Regular expressions are a means of matching a pattern of characters within a string.

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Why is vi (but not cat) showing ^[[31m[^[[m^[[31m" after I use sed and output to a file I then edit? [closed]

When I use cat Variables/user-extensions.js | sed -e 's/css/XXX/' on an input file of the form storedVars["css_body"] = "css=body"; storedVars["css_main"] = "css=main"; I see output such as ...
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179 views

Sed replace portions of lines not beginning with http://

I'm getting stuck with sed.. I'm trying to prefix links in an html file with a / when they don't start with http.. I'm aware this is possibly not the best way to go about this but I'm just after a ...
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3answers
221 views

parse credentials from PHP configuration file

I'd like to write bash script to parse data from a configuration file. I searched for this but without finding something I could modify to suit my needs. Joomla! config file: public $access = ...
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3answers
386 views

sed, convert single backslash to double backslash

I have a json string, which has a potpourri of doubly escaped/singly escaped newline chars. Json parser doesn't allow its string value to have single backslash escapes. I need to uniformly make all ...
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1answer
70 views

grep -E regex syntax changed?

A lot of documentation I've read says that the following command should match lines where x appears at least 3 times in a row but no more than 4 times in a row: grep -E {x}\{3,4} E.g. ...
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336 views

logstash regex match in if condition

In logstash filtering, I have multiple tags setup based upon different error conditions and all the tags has a prefix, something like "abc:" In the output, I want to send email based upon just ...
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368 views

Match pattern \\\" using grep

I have a json string inside json. This got encoded multiple times and I ended up with many escape backlashes: \\\". The much shortened string looks like, '[{"testId" : "12345", "message": "\\\"the ...
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103 views

Pulling out a certain value from a string via regex

I've see a bunch of examples, but I just can't seem to make this work. Can grep output only specified groupings that match? for example seems like it should work, but I get either errors or no output ...
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99 views

Double square parenthese inside grep pattern

grep "^[[:space:]]*clientPort[^[:alpha:]]" zoo.cfg This is a grep pattern to extract the line that contains the port number from the configuration file. 1) Normally in a regex, I use square ...
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139 views

Use multiple commands in sed to insert text after string with special characters

I am having a little trouble trying to do a search and replace using sed in a config file. I want to use multiple commands using the -e option to do the following. Step 1: find the first occurrence ...
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3answers
79 views

How to search multiple search patterns from a file with grep

If I search for multiple search strings in grep : usually just do: grep "search1\|search2" somefolder/*.txt but, what if I have 100 or more search strings? Can I say like this: grep ...
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48 views

Bash script to copy specific directories with pattern matching

How can I copy directories from one location to another location that matches a pattern. For example: source = /media/src/ destination = /media/dest/ The pattern is as /b/w{2}_/w{2}/b. i.e all ...
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1answer
70 views

Sed: replace text keeping digit occurrence

I have some text like: Blablabla <b>[intlink id="</b>2204<b>" type="page"] Blalala I want replace it for remove the </b> and <b>, keeping the id="number". So it should ...
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1answer
91 views

Need to capture part of file name into variable

I have bunch of CSV files named like so in a directory: s_m_u_supplemental_fields_account_9_4_2015_11_26_Error.csv s_m_u_supplemental_fields_account_9_4_2015_12_3_Error.csv ...
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2answers
56 views

Remove last comma within a pattern

If I have the following text within a file (somefile.txt): CREATE TABLE "table_name" ( "id" int(11) unsigned NOT NULL, "some_field" varchar(10), ); CREATE TABLE "another_table" ( "id" ...
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1answer
44 views

Remove word after match

Consider the following line of text (taken from a MySQL insert): "description" varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '', I want to return "description" varchar(255) NOT NULL ...
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61 views

Meaning of this character class in perl?

