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

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7
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VIM see regular expressions matches as you type

If I type /regex then the cursor temporarily jumps to the first match and all matches are highlighted. This updates as I type. Is it possible to get this behavior when I'm getting ready to make a ...
2
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1answer
320 views

How to join vCards lines

vCard uses a special way to split long lines: At 75 characters, insert a DOS newline and a space. Joining therefore means to replace all occurrences of the sequence "CR, LF, space" with an empty ...
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2answers
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Sort by regular expressions

I've got a set of POSIX regular expressions* ^BEGIN:VCARD\r$ ^VERSION[^A-Z] ^FN[^A-Z] ^N[^A-Z] ^NICKNAME[^A-Z] ^EMAIL[^A-Z] ^X-\([A-Z-]*\) ^TEL[^A-Z] ^ADR[^A-Z] ^ORG[^A-Z] ^TITLE[^A-Z] ^BDAY[^A-Z] ...
2
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2answers
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How to do a regex search in a UTF-16LE file while in a UTF-8 locale?

EDIT: Due to a comment Warren Young made, it made me realize that I was not clear on one quite relevant point. My search string is already in UTF-16LE order (not in Unicode Codepoint order, which is ...
2
votes
1answer
579 views

Emacs: query-replace, regular expression, reuse of search result

How do I combine something like query-replace with a regular expression search-and-replace that in part reuses the search result? In my case, how to transform The programmers are "sort of" ...
0
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2answers
208 views

Difference in regular expression handling between Perl, Kikki, and Kodos

#!/usr/bin/perl $mystring = "[2004/04/13] The date of this article."; if($mystring =~ m/(\d+)/) { print "The first number is $1."; } Perl returns 2004, but Kiki and Kodos return /04/. Why ...
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2answers
579 views

Weird zsh grep -P behaviour

I connect to server with PuTTY from Windows. I have a long yet not touched (I suppose) by hands of local admin config: $ cat /opt/jira/.subversion/config ... ### must be enabled, which is ...
13
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5answers
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How to remove the (1) from filenames using the find command

I recently converted all of my FLAC files to a lower sampling rate of 44.1 kHz and bit depth of 24 bits (because iPhone/iPod don't support anything above that) using XLD on my Mac OS 10.7 (Lion). ...
0
votes
1answer
116 views

Replacement in VIM with regular expression matched part unchanged

Suppose I want to append two digit numbers in my file with "some_thing". Like from this: 12 23 45 to 12_something 23_something 45_something How can I do this using regular expression ...
2
votes
2answers
371 views

Detect pattern repetition in a file

I want to make sure a file follows the following pattern: ... ... ... foo ... foo_KO ... ... ... bar ... ... ... ... bar_KO ... The file is extremely long, so, in other words, I want to make sure ...
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2answers
421 views

How do I generate a list of the characters occurring before a certain character only in lines that contain another certain character using regex?

I know that's super confusing (total noob-sorry!). To clarify, I have a text file that looks like this: 407-OL? 408-2-OL? 408-OL? 418-het? 420-1 and 2- OL? 429-2-left unscored? 430-2-left both ...
4
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1answer
352 views

match files based on an md5 using find

I have a bunch js and css files in a directory. Some of them have been given a name based on an md5() of their content (looks like f10521a21bb013cb81e0909809818ad6.js). I'd like to match these files ...
4
votes
1answer
2k views

escaping a single dot with double backslash - awk

"effective awk programming" book has an example on Field-Splitting. here is the example: If you want fields to be separated by a literal period followed by any single character, use ‘FS = ...
2
votes
1answer
290 views

Why doesnt ctrl+d work with this?

I wanted a simple way to process text in my clipboard without having to create a file. I tried using the following line: awk '{print $1}' <(cat) but I couldn't send cat the EOF character using ...
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3answers
2k views

sed pattern matching

I recently asked someone at work about how to take the output of ipcs -qa and make it space delimited, so I can parse it/store it in the database for monitoring. He gave me this: ipcs -qa | sed 's/ [ ...
2
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2answers
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How do I transfer multiple files with a common suffix and prefix using an offset?

I have thousands of files whose names are of the form: sequence_1_0001.hmf sequence_1_0002.hmf sequence_1_0003.hmf ... sequence_1_0001.jpg sequence_1_0002.jpg sequence_1_0003.jpg ... ...
5
votes
4answers
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Recursively rename subdirectories that match a regex

I have a media server with a folder called Series. (/media/Expansion2/Series/) In it, I have (surprise!) TV series. These are just the show names, e.g., /media/Expansion2/Series/The Big Bang Theory/ ...
33
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4answers
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How do I grep for multiple patterns?

