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

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substituting third occurrence of a pattern using sed

Here is a sed command. I want to substitute third occurrence of 00 to 11 echo "0000000000000000" | sed -e 's/00/11/3' The output is: 0000110000000000 But I thought output would be: ...
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Substituting the first occurrence of a pattern in a line, for all the lines in a file with sed

Is it possible to do it in one liner? I have an output like this: "First line" - Description " Second line" - Description "Third line" - Description " Fourth line" - Description This input ...
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397 views

How to find files with names having a long string after the first dot

My Samsung Galaxy S doesn't like files where the name contains a long string after the first dot. I guess some part of the software has a too short buffer for the file extension. How can I find all ...
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4answers
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regexp which matches all tokens independent of order

I have a quick (and hopefully simple) question about regexps. I'm trying to think of a regexp which matches all of a set of tokens irrespective of order. So for example I have a file with the names ...
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greedy and lazy regular expressions (comprehension question)

I am teaching myself regular expressions, and I got stuck at »greedy« vs. »lazy« repeatings. What I found out so far is that »greedy« means that the RegExp ...
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Renaming files to have lower case extensions with 'rename'

I'm trying to currently rename a large set of files and have been using quite kludgy methods to do so, such as: rename 's:(.*)\.MOV:$1.mov:g' *.MOV rename 's:(.*)\.JPG:$1.jpg:g' *.JPG What I'd ...
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Regex this question format into LaTeX

1. Lorem ipsun la la la? 1. Sopor 2. Stupor 3. Torpor 2. A patient has Lorem? 1. Sopor 2. Stupor 3. Somnolentia 4. La 5. Coma 3. Doesn't Response to strong external irritants is short. Tendon, ...
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find command with regex {1,2}

I have been trying to create a find command string that will find all files that end with a number 1-99 but exclude all others. e.g. I want to find myfile1 myfile99 but not myfile456 and not ...
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696 views

Match word containing characters beyond a-zA-Z

To match a word one can use \v(\w+) From the vim help :h \w: \w word character: [0-9A-Za-z_] This works exactly as described in the manual. However, I want to match words that contain ...
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847 views

File manager which is able to filter using regular expressions

Is there any graphical file-manager which supports thumbnails for linux like thunar or nautilus, which allows me to filter a directory by a regular expression. For example typing /home/user/*tex ...
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464 views

Are there zero-width assertions in sed?

Is it possible to make lookahead or lookbehind zero-width assertions in sed? I want to emulate Perl's (?=) and family. My sed is not GNU sed version 4.0.
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sed regex issue

I'm trying to replace a string in a file: $RELEASE = '1234'; The whitespace between RELEASE and the = symbol could be either spaces OR tabs. The quotes around the version number could be either ...
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rsync certain files, excluding the rest, ignoring .svn/ directory, recursively

I'm using rsync to copy some files from a share to another. Recursively, I need to: Delete files at destination that were removed from the origin Only sync php and js files Exclude every other file ...
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1answer
136 views

Using Regex in vim movment

Is there any way to use regular expression for movement in vim. For example, I want to move my cursor to the first occurrence of the pattern abc. So can I do something analogous to fa but now a ...
4
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1answer
780 views

Is there a tool in linux that allows multi-line regex expressions?

I'm wanting to find the results of a multi-line regular expression in linux. I tried grep, but like most linux utilities it's line based. Is there something similar that allows me to search across ...
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927 views

Parsing XML from a shell script

I have a datafile like this: <Key name="com.ahsay.afc.cpf.UserGroup" content="" allowMultiple="Y"> <Value name="rsv-id" inheritParentAttribute="Y" type="string" data="1328200856753" ...
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Multiline regex blank line delimiters,

I have a program which prints out data in blocks. Each block is delimited by blank lines. I would like to discard most blocks and only keep those blocks that contain something that matches a regex. ...
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extract part of string using sed

ls lib/oracle-11.2.0.3.0.txt | sed 's/lib.\([oracle.*]\)\.txt/\1/' It is giving the whole string instead of just oracle part until .txt What am I doing wrong? I can do it using awk as follows, but, ...
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472 views

Regex not matching

why this does not match..? sed -e '/--Updated?[[:space:]]+Date/d' inputfile this..: --Updated Date: 2013-11-06 15:32:13 d? is because sometimes I have Update Date, and sometimes Updated Date. ...
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Why can't find -regex match a newline?

Why does this fail? touch "$(printf "a\nb")"; find . -regex './.\n.' I also tried these, none of which work: find . -regextype posix-extended -regex '.\n.' find . -regextype posix-awk -regex ...
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How to insert the content of a file into another file (if regexp) in shell/perl

File1 Contents: line1-file1 "1" line2-file1 "2" line3-file1 "3" line4-file1 "4" File2 Contents: line1-file2 "25" line2-file2 "24" Pointer-file2 "23" ...
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How can I extract/parse a complete URL from a semi random string?

I'd like to have bash parse/extract a full URL (and only the url) from a random short string. Examples: bob, the address is http://www.google.com or https://foo.com/category/example.html is up ...
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Why do I need to escape regex characters in sed to be interpreted as regex characters?

It seems e.g. cat sed_data.txt | sed 's/\b[0-9]\{3\}\b/NUMBER/g' that I must escape characters to form a regular expression. In this case I had to escape braces in order to be interpreted as a number ...
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Using sed to find and replace complex string (preferrably with regex)

I have a file with the following contents: <username><![CDATA[name]]></username> <password><![CDATA[password]]></password> ...
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History of Bash globbing

Is there a historical reason why Bash "globbing" and regular expressions are not identical? For example, I believe that in Bash [1-2]* matches anything that starts with a 1 or a 2 followed by anything ...
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Delete XML node containing certain element

I want to remove all Placemarks from a KML file that contain the element <tessellate>. The following block should be wholly removed: <Placemark> ...
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How to “grep” a string of a returned result

How to grep the number 50.0 from the string temp=50.0'C In JavaScript I can use the expression /temp=(.*?)'C/ to get it. But I cant get it running in grep.
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How to use restricted characters in egrep?