I am new with PERL(though I have good background in reg-ex), I was going through one perl script and it has one characters class $alwayssep = "[\\?!()\";/\\|‘]"; Can anyone explain to me what is ...
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4answers
265 views

extract url between 2 strings in a file

I have a file in which each line is like this "372"^""^"2015-09-03 06:59:44.475"^"NEW"^"N/A"^""^0^"105592"^"https://example-url.com"^"example-domain < MEN'S ULTRA < UltraSeriesViewAll ...
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2answers
330 views

How to change all strings in python file from snake_case to camelCase in sed

I've tried some sed patterns like this from commandlinefu sed -r "s/('[a-z]+)_([a-z])([a-z]+)/\1\U\2\L\3/" But somehow it's not working. For one thing they forgot the digits, which I can fix, but ...
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685 views

How to add a header and/or footer to a sed or awk stream?

I have a bunch of output going through sed and awk. How can I prefix the output with START and suffix the answer with END? For example, if I have All this code on all these lines and all these ...
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4answers
83 views

Match regular expression between delimiters

I have a file with several different lines. I'm looking for lines that contain(more or less) pattern like this: \[.*<.*>.*\] In other words, I want the lines that have <something> ...
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108 views

How to grep the following lines from a file?

I have a file which has the names of many files in a directory in the following format: A20150824.0950-0955_jambala_CcnActiveSessionCounterJob A20150824.0945-0950_jambala_CcnActiveSessionCounterJob ...
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42 views

sed: regular expression,how to substitute?

I have those line on a text file 36) SIGCANCEL 37) SIGLOST 38) SIGXRES 39) SIGJVM1 40) SIGJVM2 41) SIGRTMIN 42) SIGRTMIN+1 43) SIGRTMIN+2 44) SIGRTMIN+3 45) SIGRTMAX-3 46) SIGRTMAX-2 47) SIGRTMAX-1 ...
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Awk & regular expression to process pgn chess games file

Below an extract of the sample.pgn file [Event "rated blitz match"] [Site "Internet Chess Server"] [Date "2015.08.20"] [Round "?"] [White "Villain"] [Black "Hero"] [Result "0-1"] [WhiteElo "1643"] ...
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How to combine POSIX character classes of a regex?

I need to combine different character classes in a regular expresion used by sed. I need to match [:word:] and the minus symbol -. How does that look like? All my attempts failed at trying or ...
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what is the correct regexp for mysql filter in fail2ban?

I use the default filter file /etc/fail2ban/filter.d/mysqld-auth.conf for fail2ban service. But there are some errors in file /var/log/fail2ban.log as: Found a match for '150815 10:42:54 [Warning] ...
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133 views

How to use sed to replace keys in a file using a regex?

I would like to modify a file to replace keys, suppose these keys are in the file as: 42NM 52NM 23NO XNNM I would like to replace anything with NM, with the word "Okay". 1 #!bin/bash/ 2 3 if [ ...
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241 views

POSIX behavior of sed's ^ and $ regex anchors with multiline pattern spaces

What is the POSIX behavior of the sed ^ and $ anchors when used at the beginning and end of a regex if the pattern space contains embedded newlines, like after you use the N command? Should they ...
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230 views

AWK, SED or GREP for extracting data from HTML file

Can anyone tell me which is best to use to extract the following data from a html file which was received with curl . <script>document.getElementById("test-summary").innerHTML = ...
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Censor text with regex

I'm currently running this command to censor an indented to-do list. sed -e 's/\(\s\+- \)\(.*\)/\1XXX/g' It's great except that I'd like the number of Xs to match the number of matched characters. ...
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423 views

What's wrong with this grep?

> output2.txt cd # some directory i'm trying to search find views/shared -type f -name "*.js" -print0 | while IFS= read -r -d $'\0' line; do echo -n "${line%.js}" | tee -a ...
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58 views

Remove words (letters followed by space) from a specific column

I have a file and the format is as follows: cat dog AHF123432 | 123432 | dhfshfjdh lion AFG23412 |23412 | dfshjhfjdhj I need to remove those words from first column which contains only alphabets ...
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What is the effect of the underscore in [A-Z] [_a-zA-Z0-9]*?