I want to find all lines in several files that match one of two patterns. I tried to find the patterns I'm looking for by typing grep (foo|bar) *.txt but the shell interprets the | as a pipe and ...
4
votes
1answer
280 views

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: ...
2
votes
2answers
1k views

regex replace text in xml file within node from the command line

I have an XML file and I would like to replace everything that is between the open and closing tag within multiple instances of the g:gtin node with nothing. Is this possible from the command line, ...
2
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1answer
252 views

Delete repeated words between brackets inline

Our input looks something like 2012-04-17 [GBPGBP] 2012-04-13 [GBP GBP] 2012-04-13 [GBP] 2012-04-11 [GBPGBP] 2012-04-11 [GBP GBP] 2012-04-10 [GBPGBP] 2012-04-06 [GBP GBP GBP] 2012-04-17 ...
1
vote
1answer
626 views

Multiply certain numbers in a text -file by certain constant

I want an alternative solution to this jQuery hack, tasting a bit reinventing the wheel -- look I am sure I could do this with some one-liner using basic *ix tools. Look much easier and ...
3
votes
2answers
98 views

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 ...
4
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1answer
3k views

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 ...
3
votes
2answers
644 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?
2
votes
2answers
391 views

Regular expressions with ExpectJ

I've been used the ExpectJ Java library to automate some jobs on a Linux server, however now I need to automate a job that sends a different text response for each execution. Here is the output: Last ...
5
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1answer
4k views

Replace using VIM, reuse part of the search pattern

I am working with VIm and trying to set up a search and replace command to do some replacements where I can re-use the regular expression that is part of my search string. A simple example would be a ...
9
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6answers
846 views

Text Manipulation Across multiple lines

I Have a file that has text like this: AAAA BBBB CCCC DDDD 1234 5678 9012 3456 EEEE 7890 etc... And i want to match up the Alphabetic lines with the Numeric lines so they are like this: ...
1
vote
1answer
672 views

What does this egrep command do?

What does this egrep command do? egrep '[^A-M][0-9]+' /etc/passwd So far I think it searches for any file in /etc/passwd that starts with A-M and includes the number(s) 0-9. Is that right?
3
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1answer
227 views

Character classes: construct my own

I want to construct my own character class in a script, then modify (and use) it, for example: [:myclass:] contains a, *, \n (as linefeed) and [WHITESPACE]. I want to add all characters to ...
2
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2answers
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Sed: replacing digits

I am trying to write some install scripts for when I install/upgrade Ubuntu. I'm having trouble with fixing logrotate.d: /var/log/ufw.log { rotate 7 weekly missingok notifempty compress delaycompress ...
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votes
4answers
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Finding text between two specific characters or strings

Say I have lines like this: *[234]* *[23]* *[1453]* where * represents any string (except a string of the form [number]). How can I parse these lines with a command line utility and extract the ...
2
votes
1answer
625 views

remove trailing zeros in awk not working. syntax error

regex = "\\.*0+$"; subst = ""; system("echo "id "| awk '{sub(\\.*0+$," subst"); print}'"); It is giving the following error: awk: cmd. line:1: {sub(\.*0+$,); print} awk: cmd. line:1: ^ ...
3
votes
4answers
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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" ...
3
votes
3answers
923 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 ...
6
votes
1answer
6k views

grep for words of no more than a certain length

I'm looking for a way to grep things like: i log for E M, i 1 f x i 0, I xi 1, 3 1,. simply based on number of characters. Nothing in that hypothetical output is longer than three characters. This ...
4
votes
2answers
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What is the python equivalent of grep -v?

I like grep -v. I use it all the time. But I am also doing some text processing in python, and there is one crucial thing that I lack. Usually, I use grep -v to take extraneous stuff out of text. ...
3
votes
5answers
618 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') ...
3
votes
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 ~ /[ ...
3
votes
1answer
1k views

Escaping of meta characters in basic/extended posix regex strings in grep

Is it possible to escape all meta characters of a string inside a variable before passing it to grep? I know similar question has been asked before on SE (here) and also a good explanation here, but I ...
5
votes
2answers
703 views

regex wanted to exclude a string

I want to have an expression that targets all lines that begin with http, end with icon.ico and do not contain config.privoxy.org. In the sample list below, I would like to catch all except the third ...
7
votes
2answers
1k views

Number of backslashes needed for escaping regex backslash on the command-line

I recently had trouble with some regex on the command-line, and found that for matching a backslash, different numbers of characters can be used. This number depends on the quoting used for the regex ...
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votes
2answers
7k views

Find all lines in a file with a certain character at a certain position

I have a lab question asking me to use grep with a regex pattern to match every word where the third letter from the beginning of the line is an "a" and save it with a redirect. How can I do that?
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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. ...
2
votes
1answer
125 views

Does find support OR in its regexes?

For example, I want to find all files in a directory that end in 'm' or 'sh'. The following works correctly: find . -regex '.*.m' -o -regex '.*.sh' But this fails: find . -regex '.*.(m|sh)' What ...
3
votes
1answer
7k views

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 ...
0
votes
1answer
971 views

Egrep: contains and does not contain

egrep -i '12-12.*\swarning' log.file | cless The above will produce two lines with the date 12-12, followed by random characters, a white space, then Warning and more text. 2011-12-12 textetc ...
6
votes
1answer
4k views

What is the .gitignore pattern equivalent of the regex (Big|Small)(State|City)-[0-9]*\.csv

I have a regex I stuck in my .gitignore similar to: (Big|Small)(State|City)-[0-9]*\.csv It didn't work so I tested it against RegexLab.NET. I then found the gitignore man page which led me to ...
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3answers
370 views

grep equivalent of the kwrite regex [A-Z][A-Z]+

So, it took me ages, but I finally learned to think in terms of regular expressions, thanks to using them in kwrite. But I still don't know how to translate that knowledge to grep. I love my grep, ...
7
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3answers
7k views

grep: Trailing backslash

I want to do a grep for \resources\. How do I do this? I've tried: grep \resources\ grep \\resources\\ grep "\resources\" grep "\\resources\\" None of these work.