Questions tagged [regular-expressions]

is for patterns specifying search or replace strings. Also known as `regex` or `regexp`, the patterns describe strings to match when searching or replacing. Emacs provides extensive support for `regex` patterns in many commands. Emacs also provides an interactive expression builder for such patterns.

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2
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0answers
57 views

org-table: hide grid lines

I like how org-mode allows me to quickly create and edit tables. However, I do not like the table's appearance and I would like to modify it. Customizing the face only lets me change foreground and ...
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2answers
225 views

How to get the position after matching and replacing a regular expression (replace-match)?

SHORT How to substitute (nicely) a regular expression by a string in pure elisp, like the unix command sed. LONG I'm using the function replace-match after string-match, but I can't get the right ...
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1answer
551 views

How to regex match words? (in multiple languages)

I have a simple regex search which matches [A-Za-z], however I would like it to match other characters which would be used in dictionary words for non-english languages. e.g. ü, Ø, ɵ 人参, while ...
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2answers
136 views

Check whether a string is a date in a specific format, e.g. “%Y-%m-%d”

I have a string and would like to check whether it contains a date in a given date format, e.g. "%Y-%m-%d", with format as for format-time-string. This is for a package and users can configure the ...
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1answer
64 views

How to set a variable that matches different type of strings?

I have these strings: First Type: arXiv:1234.56789 arXiv:1234.56789v1 Second type: hep-th/123456789 hep-th.AB/12345689 hep-th/123456789v1 hep-th.AB/12345689 Belong to the second type even strings ...
3
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1answer
60 views

can emacs memoize regexps?

This is really a question about implementation rather than anything a user of GNU Emacs would be interested in. Emacs regexps are represented as strings. There is a nice rx DSL for constructing ...
4
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1answer
204 views

Non-greedy regex group

This is related to my previous question over here. (replace-regexp "\\(\\[\\[\\)\\(zotero:.+\\]\\)\\(\\[.+,[《〈][^《〈]+[》〉]\\)?.+。\\(\\]\\]\\)" "\\1cite-\\2\\3\\4,頁") I'd like to use the above code ...
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2answers
93 views

How to match first character in line after asteriks and space using regex?

For example i have lines: * test1 ** another tests * some other line I would like to match t in first line, a in second, s in third.
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1answer
100 views

what does the vertical bar “|” mean in sentence-end?

Reference to 12.1 The Regular Expression for sentence-end of Elisp introduction It illustrate alternatives of sentence-end as \\($\\| \\| \\) ^ ^^ TAB SPC and explains: Two ...
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66 views

Why is Emacs hanging or seeming like it isin an infinite loop?

In my current Emacs major-mode for Tecplot macro development, I have a few functions defined: (defconst tecplot-macro-mode-syntax-table (let ((table (make-syntax-table))) ;; ' is a string ...
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1answer
56 views

How do I build a regexp that enables Emacs to set all words to the left of an equal sign a specific font-lock-*-face?

Following some help provided by Tobias, I am trying to assign a font-lock-keyword-face to all text (:alpha:) to the left of an equal sign (=) in a new Tecplot major mode. I read through the regexp ...
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1answer
630 views

Regexp for the inverse of a match

Given a regexp A, how do I derive the inverse regexp B such that given any text exactly one of the two regexes will match it. For example in the below example: (rx (or (group ---regexpA---) ; a ...
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1answer
648 views

How to regexp-search for a word surrounded by spaces

I'm looking at this One use of regexp-quote is to combine an exact string match with context described as a regular expression. For example, this searches for the string that is the value of ...
2
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1answer
63 views

Query replace regexp with a distant match?

