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

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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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grep and escaping a dollar sign

I want to know which files have the string $Id$. grep \$Id\$ my_dir/mylist_of_files returns 0 occurrences. I discovered that I have to use grep \$Id$ my_dir/mylist_of_files Then I see that the ...
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1answer
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Bash regex matching not working in 4.1

Upgraded to Bash4 and found that it is not matching regexes: $ echo $BASH_VERSION 4.1.2(1)-release $ [[ "20110228" =~ "^[0-9]{8}$" ]] && echo matches But Bash 3.0 is: $ echo $BASH_VERSION ...
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3answers
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How can I find and replace only if a match forms a whole word?

My script is: n="y" while [ "{n}" = "y" ] if [ $n == "n" ]; then break; fi echo "n is $n" do read -p "Enter the word to find = " word read -p "Enter word to replace = " replace ...
4
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1answer
85 views

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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1answer
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lftp exclude syntax confusion

I am confused with the syntax description given for lftp from their website: -x RX, --exclude=RX exclude matching files -X GP, --exclude-glob=GP exclude matching files How ...
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3answers
1k 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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4answers
228 views

Replace using vim - Replace a pattern […] by a string

I have a file containing lines in below e.g. format - [foo@host.com, bar@host.com], Payment processed - 23499, params = {'invoice':3243} I only want the account numbers i.e. 23499. It's a number. ...
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2answers
150 views

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 ...
4
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1answer
187 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
887 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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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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5answers
448 views

How to grep the n-th substring between given delimiters?

Let's say we have a string and its delimiter is ?: Leslie Cheung April 1 ? Elvis August 16 ? Leonard Nimoy February 27 I know how to grep the first substring between delimiters: echo $above_string ...
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4answers
368 views

Decreasing a number with sed

I extracted the metadata of a PDF in a .txt file using pdftk, and now I am trying to decrease the BookmarkPageNumber value for each bookmark by an integer. The .txt has these lines: BookmarkBegin ...
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Regex that would grep numbers after specific string

So I have a line: ID: 54376 Can you help me make a regex that would only return numbers without "ID:"? NOTE: This string is in a file.
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387 views

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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3answers
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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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3answers
969 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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3answers
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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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2answers
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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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“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
762 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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3answers
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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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1answer
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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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Why awk understand FS=“*” but not for FS=“-*-”?

I got a test file, its content is: a -*- b I used awk 'BEGIN {FS="*"} {print $2}' test, it prints out - b Correct! But when I use awk 'BEGIN {FS="-*-"} {print $2}' test, I got: * I know that ...
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249 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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3answers
694 views

Find word in sentence with Bourne Shell (sh)

I'm trying to determine if a particular word appears in a sentence using Bourne Shell (sh). For example: #!/bin/bash INPUT='Lorem ipsum dolor sit amet.' if [[ "$INPUT" == *dolor* ]] then echo ...
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3answers
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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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117 views

Undo letterspacing with sed

I have a source text file containing text where some words are l e t t e r s p a c e d like the word "letterspaced" in this question (i.e., there is a space character between the letters of the word. ...
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4answers
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pattern match and capturing in unix

I have a file like this: A1-1915435_1_MIMAT0000069_MirBase_miR-16_microRNA_1_22-A1-1915435_1_ENSG00000206737_ENST00000384010_U1_snRNA_73_115 ...
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3answers
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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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4answers
488 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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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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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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votes
1answer
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Invalid back reference using grep

So I am trying to find 6-letter words that consist of one character repeated three times followed by another character repeated three times. For example aaabbb or oookkk. I am trying: grep -E ...
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votes
2answers
109 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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3answers
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Checking if an input number is an integer

I'm trying to check if an input is an integer and I've gone over it a hundred times but don't see the error in this. Alas it does not work, it triggers the if statement for all inputs ...
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2answers
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Using a variable in a regex

How can I use a variable string in a regular expressions while read line do if [[ line =~ *"$key"* ]]; then echo line fi done < "$filename" $key is a string ...
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2answers
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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> ...
3
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2answers
685 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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sed or tr one-liner to delete all numeric digits

So, I have this textfile, and it consists of mostly alphanumeric characters. It's a standard document. But since I copied it and pasted it from a PDF, there are page numbers in there. I don't much ...
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3answers
760 views

Strip off word pattern at the end of string using sed

I have following string: ksh -x SCRIPT2.ksh $BUSSINESSDATE & PID=$!; ksh -x SCRIPT1.ksh $BUSSINESSDATE & PID=$!; I want to strip off the last word & PID=$!;. Desired result is: ksh -x ...
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2answers
181 views

Sed: modify every non-first word repetition for every word in text

Can you help me to do something like that using sed? qq ab xyz ab qq aa ab Becomes: qq ab xyz +ab+ +qq+ aa +ab+
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3answers
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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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3answers
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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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1answer
363 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 ## ...