In regards to regular-expressions what is the effect of the underscore in [A-Z][_a-zA-Z0-9]*
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Bash script with “execute” command and strange regexp

So I was looking through Paul Irish's dotfiles and found reference to this bash script: #!/bin/bash cd "$(dirname "$BASH_SOURCE")" \ && source 'utils.sh' declare -a FILES_TO_SYMLINK=( ...
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1answer
38 views

How to express “There is a specified symbol in the following unknown numbers of characters” in regex(vim)?

I have many python code examples in my markdown files, which should be prepended with >>> symbols. So I write a vim function to do this job: function AddShellPrompt() range let lnum = ...
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250 views

How to use regex inside exec with find?

Is it possible to use regular expressions based on the result (file name) inside the exec argument with find? I want to be able to "exec" based on parts of the argument, like: find . -name pattern ...
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1answer
59 views

grep also returning non matching lines

I'm trying to grep the output of strings and only find lines that start with a certain number of = chars. I tried strings data.txt | grep ^=* Sample output: 1~{, WX2 };K,< ========== ...
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235 views

Grep and ignoring leading whitespace

I've been working on a bash script to search for names of defines, and then grab the hex values for them and put them in the list. Once I have the list of names I'll attempt to search for "#define ...
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6answers
398 views

Grep the text which matches with a pattern

I was looking for a command which will print the selected portion of a line which matches the conditions. Eg, my text line is like this: p1=X||p2=Y||p3=X||p4=X||p5=X||p6=Y||p7=X I want to print ...
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59 views

sed - find string made of 4 numbers with a preceding character and append character

I'm trying to build a sed command that will allow me to search and replace some values in a large csv file. I have this column which contains years, like 2005 - 2006 2001 - 2003 and so on, but I also ...
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LFTP exclude file extensions

I am trying to mirror directories with lftp but I don't want to download filetypes that are notoriously large like .mp4 and .swf. But I am having trouble with the regex - and seeming like the ...
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1answer
39 views

Locate --regex with negative lookahead

Problem I tried to implement a negative lookahead when searching a file with locate like this: locate --regex "apple(?!t)" However I'm getting the following error, because there seems to be some ...
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4answers
328 views

Replace regex match with string containing match

I have a file with text as Afghanistan=+93 Albania=+355 Algeria=+213 American Samoa=+1 Andorra=+376 Angola=+244 It has all the country list and its dialing code. I want to replace: ...
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324 views

Duplicate lines and make them unique?

I have the following structure of text lines: 3923 001 L05 LV,L05 RM 3923 002 L12 RA,L12 LA 3923 003 I06 ALL 3923 004 G04 RV,Z09 ALL but i would need this: 3923 001 L05 LV 3923 001 ...
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how to replace a sed/perl expression (change and print only matched line) with a python expression?

I have asked this question to learn how perl could replace sed. Now I want to know how the following commands (which do the same thing) would look like for python: sed -n ...
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how to replace a sed expression (change and print only matched line) with a perl expression?

I am trying to move to perl (from sed). But how can I replace this sed expression with perl in a similarly short way? sed -n '/patternmatch/s%stuff%changed%p' file I need to search for a pattern, ...
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grep for lines/files that contain exactly X chars

Here's the output of a grep command I ran: [user@localhost] : ~/Documents/challenge $ grep -i -e ".\{32\}" fileA fileB fileA:W0mMhUcRRnG8dcghE4qvk3JA9lGt8nDl fileB:observacion = new Observacion(); ...
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emacs dired regexp mark files beginning with

In Emacs Dired mode, I'd like to mark directories and files whose names begin with Addr but not files that contain Addr inside the name. I'm using RE-Builder to test my regular expressions and am ...
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58 views

Delete folders using regex

I would like to delete folders with specified regex, but I could not build a good regex. I have: /root /my-picture-2015 /my-picture-2015-1 /my-picture-2015-2 /my-picture-2015-1 ...
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Testing if files start with certain letters and contain no special character except for period at end next to file extension in a shell script

I have a shell script that runs a for loop to execute a command on multiple text files in a folder. I want to test if these files' names start with a specific set of letters (NA for instance), and ...