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

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how to exclude range of numbers using regular expression

I'm trying to write a regular expression in order to cover all numbers starting with 1809 and excluding some ranges: Ranges needed to be excluded Starting with 1809 and followed by: ...
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To visualise look-behind in this Regex

I am using Regexr to visualise my regexes now. I need look-behind but Javascript does not support it, example code here. The project code base seems to be dependent Javascript (NodeJS) in Github. I ...
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Find & replace image URLs in one file from another file

I am trying to replace all the image source URLs in an HTML file from a list of URLs in a text file. File1.html <td class="MetadataRes" width="380px" colspan="2" style="border-top: 1px #336699 ...
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63 views

add bracket across numbers at only end of each line

I have a file having lines as: ram_reg_10/raja_reg_9/raghu_reg_8 abc_reg_4/bcd_reg_5 cad/pqr_reg_91 I want to convert string "_reg_number" into [number] at only last of every line in vi ...
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125 views

Finding and replacing text inside awk block

I want to find and replace a value inside awk block. Here is a sample input file to my script P1 10,9:11/18013013582 ,10:1 ,167:0 ,487:5/E.164 11,9:15/310410532169026 ,10:60 ,167:0 ,487:4/IMSI ...
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Using regex in locate [duplicate]

I would like to search for both words pdf and hack in all filenames and their paths. The order of the two words doesn't matter. I use the command locate with a regex pattern: locate --regex ...
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218 views

Search for pattern across multiple files and replace a sub-part in all occurences

I am helping a friend with her thesis written in LaTeX and I need a quick solution for a "search and replace". Using a terminal in Linux, how can I find the following pattern: \caption{*\cite{*}} ...
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How can I use gsub with a pattern? And how to tell it which file to awk?

I've read here that I can replace the values of all columns containing a particular text using awk -F'\t' -vOFS='\t' '{ gsub("CC", "C", $1) ; gsub("AA", "A", $1) ; print }' But where do I tell awk ...
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what is “an invisible whitespace character that takes up space”

One can look up Unicode Characters with Regular Expressions. On Jan Goyvaerts website I found a RegExp whose meaning I don't understand : \p{Zs} or \p{Space_Separator}: a whitespace character that ...
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584 views

Remove a block of lines between two patterns [duplicate]

Possible Duplicate: Show only text between 2 matching pattern In a bash script using sed how can I remove a block of lines beginning with -pattern a- and ending with -pattern b- where the ...
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Meaning of asterisk (*) in grep

[USERNAME@host ~] echo -e 'prdxxx\ndadxxx' | grep "da*xxx" prdxxx dadxxx [USERNAME@host ~] echo $SHELL /bin/bash [USERNAME@host ~] dpkg -l | grep -iw bash ii bash ...
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How to exclude directories from `ls -R` output?

If ls -aR | grep ":$" returns ./.hiddendir2: ./dir1: ./dir3: ./dir3/.hiddendir4: then how can you update the pattern given to grep so that you only get ./dir1: ./dir3: (note that the last ...
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353 views

How to remove a newline character in a particular line through perl?

I want to remove a newline character in a particular line through perl one-liner command. Input: 1407233497,1407233514,bar 1407233498,1407233515,foo mingstats&fmt=n 1407233499,1407233516,foobar ...
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How to get `expr match` to extract colon-delimited key-value pair?

Given: myvar="present-value: 1", I'd expect expr match "$myvar" '\([0-9]\)' to output 1. However, instead it outputs blank and exits with a non-zero status code indicating no match. How can I get it ...
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3answers
277 views

Removing second colon

Trying to create a simple script that lists mass mailing by the queue number that appears in /var/log/maillog. I'm starting off with this: [root@ditirdlns01 ~]# lsMails(){ grep -i ...
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387 views

Regular expression to mask credit card digits in a file

What is the most simplest way to mask all numbers but the last 4 digits of a credit card number in a file using sed. Using egrep with the following regular expression we can find numbers of Visa, ...
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Regular expressions in a shell [duplicate]

I have two questions about using regular expressions inside a shell. 1. Use of * According to wikipedia page on regular expressions: *: The asterisk indicates there is zero or more of the ...
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349 views

extracting ip address from a file [closed]

I'm trying to extract all the IP address from a file. FILE *>i85.95.2.160/29 172.16.24.4 0 200 0 64515 4445 15412 i *>i85.112.80.0/28 172.16.24.4 0 200 ...
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1answer
513 views

How to “grep -v” private/broadcast IPv4 addresses?

time nmap -n -iR 0 -sL | cut -d " " -f 5 | egrep -v "^10.*|^172.[16\-32].*|^192.168.*|^[224\-255].*" > RANDOM-IPS.txt so the important part is: egrep -v ...
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Is it possible to get static backreference with grep?

I try to match a a group twice in multiline. grep -Pz 'Source: (?<group>.*/).*\n.*\n.*\n.*\k<group>|$' it work except one major problem - it doesn't, \k<group> search for .*/ and ...
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44 views

SMTP log anonymize script

I have a SMTP log with records in the format below: 6,222.3.4.5,3040,100.2.3.4,25,UNKNOWN,0,1,……,9337bc-929a-34c0-29a8-b3a89c834b29 ,protocol,SMTP ,745663746,STATUS-COMPLETE ,VALID ...
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116 views

Regular expression in unzip files argument not working

I'm trying to view the contents of a zip archive using an extremely simple regular expression. This works: rmorton@Rockette:~$ unzip -l Downloads/WeiDU-Linux-236.zip "*/i386/tolower" "*/i386/weidu" ...