Regex (or regexp) is known as regular expression matching of patterns, strings or characters in, for example, a large text file. Questions should be tagged as such whatever the programming language involved and the tag can also apply to command-line or graphical programs that have regex plugins or ...

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2
votes
2answers
17 views

How can I edit a range of text between 2 symbols? awk, sed, regex

Using the "*" symbol, (doesn't have to be that one, any special character will do in order to indicate), how can I edit the text from this: *berry straw rasp blue boysen * blahblah blahblah blahblah ...
2
votes
1answer
119 views

How do I use the “^” and “$” symbols with regular expressions in a bash script?

How do I use the "^" and "$" symbols with regular expressions in a bash script? Please give me an example using both symbols.
4
votes
3answers
90 views

Reverse sed's/regexes' pattern-matching priority order

Consider this command: echo "string.with.dots" | sed 's/\(.*\)\.\(.*\)/\1\n\2/' (Matches into a first capturing group any character until the last . and into a second capturing group any character ...
1
vote
4answers
232 views

What is a practical way to list every character used in a file (Bash) (Regex)

How can I turn this: Johnny's penguin, (Tuxie), likes the following foods: French fries, and beef. To this: abcdefghiklnoprstuwFJT',():. (These are the total characters used in the input) ...
0
votes
1answer
53 views

How can I split a line in 2 by words/characters? (Bash) (Regex)

I would like to convert: Hello Hello Hi Hello Hello Hi Hi Hi Hi Hello To: Hello Hello Hi Hello Hello Hi Hi Hi Hi Hello I want to split a single line in 2, by having them have the closest amount ...
0
votes
3answers
57 views

Batch rename, add extra “.” character at position 3 in filename, recursively

I've been struggling to make this work but I am not very good with regex. This is what I tried to do and it didn't work (after 50 minutes, still going on with no visible change): while IFS= read -r ...
1
vote
1answer
27 views

Command-line perl regex replacement: replacement string contains utf8

Say you have a file named test.txt with the following lines: ಕದಂ.ಬ कदम्ब. Then, suppose you want to replace each dot following a devanagarI unicode character (ie in कदम्ब) with a ।. Then, you might ...
1
vote
1answer
49 views

Find and replace regular expression (matching unicode character class Devanagari) in multiple files

Say you have a file named test.txt with the following lines: ಕದಂಬ कदम्ब Then, suppose you want to replace each devanagarI unicode character (ie in कदम्ब) with a D. Then, you might think that the ...
2
votes
3answers
83 views

How do I extract a single attribute from an XML file?

I'm not really familiar with regex, sed, etc. and a bit lazy to figure it out right this moment, so how do I extract this line: <yweather:astronomy sunrise="6:50 am" sunset="7:06 pm"/> Let me ...
3
votes
3answers
61 views

Move pattern to beginning of line

I am trying to reformat a log file such that date and time appear at the beginning of the line. My logs look like this: blah, blah, blah, Friday, Mar 13,2015 16:59:42 yadi, yadi, yada, Friday, Mar ...
2
votes
3answers
119 views

Remove all text before last space in text file from CLI

I want to remove everything before the last space in a text file from the CLI Example text: 2015-03-02 21:34:15 20480 dump-2015-03-02-21-34.tar The string that should remain is ...
0
votes
1answer
49 views

Excluding hidden files in locate

We have a Ubuntu NAS sharing SMB and Netatalk with some Macs and I often use locate to find my files. Unfortunately since installing Netatalk it has written tons of .AppleDouble cache files to share ...
0
votes
2answers
81 views

unable to install apache2 on precise

Below is the error while running the command: root@mycompanyname:~# apt-get install apache2* Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to ...
-1
votes
2answers
47 views

faced problem in regex

i am having a text file which contain some queries like below. leptop pencil group leptop book gruop buk grop laftop pensil laptop pancil laptop bag bok from this i just want query which start with ...
0
votes
1answer
28 views

Syntax for regex in IF statment

I'm trying to come up with the syntax for a regex in an IF statement, but I'm not quickly having success... Can anyone lend a quick hand please? if [[ "$path/$file" =~ .{txt,doc,docx,xlsx,rtf} ]]; ...
1
vote
1answer
43 views

Color the regular expression in same file

I have a big file and need to look over certain patterns. and also look for another patterns based on first pattern and thus this requires to color the lines which matches the search in the same file. ...
1
vote
3answers
115 views

One liner ffmpeg (or other) to get only resolution?

