Replace characters within a specific string - regex

I have a text file with URLs where space is + and it needs to be %20 to work.
For example:
http://myserver/abc/this+is+my+document.doc
I want it to be:
http://myserver/abc/this%20is%20my%20document.doc
How to replace + with %20, but only when the string starts with http://myserver/abc? Don't want to replace any other +'s in the document.
Thanks in advance!

You can use the following regex:
See it in use here
(?:http://myserver/abc|\G(?!\A))[^\s+]*\K\+
Replace with %20
How the regex works?
(?:http://myserver/abc|\G(?!\A)) matches either http://myserver/abc literally, or the previously matched location (\G is previously matched location or start of the string and (?!\A) prevents \G from matching the start of the string)
[^\s+]* matches any character except whitespace and + (literally) any number of times
\K resets the match. Any previously consumed characters are excluded from the final match
\+ match this character literally

Related

How to match new-line character using regex

I'm trying to match the special characters and the breaks using a regex to cleanse the string so that I'm left with only the following string 'All release related activities' extracted from the following line:
{"Well":"\n\n\t\n\t\n\n\t\n\tAll release related activities\n\n\t"}
I've tried the regex ^{.Well":" and I'm able to match till the first colon appears. How do I match the \n characters in the string?
I am not quite sure about the prefix of "well:" So I am basically providing you with a basic regex:
^\{[^}]*?(?:\\[ntr])+([^}]+)\}
and replace by:
\1
Example
Try:
/":"(?:\\[nt])*(.*)}"$/
See Regex Demo
":" Matches ":".
(?:\\[nt])* Matches 0 or more occurrences of either \n or \t.
(.*) Matches 0 or more characters in Capture Group 1 until:
}"$ Matches }" followed by the end of the string.
The string you are looking for is in Capture Group 1.

Perl: How to substitute the content after pattern CLOSED

So I cant use $' variable
But i need to find the pattern that in a file that starts with the string “by: ” followed by any characters , then replace whatever characters comes after “by: ” with an existing string $foo
im using $^I and a while loop since i need to update multiple fields in a file.
I was thinking something along the lines of [s///]
s/(by\:[a-z]+)/$foo/i
I need help. Yes this is an assignment question but im 5 hours and ive lost many brain cells in the process
Some problems with your substitution:
You say you want to match by: (space after colon), but your regex will never match the space.
The pattern [a-z]+ means to match one or more occurrences of letters a to z. But you said you want to match "any characters". That might be zero characters, and it might contain non-letters.
You've replaced the match with $foo, but have lost by:. The entire matched string is replaced with the replacement.
No need to escape : in your pattern.
You're capturing the entire match in parentheses, but not using that anywhere.
I'm assuming you're processing the file line-by line. You want "starts with the string by: followed by any characters". This is the regex:
/^by: .*/
^ matches beginning of line. Then by: matches exactly those characters. . matches any character except for a newline, and * means zero-or more of the preceding item. So .* matches all the rest of the characters on the line.
"replace whatever characters that come after by: with an existing string $foo. I assume you mean the contents of the variable $foo and not the literal characters $foo. This is:
s/^by: .*/by: $foo/;
Since we matched by:, I repeated it in the replacement string because you want to preserve it. $foo will be interpolated in the replacement string.
Another way to write this would be:
s/^(by: ).*/$1$foo/
Here we've captured the text by: in the first set of parentheses. That text will be available in the $1 variable, so we can interpolate that into the replacement string.