I have a single transcript file for a set of course lectures I am watching. After doing some formatting on the file. I have it broken up into sets of lessons where the main heading is the lesson title ...
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1answer
65 views

Limit font-lock highliting to first N chars of line

I write regex for font-lock and I know that the date should appear in first 40 chars of line. How can I limit search beyond some limit? I tried to add ^.\\{0,40\\}XXX but Emacs regex . is greedy ...
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1answer
124 views

Regular expression to ignore a domain in address completion

I read the manual on address autocompletion: mu4e-compose-complete-ignore-address-regexp — a regular expression to filter out other ‘junk’ e-mail addresses; defaults to "no-?reply". I am looking ...
0
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1answer
258 views

Counting number of matches in number of lines for regex search

I have functions that run re-search-forward and gather its output into a buffer. (defun my-search (pattern) "Uses `re-search-forward` to return matching lines." (let ((src) (rslt)) (...
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1answer
174 views

re-search-forward Regex behavior for OR boolean

We usually use \| to depict OR in Regex. Using a\|b as input to Regexp I-search and Occur both gave the desired result. But re-search-forward seems unable to recognize this notation. abcdcba (re-...
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2answers
248 views

Regexp for matching quoted strings that may have control characters in them

I am trying to use a regexp to match strings, e.g. a pattern that matches these kinds of quoted strings: "test" or 'test' or 'test with "quote"' or "test with 'quote'" This pattern matches all those,...
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1answer
45 views

How to find the next match with re-builder?

I built a complicated regular expression with re-builder and see that it works with the matches I want. How can I find all the matches, as I would with C-s in isearch-forward?
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73 views

Is point in a regexp?

I am looking for something like thing-at-point for a regexp. For example, I want a function called regexp-at-point-p that will return the matched text if the text around the point matches the regexp ...
2
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1answer
104 views

Can Dired query replace use regular expression to rename a group of files?

So I have long list of files that I'm trying to use regex to rename but, it looks like it does not take standard regular expressions. I’m sure I’m just doing this incorrectly. After entering dired ...
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2answers
247 views

How to match the nondirectory part of a filename with a regular expression?

Whats the correct way to match a filename from a full path using string-match-p. Say I want to check if the file is a git commit message COMMIT_EDITMSG or svn-commit.tmp or svn-commit.3.tmp to pass ...
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561 views

Regular expression for finding 'href' attribute value of <a> HTML element

I need a regex pattern for finding web page links in HTML. For example <a href="https://www.google.com/search?q=elisp+regex+lookaround" ....></a> I can use (?<=href=\").+?(?=\") | (?&...
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2answers
1k views

Non-greedy regex not working

I can't seem to get the non-greedy regex to work. Sample String: ABCD,E《F》、《GH》、《XYIJ》、《KL》、《MN》。 Regex Code: 《.+?IJ》 Search Result: Because .+? is a non-greedy input, I was expecting the ...
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1answer
71 views

Regex search contains font-lock strings

I am searching in a buffer for a regular expression by this snippet: (setq jb-revision-version "\\([[:digit:]]+\\.?\\)") (setq jb-revision-string "\\(\\(Revision\\|Id\\): +\\)") (progn (save-...
4
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1answer
59 views

How to highlight digit groups of 3 in numerals?

I find it very useful to visually distinguish every 3 digit group of numbers in source code so that I can read it. For example something if I see 1000000 it is fairly easy to see that this is 1M ...
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104 views

Regex search and edit text simultaneously with multiple cursors

I'd like to search for a pattern with regex and simultaneously cut or edit all instances of that pattern. Is there a ready-made function for this? Atom, for example, has one such package - by ...
0
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1answer
58 views

Accessing regular expression groups outside a buffer

The code from here accesses groups of a regular expression match in a buffer in interactive mode: (let ((re (concat "\\([ \t]*" org-clock-string " *\\)" "\\([[<][^]>]+[]&...
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1answer
112 views

Regular expression gives different results as variable and as literal

In the Emacs *scratch* buffer, I get different results when I use the same regular expression as a variable compared to a literal: (setq splitter-string "9:20") "9:20" (string-match "[0-9]?[0-9]:[0-...
2
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1answer
106 views

How to count regexp in a string and use that number in replacement?

In my LaTeX code I want to replace these strings: \left.\left.\left. \left.\left. \left. with: \left.\left.\left. \mycommand{3} \left.\left. \mycommand{2} \left. \mycommand{1} where the argument ...
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0answers
68 views

Why correct regexp not work in query-replace-regexp?

I want to add 400 in every line where has text "finished". Here text and regexp: as you can see the regexp is correct "finished":\s-*[0-9]+ Nice. Now I use this regexp in query-replace-regexp ...
4
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1answer
255 views

Is [:space:] same as \s-?