I'm not really well versed in the command line so hopefully this isn't too stupid of a question. If I run: ffmpeg -i videofile.avi I get an output such as this: ffmpeg version ...
1
vote
1answer
165 views

Why do these regular expressions in grep behave strangely?

I wanted to play a bit with a grep command using regular expressions and find out that they behave differently from what I expected. For example, for a file temp with the following content helloworld ...
-4
votes
3answers
696 views

find all headers file begin with vowels in /usr/include

I need to find all headers from /usr/include that begin with vowels (a,e,i,o,u) Example: acpi.h aclinux.h ah.h ... I don't know how to do it , I tried something with grep but I didn't make it ...
2
votes
3answers
69 views

Regex PDF search?

I am an electronics engineer and I regularly view PDF schematics. Often I encounter the scenario where I would like to search the schematic for a component, e.g. "R1" The problem is that searching ...
0
votes
1answer
20 views

Using grep with regex

I have a regex which works fine for me. I checked it on following site: https://www.regex101.com/ (?<=.log:)[^;]* Unfortunately it doesn't work anymore when I try to use it with grep. I try to ...
0
votes
1answer
36 views

Grep for specfic number format

I have a Unix script, which within has release numbers which are like this (2.19.0.32) Look like IP's but are not as some are like this 2.23.0.06.DBP. I've tried variations of this but comes back ...
4
votes
4answers
964 views

How to find all patterns between two characters?

I'm trying to find all patterns between a pair of double quotes. Let say I have a file with contents look like as following: first matched is "One". the second is here"Two " and here are in second ...
0
votes
0answers
35 views

header_checks in Postfix

I attempted to write a regex for header_checks to filter out To: header, but it is not working. The assumption is: if a header To: does not contain local domain names it will reject the message. ...
4
votes
3answers
364 views

Replace text inside quotes in vim

I have a large sql file and I would like to rename the table name from `feedback` to `comments` but I don't want to replace the word feedback in case any row has that text so I was trying to select it ...
1
vote
4answers
324 views

extract text from a file using terminal?

I want to process the body of text and extract an integer from a specific position in the text, but I'm not sure how to describe that 'particular position'. Regular expressions really confuse me. I ...
1
vote
2answers
337 views

Exclude directories from inotifywait

Doing an inotifywait to watch a directory, and trying to exclude all subdirectories from being watched while not excluding the files. inotifywait -r -q --exclude <pattern> dir/ What to put in ...
2
votes
1answer
71 views

Vi syntax highlighting for words followed by a parenthesis

I want to change the color of a keyword that is followed by a left parenthesis in a .R file. For instance, when I type length(), I want the word length to be highlighted (and not the parentheses), ...
2
votes
1answer
713 views

Fail2Ban Regex SSH Will not Match Auth.Log - Searched Everywhere for a Solution

Im trying to get Fail2Ban to work with the SSHD Config provided. When i run fail2ban-regex /var/log/auth.log /etc/fail2ban/filter.d/sshd.conf The Output is as follows ...
0
votes
1answer
58 views

Explain in details egrep line

Hi i found in the internet egrep line. The line founds the longest line in the text. But i dont understand specific elements. Maybe someone could explain me all line? Here it is: egrep -n "^.{$(wc -L ...
2
votes
2answers
86 views

Change text in many files

I have a C++ project, where each file has at its beginning some lines of license. Now, that my license have changed, I need to update it in each file. I don't want to do it manually, since its lots of ...
1
vote
2answers
559 views

How do I use regex to remove all punctuation and symbols? [closed]

I'm using Python 2.7 regex. I need to remove all symbols, punctuation, numbers and whitespace from strings in different languages. For example, these two strings: the following characters: ...
0
votes
1answer
89 views

How can I uninstall only one of the versions of Libre Office?

