Im working on a crude console based text editor in C++ kind of like nano. I've already figured out a basic way of inputting multiple lines of text and writing it to a file correctly (input ends when they enter a code: //end). However, at the moment the user is unable to move upwards (using arrow keys) and edit lines that they have entered. For some additional information I'm doing this with a getline() loop, writing files with ofstream, and am storing the users text in a string vector with each element being an entered line. How might I implement the ability to work with a body of text in such a way?
For advanced use, you need access to the console API.
For a simpler version, look at the primitive visual editors.
Editing a line consists of moving to the line, printing out the content, and then letting them insert or delete characters on that line.
Look at sed or ed or even vi.
I am struggling hard on this one.
I need to parse a portion of rtf1 document to rtf2 document. Here is the basic approach:
1) Open rtf1 in notepad and find the unique start point(line) and end point(line).
2) Copy portion from point start point to end point and insert it in rtf2 document.
I know how to insert the portion in rtf2 document but couldn't figure out how to extract the portion. The portion that needs to be copied is lengthy so I have to find a way to input start point and end point so I can use those two reference points to extract anything that falls in between.
Thank you in advance for your valuable input.
Zora
Find startPoint.*?endPoint using Regular expression -search mode with . matches newline enabled. Then copy selected text to clipoard.
.*? basically means "match any character until end point is found".
Remember to escape any special characters when defining the start- and endpoints.
|.......before.......|....portion-to-copy....|.....after..........|
If I need to perform such a task, I use simple method (in Notepad, Notepad++) - you can try it, too:
With text cursor at start point, you can press Ctrl+Shift+Home and then Delete. This deletes all content before your portion. (Do not save the file.)
With text cursor at end point, you can press Ctrl+Shift+End and then Delete. This deletes all content after your portion. (Do not save the file.)
Now you have only your portion. Press Ctrl+A (select all), then Ctrl+C to copy it into the clipboard. In SAS: Press Ctrl+Home, then press Ctrl+Shift+End. Then press Ctrl+C.
Paste your portion where you need.
Close your original document (used in steps 1-3) without saving.
I'm writing a payroll program in c++ and need to be able to read lines in a file, do calculations, and then overwrite the read lines in the file. IS there a function/way i can simply overwrite specific lines, insert new lines, add onto the end of an existing file?
There are no C++ functionality to "insert" or "remove" text in a text-file. The only way to do that is to read the existing text in, and write out the modified text.
If the new text fits in the same space as the old one, all you need to do is to overwrite the existing text - and of course, you can always add extra spaces before/after a comma in a .CSV file, without it becoming part of the "field". But if the new data is longer, it definitely won't work to "overwrite in place".
Adding to the end is relatively easy by using the ios_base::ate modifier. But inserting in middle still involves basically reading until you find the relevant place, and then, if the new text is longer, you have to read all the following lines before you can write the new one(s) out.
I have a huge size word document (32MB). All I want to do is to find and replace the following characters with something (say space or nothing, that is remove them) but only in all the headings (h1 to h9 or every heading level being used) and not anywhere else:
,-_;~%&*()?/.
Can anyone help? I want to do it using a macro. I know the manual way using the Find dialog but it is too cumbersome because of the huge size of the document. Thank you for help.
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"ΒΆ + "/
...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.