in any part of the string. I can't figure out how to strip whitespace:
Original: com.Belmoussaoui.Read it Later.svg
After my Regex: com.belmoussaoui.Read it Later.svg
What I want: com.belmoussaoui.ReaditLater.svg
Here is a hypothetical example because I couldn't find a file with more than four parts. I want my pattern to be robust enough to handle this:
Original: com.Shatteredpixel.Another Level.Next.Pixel Dungeon.svg
After my Regex: com.shatteredpixel.another level.next.Pixel Dungeon.svg
What I want: com.shatteredpixel.anotherlevel.next.PixelDungeon.svg
Note that since I'm not using any kind of programming language, I don't have access to common string operations like trim, etc. I can, however, stack expressions. But this would create more overhead and since I am renaming thousands of files at a time I'd ideally like to keep it to one find/replace expression.
Any help would be greatly appreciated. Please let me know if I can provide any more information to make this more clear.
Edit:
I got it to work with the following rules:
Really inefficient, but it works. (Thanks to Jeremy in the comments for the idea)

Regex-Match while ignoring a char from Searchword

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>')

Scanning a language with non-delimited strings with nested tokens

I want to create a lexer/parser for a language that has non-delimited strings.
Which part of the language is a string is defined by the command preceding it.
For example it has statements that look like this:
pause 5
alert Hello world[CRLF] this contains 'pause' once (1)
Alert in this instance can end with any string, including keywords and numbers.
Further complicating things, the text can contain tags like [CRLF] that I want to separate too.
Ideally I'd want this to be broken up into:
[PAUSE][INT 5]
[ALERT][STR "Hello world"][CRLF][STR " this contains 'pause' once (1)"]
I'm currently using flex but from what I've gathered this kind of thing isn't possible with flex.
How can I achieve what I want here?
(Since one of your tags is "regex", I'll suggest a non-flex approach.)
From the example, it seems like you could just:
match each line against ^(\w+) (.+) to obtain command and arguments-text, and then
get individual arguments by splitting the arguments-text on (\[\w+\]) (assuming your regex library's split function can return both the splitter-strings and the split-strings).
It's possible your actual situation is more complex and something like flex makes more sense, but I'm not really seeing it so far.

Parse a string for open and close tags

Let's say I have the following strings:
"This [color=RGB]is[\color] a string."
"This [color=RGB][bold]is[\bold][\color] another string."
What I'm looking for is a good way to parse the string in order to extract the tag information and then reconstruct the original string without tags.
The tag informations will be used during text rendering.
Obviously I can achieve the goal by working directly with strings (find/substr/replace and so on), but I'm asking if there is another way cleaner, for example using regular expression.
Note:
There are very few tags I need, but there is the possibility to nest them (only of different type).
Can't use Boost.
There's a very simple answer that might work, depending on the complexity of your strings. (And me understanding you correctly, i.e. you just want to get the cleaned up strings, not actually extract the tags.) Just remove all tags. Replace
\[.*?]
with nothing. Example here
Now, if your string should be able to contain tag-like objects this might not work.
Regards

Reading a text config file: using regex to parse

Looking for a way to read the following config file sample using a multi line regex matcher. I could just read in the file by line, but I want to get decent with the specifics of flexible regular expression matching.
So the config file is filled with blocks of code as follows:
blockName BLOCK
IDENTIFIER value
IDENTIFIER value
IDENTIFIER
"string literal value that
could span multiple lines"
The number of identifiers could be from 1..infinity. IDENTIFIER could be NAME, DESCRIPTION, TYPE, or the like.
I have never worked with multi line regular expressions before. I'm not very familiar with the process. I essentially want to use a findAll function using this regular expression to put all of the parsed block data into a data structure for processing.
EDIT: clarification: I'm only looking to read this file once. I do not care about efficiency or elegance. I want to read the information into a data structure and then spit it out in a different format. It is a large file (3000 lines) and I don't want to do this by hand.
I don't think regex is the best tool for this.
Try this, which should work in perl regular expressions:
([\w\d]*)\s+BLOCK\s*\n(\s*(NAME|DESCRIPTION|TYPE|...)\s*([\w\d]*|"(.*)")\s*\n)+
I verified it at REGex TESTER using the following test text:
blockName BLOCK
NAME value
NAME value
DESCRIPTION
"string literal value that
could span multiple lines"
otherName BLOCK
NAME value
TYPE value
DESCRIPTION
"string literal value that
could span multiple lines"
It will only find the last block/identifier if the file ends in a newline