I have both versions of Libre Office installed - 4.3 and the default: dpkg --get-selections | grep -v deinstall | grep libreoffice shows libreoffice-avmedia-backend-gstreamer libreoffice-base-core ...
5
votes
1answer
192 views

How to rename the set of files with pattern

I have files which has name as following: P50_FR_8_q2_scrolls.csv Here the value 50 and 8 needs renaming & The results should be something like: P21_FR_3_q2_scrolls.csv I tired few ...
1
vote
1answer
472 views

Undo apt-get remove --purge

I wanted a fresh install of Python and ran sudo apt-get remove --purge python. Apparently it has killed almost everything I had installed in my system. Looking at the history.log I guess I could ...
1
vote
1answer
115 views

Ubuntu rename command regex not working

I'm trying to use the rename command to rename a bunch of images in a folder. I have this list of images, image.php?x=10 image.php?x=25 image.php?x=50 image.php?x=75 I'm trying to rename them to ...
0
votes
3answers
63 views

Batch Rename Using Regex but Mainaining Some Substring

I made a lot of research before I put this question. I found a different links to do batch rename using regex like this and other similars: *Pattern based, batch file rename in terminal My problem ...
3
votes
1answer
138 views

What happens if we add a dot at the end of sudo `apt-get autoremove`

sudo apt-get autoremove . OUTPUT: WARNING: The following essential packages will be removed. This should NOT be done unless you know exactly what you are doing! apt libapt-pkg4.12 (due to apt) libc6 ...
4
votes
6answers
328 views

Bash script programming: how to match pattern in string?

How I can get this whole value 7I45432ZX from below lines: PW*3434*453*256*PE*UB PO*00*NE*7I4543 2ZX**20140617 PW*3434*453*256*PE*UB PO*00*NE*7I4543 2ZX**20140617 This is the code I tried: grep ...
2
votes
2answers
146 views

Regular expression that matches all multiple seperate expressions

It's admission time in India and I am trying my best to get the best college I can for engg. I have got a pdf file which contains a table which looks like It contains about 2500+ entries and I ...
0
votes
2answers
66 views

Regular expression

I have a code that is looking for a specific pattern in my log files. Usually it begins with Association ID = (This is what I am looking for in parenthesis). Now the code I have made so far is ...
1
vote
4answers
292 views

Change directory structure from /YEAR/MONTH/DAY/ to /YEAR-MONTH-DAY

I need to change my directory structure for my photos from /YEAR/MONTH/DAY/ to /YEAR-MONTH-DAY I know this can sort of be done with exiftool, but it will only work on files containing EXIF-tags, and ...
1
vote
2answers
79 views

how can i find all files that contain embedded crc32's

how can I find all files that contain embedded crc32's e.g. Mydocument190_[F285E17D].pdf using the find command to clarify the crc32's are always within brackets [F285E17D] and the file names may ...
0
votes
0answers
355 views

How can I use C++11's <regex> on Ubuntu?

I normally use the G++ compiler, but I don't have anything against using clang++. Reading about this, I get the idea that G++'s implementation of C++11's regex might not compile, and if it does, it ...
1
vote
2answers
213 views

Extract full link of a div element

I'm downloading episodes from a series, but I'm tired for joining in the site, copying the link and downloading it for each episode. First, I join in the site and I get the HTML code. The code is ...
1
vote
3answers
118 views

Forming IPAddresses from Text file

I have a huge text file that contains IP addresses scrambled all over but not in one unit for example. So what the@192@ heck are you doing@168@ in my house @10@.you were not @16@ supposed to be ...
4
votes
2answers
1k views

regex search works with `grep -E` but not with bash script?

I use the same regex with grep and it gives me a match but when doing it in a bash script, it return no match. Test String(part of the file testregex.txt): <a ...
1
vote
1answer
77 views

How to get sub-string for a string using pattern analysis?

I want to get sub-string of any string using pattern analysis. Example String: <string module name="Jai" fathername="S.S. Khan" phone="1234"> <address complete="startz us" /> ...
4
votes
2answers
241 views

Using Regex Breaking a text on the last digit using linux tools like sed, or awk

I have the following list that I want to break on the digit. For example: From: 103Ru 103mRh 104 1041 To: 103 Ru 103 mRh 104 1041 I would like to use Regx with sed or maybe awk in order to ...
2
votes
5answers
277 views

Help to build this expression using sed

I have a text file and I need to get rid off the entire information just before the = symbol in each line, for example: The line: File 1515 = foo.txt needs to look like this: =foo.txt So, I had ...