I'm trying to use a regex in egrep on Centos 5.10, based on the one I made from this question on SO. T12345 .{1,100}[\n\r].{1,100}2014.03.04 I can successfully match the regex to the content in my ...
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727 views

“grep: Unmatched [” error when using regex

I'm trying to find a pattern similar to this: tail -n 100000 gateway.log | grep -B10 -A10 'Nov 22 11:13:56 Received Packet from [10.50.98.68' Where "11:13:56" could be any time. This is what I ...
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5answers
619 views

changing pattern of a text file

A text file has contents something like chair table pen desk Now i want it to be changed and stored in a variable say var as below ('chair','chair'),('table','table'),('pen','pen'),('desk','desk') ...
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Awk: check for length of field

In awk. I am working on Solaris 10, so it's probably an old(er) version of awk. I came up with this rudimentary one-liner that works, at least for my particular input. awk -F\; '$3 ~ /[ ...
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Using regex inside if clause in bash

Look at this if block: #!/bin/bash str="m.m" if [[ "${str}" =~ "m\.m" ]]; then echo "matched" else echo "not matched" exit 1 fi exit 0 This should print "matched", but it doesn't. ...
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Applying a regex to stdin

In programing we often see the use of Regular Expressions. One of the most common forms is: newText = text.replace( /regex/, 'replacementString' ) If stdin is text and stdout is newText, what ...
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224 views

Regex match in CLI

Is there something like a logical for the cli? I want to achieve this mv -t newfolder *.(png|jpg) so that alls jpg and png files are moved into newfolder. I know it could be done with mv -t ...
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926 views

Extracting text from a text file in bash

I have a large text file that is all one line. In the text are several sections that looks like foo=12345 and I need to extract them all as separate lines, ignoring the rest of the file. For ...
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193 views

sed - how to (not) match unmatched brackets

How can I do my operation only on lines that close their brackets? For example I want to change ".is" lines and add a bracket but not for lines with unclosed brackets. so these are changed ...
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342 views

Replace all occurences of \ except \N

I have a file like this: 1,2,subjects,\mat\hs,unix\,\Nato,\N,123,\N I want to replace all occurences of \ with #, except for \N, such that the output looks like this: ...
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283 views

Do procmail recipes have an alternator “or” operator?

Given the following procmail recipe: :0: * ^Subject:.*viagra.* * ^From:.*viagra.* /dev/null Procmail would only delete emails that were both from viagra, and had viagra in the subject. Is it ...
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What is the usage of pattern before substitute command in sed

There is an example in this link about sed: To delete the first number on all lines that start with a "#" use: sed '/^#/ s/[0-9][0-9]*//' What is the benefit of first pattern(/^#/)? It could be ...
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votes
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646 views

Find files starting with ~$ (MicroSoft Word Temp files)

For some reason my machine is full of M$ Word temporary files such as: ~$Filename.docx ~$AnotherFile.docx Can someone suggest a find/regex command to search $HOME and delete them?
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splitting textfiles according to a regular expression

By pasting into a text editor, I have a textfile gleaned from an online edition of Wilhelm's Yi Jing translation which I now want to split into 64 unequal parts, according to the 64 hexagrams of the ...
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sed one-liner to delete everything between a pair of brackets?

I am working with some text that is full of stuff between brackets [] that I don't want. Since I can delete the brackets myself, I don't need the one-liner to do that for me, but I do need a one-liner ...
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2answers
78 views

Extract specific set lines matching a rule

I have a large file with the logs as shown below. There are about 30000 instance of such events logged. I need to extract those lines beginning with RINGING and CLOSE (included) and which does NOT ...
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4answers
664 views

Sort input file by the results of a regex

I'd like to sort a file based on the results of a regex expression. For example, if I have the following property declarations in Obj-C @property (nonatomic, strong) id <AlbumArtDelegate, ...
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simple command to strip header and footer from a file

I want a simple little command to strip an XML-Header and Footer from a file: <?xml version="1.0" encoding="UTF-8"?> <conxml> <MsgPain001> ...
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In a regular expression, which characters need escaping?

In general, which characters in a regular expression need escaping? For example, the following is not syntactically correct: echo '[]' | grep '[]' grep: Unmatched [ or [^ This, however, is ...
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573 views

ANDed conditional using regexp and variables

I want to test whether a line, read in from a file, has a specific beginning AND an ending containing a word held in a variable. Here's some code: The input file is: line one #; line two #; line ...
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141 views

Replacing a pattern in line preceding another pattern of interest

I have a log file with many instances of statements as shown below: 14 Aug 19 16:30:11.506: <DATA> |POS|IDLE|1|01131844090|5950|$hostIp|$size |$data 20 Aug 19 16:30:12.439: <DATA> ...
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Replacing string in all files found by grep. Can't get it to work

I'm trying to do what title says. So I find all needed files with grep: grep --include=\*.{php,ini,conf,sh} -ril -P "'([\d\w\-\_\.]+)(@domain.com)'" '/var/www_data/somepath/' Now I assume it's ...
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203 views

Why doesn't this regex work?

I want to look at the output of git status -s to determine whether there are any untracked files in the tree. I tried the following test, but the regex doesn't match. Why not? $ git status -s ## ...