Regex - replace blank spaces in line (Notepad++)

I have a document with multiple information. What I want is to build a Notepad++ Regex replace function, that finds the following lines in the document and replaces the blank spaces between the "" with an underline (_).
Example:
The line is:
&LOG Part: "NAME TEST.zip"
The result should be:
&LOG Part: "NAME_TEST.zip"
The perfect solution would be that the regex finds the &LOG Part: "NAME TEST.zip" lines and replaces the blank space with an underline.
What I have tried for now is this expression to find the text between the " ":
\"[^"]*\"
It should do it, but I don't know which expression to use to replace the blank spaces with an underline.
Anyone could help with a solution?
Thanks!
The \"[^"]*\" will only match whole substrings from " up to another closest " without matching individual spaces you want to replace.
Since Notepad++ does not support infinite width lookbehind, the only possible solution is using the \G - based regex to set the boundaries and use multiple matching (this one will replace consecutive spaces with 1 _):
(?:"|(?!^)\G)\K([^ "]*) +(?=[^"]*")
Or (if each space should be replaced with an underscore):
(?:"|(?!^)\G)\K([^ "]*) (?=[^"]*")
And replace with $1_. If you need to restrict to replacing inside &LOG Part only, just add it to the beginning:
(?:&LOG Part:\s*"|(?!^)\G)\K([^ "]*) (?=[^"]*")
A human-readable explanation of the regex:
(?:"|(?!^)\G)\K - Find a ", or, with each subsequent successful match, the end of the previous successful match position, and omit all the text in the buffer (thanks to \K)
([^ "]*) - (Group 1, accessed with$1from the replacement pattern) 0+ characters other than a space and"`
+ - one or more literal spaces (replace with \h to match all horizontal whitespace, or \s to match any whitespace)
(?=[^"]*") - check if there is a double quote ahead of the current position

Remove all characters after a certain match

I am using Notepad++ to remove some unwanted strings from the end of a pattern and this for the life of me has got me.
I have the following sets of strings:
myApp.ComboPlaceHolderLabel,
myApp.GridTitleLabel);
myApp.SummaryLabel + '</b></div>');
myApp.NoneLabel + ')') + '</label></div>';
I would like to leave just myApp.[variable] and get rid of, e.g. ,, );, + '...', etc.
Using Notepad++, I can match the strings themselves using ^myApp.[a-zA-Z0-9].*?\b (it's a bit messy, but it works for what I need).
But in reality, I need negate that regex, to match everything at the end, so I can replace it with a blank.
You don't need to go for negation. Just put your regex within capturing groups and add an extra .*$ at the last. $ matches the end of a line. All the matched characters(whole line) are replaced by the characters which are present inside the first captured group. .
matches any character, so you need to escape the dot to match a literal dot.
^(myApp\.[a-zA-Z0-9].*?\b).*$
Replacement string:
\1
DEMO
OR
Match only the following characters and then replace it with an empty string.
\b[,); +]+.*$
DEMO
I think this works equally as well:
^(myApp.\w+).*$
Replacement string:
\1
From difference between \w and \b regular expression meta characters:
\w stands for "word character", usually [A-Za-z0-9_]. Notice the inclusion of the underscore and digits.
(^.*?\.[a-zA-Z]+)(.*)$
Use this.Replace by
$1
See demo.
http://regex101.com/r/lU7jH1/5

Replace whitespaces between specific strings

I'm trying to replace whitespaces with underscores in certain parts of my html-document with Notepad++.
I can identify the area to search for the whitespaces in the following way:
-Begins with: src="video/
-Ends with: mp4
For example I might have a line like this:
<video class="play" src="video/my file name with empty spaces.mp4">
and I would like to change it to be like this:
<video class="play" src="video/my_file_name_with_empty_spaces.mp4">
Tested in N++
Search: (?:src="video|(?<!^)\G)(?:(?!mp4).)*?\K\s+
Replace: _
On the demo, see the substitutions at the bottom.
Explanation
(?:src="video|(?<!^)\G) matches the delimiter src="video, or \G the position following the previous match as long as it is not at the beginning of the string (?<!^) where \G can also match
(?:(?!mp4).) matches one character that is not followed by mp4
*? lazily matches such characters, up to...
\s a space character (our match which we replace with _)
before the space, the \K tells the engine to drop what was matched so far from the final match it returns