Emacs 26.1 In regexp help https://www.emacswiki.org/emacs/RegularExpression has the next regexp: [:space:] a whitespace character Is this a same as: [ \t\r\n\v\f] and same as \s- ?
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1answer
509 views

Replace full-width numerals with half-width numerals

I'd like to convert numerals from half-width to full-width characters with a simple regex search and replace as follows: replace-regexp-in-string regexp rep string &optional fixedcase literal ...
0
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1answer
26 views

How to include lines in a regular expression search which might not be present?

I'm using a regular expression search which is working as expected. This searches for unified diff file entries and works as expected. (re-search-forward (concat ;; Prefix '+++ '. "^" "...
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0answers
21 views

Matches from re-builder different from re-search-forward and search-forward-regexp due to double backslash [duplicate]

Following Org mode refiling gobbles a newline and absorbs the next heading where Org mode refiling has gobbled some of the next heading, I want to search for those gobbled headings where the stars are ...
0
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1answer
28 views

Replace lines with ( with :( by regex-replace

I have such a snippets: Exercise 2.32. We can represent a set as a list of distinct elements, and we can represent the set of all subsets of the set as a list of lists. For example, if the set is (1 ...
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1answer
33 views

Adding `**` to head of lines with numbers in the beginning

I have the following contexts: 4. Pattern-Matching Conditional: How to use pcase and friends. 5. Iteration: while loops. 6. Generators: Generic sequences and coroutines. and intent add ** to the ...
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1answer
83 views

Fold all regexp matches

I'm working on email templates using web-mode, which – alas – requires inline styling galore… many of my opening tags won't fit on a single line even on a 4K-Display due to the massive amount of ...
3
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1answer
251 views

Simplest Pattern for matching Identifiers in complex Regular Expressions?

I frequently need a regular expression, that approximately matches identifiers in a given environment. Ignoring the "must not start with a number" requirement, this would mean e.g. [[:alnum:]_]+ ...
2
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1answer
112 views

Match any character in a regexp (e.g. `string-match`)

In perl when matching multi-line strings you can add the s modifier /.../s that will change the semantics of . to match also newline. Is there something similar for string-match? Or is there a ...
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2answers
88 views

How to write regex to change the go keywords color?

I want to change the color which in package import go defer in go-mode ,need a regex..these code only change the pacakge word color (defface my-font-lock-gokeyword-face `((t (:foreground "#...
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1answer
750 views

How to understand paragraph-start variable regex

Problem When i evaluate the paragraph-start variable in the major mode lisp-mode, it has the following value "^L\\|[ ]*$" In emacs the ^L is displayed in red color so I'm not sure if there is ...
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0answers
39 views

Is there is an existing parser for `.gitignore` files?

Is there is an existing parser for .gitignore files? Maybe there is some Elisp package that includes something like this? Ideally, I would like to be able to read a .gitignore file in a given ...
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0answers
34 views

Simple regexp inside emacs keyboard macro

Newbie question: I'm trying to record a keyboard macro with a simple regexp inside (search-backward-regexp ^[0-9]). This works well when recording the macro, but as soon as I try to execute it, the ...
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0answers
50 views

How can I split LaTeX inline math from preceeding or following sticked words?

I have this LaTeX code: Lorem $math$ ipsum $math$dolor sit consecteruer adipscing elit, sed do eiusmod tempor incidunt ut labore et dolore magna aliqua. $math$Ut $math$ enim ad minim veniam$math$, ...
2
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1answer
140 views

elisp regular expression build problem

I have the following line : mod_name func_name /users/username/workspace/path_name/file.c 283 I wanted to capture the 3rd and 4th entry in this line, I am able to do that using regular expressions ...
1
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1answer
40 views

Basic quote regex for font-locking?

I have my own font locking that highlights quotes in comments eg. /* Some comment 'this is quoted' * more 'text in an escaped \` quote'. * Plurals such as Moe's or Joe's should work too. */ ...
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1answer
93 views

How to count matches of all buffers?

I am looking for a way to count regexp matches across all buffers. count-matches can count in current buffer. How to count across all buffers?
5
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1answer
310 views

Folding custom regular expressions in emacs?

Consider a pattern/regular expression I will call reg which matches multiple times in an emacs buffer. I want emacs to recognize all matches for reg and replace (temporarily, like folding) each ...

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