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

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239 views

Replacing 3 or more digits with equivalent number of *

I want to replace any 3 or more digit string in a text file with equivalent number of *.For example: abc-1234-45 --> abc-****-45 echo "abc-1234-45" | sed 's/[0-9]\{3,\}/*/' I tried this but it only ...
3
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1answer
219 views

Expanding comma-separated list into separate lines

I have a file with some data in this form: Prefix text: First Name, Second Name, Third-- The prefix differs by line. The number of names varies from one to several. The suffix (-- in the example) ...
3
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1answer
1k views

How to insert both vimscript variable and string into vim search and replace

I've only just found out about Vimscript's existence as of today, so forgive me if this question is more basic than it seems, but I've been struggling to find an answer to this question for the better ...
3
votes
1answer
3k views

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 ...
3
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2answers
761 views

Using grep/sed/awk to classify log file entries

I need to process a very large log file with many lines in different formats. My goal is to extract unique line entries who have the same starting pattern, e.g. '^2011-02-21.*MyKeyword.*Error', ...
3
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1answer
125 views

How do back-references match in sed?

I found a one-line sed command on this site which removes duplicate entries in $PATH. There is one concept that I can't get my mind around. It uses saved matches in the match section to detect the ...
3
votes
1answer
305 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 ...
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1answer
1k views

How to block the Google Analytics Script using Privoxy

Related subject: Privoxy: blocking twitter, facebook and google outside of their domains + HTTPS Never mind what rule I am adding to the default.filter file, I don't make it to block these scripts. ...
3
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2answers
74 views

How can I exclude a string using a regular expression?

I have this file named test: http://edge.sharethis.com http://edge.sharethis.com https://timetosa.com http://timetosa.com https://webtest.es holahttp.com timetosa I want a expression that excludes ...
3
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2answers
135 views

Coloring tail output with perl

tail -f logfile.log | perl -pe 's/.*foo*/\e[1;41m$&\e[0m/g' will color all the lines containing the pattern "foo" in the logfile.log file. How can I make use of this in order to highlight ...
3
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3answers
97 views

Parsing Log Files with sed -e. Need to count unique class names

I have a file, let's call it filename.log, in it I have something like this (2014-11-18 14:09:21,766), , xxxxxx.local, EventSystem, DEBUG FtpsFile delay secs is 5 [pool-3-thread-7] (2014-11-18 ...
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3answers
475 views

How can I get the first column of a 300GB txt file?

let me first explain my problem in detail. It's actually pretty simple. I have a huge .txt file, 300GB to be more preciese, and I would like to put all the distinct strings from the first column, that ...
3
votes
4answers
3k views

Change filename from lowercase to uppercase recursively

I have 1,000,000 files in some folders and subfolders. I want to rename them from lowercase to uppercase using shell commands. I don't want to modify the extension. only filename part. I have found ...
3
votes
2answers
956 views

Wget - Mirroring a full website with requisites on differents hosts

I am trying to make a full static copy of a wordpress website with wget to be browsed without any network connection (all links and images must be converted). The different requisites for the pages ...
3
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1answer
294 views

Ex and Vi: buffers and regexes

I want to put regex matches to buffer but cannot get even simpler example y :.put myNewBuffer return msg [line] [put] [buffer] working ie how to put something to buffer? So to regular expressions ...
3
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0answers
131 views

How to use regrex with AWK for string replacement in this example? [duplicate]

Possible Duplicate: How to use regrex with AWK for string replacement in this example? Suppose there is some text from a file: (bookmarks ("Chapter 1 Introduction 1" "#1" ("1.1 Problem ...
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6answers
4k views

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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4answers
295 views

remove leading string in bash

I try getting this sed command to work. I have a string like rev00000010 and I only want the last number, 10 in that case. I have tried this: TEST='rev00000010' echo "$TEST" | sed ...
2
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3answers
2k views

sed one-liner to delete any line that begins with a digit

Pretend I am working with this file. The beginning of the first visible line is obscured, so ignore that. 43 is the beginning of the next line, and that line would be deleted. The next line (which ...
2
votes
3answers
821 views

sed, grep, or tr command that returns only Latin characters from a UTF-8 file

I am working with the text of the 300 tang poems, which unfortunately is a single file containing both Chinese and English. Since I am interested in 'extracting' the English, I hope to use sed, ...
2
votes
4answers
3k views

Can tr work with regex?

I have a file like this: AAAA BBBB CCCC DDDD etc Words in separate lines. I want to add them quotes using tr. So I tried the following: 1) To add a quote in the start of each word ...
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votes
2answers
1k views

How to find files with a certain subpath?

I need to find all xml-files that are placed in folders named config. Also config must be somewhere under a folder named trunk. For example, I am interested in all files like below: ...
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5answers
1k views

Remove backslashes from a text file

I have Input: NISHA =\455 Output: NISHA = 455 I want to remove \ from output. I tried to use command sed "s/[\]//g" P but it is not working and it flags an error: character found ...
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2answers
228 views

How can I remove lines matching foo but not matching bar?

Assume I want to remove the 2nd and 3rd, but not the 4th line in the following file (those which match foo but do not match bar), can I easily do this with e.g. sed? text foo some more text even more ...
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3answers
128 views

Apply item replacement inside enumerate in Perl regex?

Data 7. Masi is the same as \begin{enumerate} A B ABC ha lorem \end{enumerate} 1. ABC is \begin{enumerate} P B Lorem maam \end{enumerate} which I want to be 7. Masi is the same as ...
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4answers
2k views

Extract IP address from a string

The Linux host command returns: hostA.domain.com has address xx.xxx.xxx.xx How do I get just the IP address and put it in the $ipaddr variable? open(FILE, "hostlist.txt") or die("Unable to open ...
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2answers
767 views

SED change only start of line and preserve end of line

Basically I have a situation where I frequently need to modify my hosts file to access different servers at my workplace. In an attempt to automate the process. I've been trying to use sed to make the ...
2
votes
3answers
117 views

Pulling out keywords using standard command line utilities?

As an example, this is the pronunciation of "when" according to Wiktionary. enPR, IPA and X-SAMPA are different schemes for showing pronunciations. when:* {{a|US}} {{enPR|wĕn|hwĕn}}, ...
2
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3answers
659 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 ...
2
votes
3answers
907 views

Yum regular expression or wildcard search?

Fedora documentation says: 5.2. Advanced Searches If you do not know the name of the package, use the search or provides options. Alternatively, use wild cards or regular expressions with ...
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1answer
441 views

Regex doesn't work with grep

I have a string like this TEST="/dev/sda1 on /media/sda1 type vfat (rw,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=cp437,iocharset=iso8859-1,quiet)" (Result from mount | grep sda1) ...
2
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2answers
171 views

Why don't I need to escape a character class in sed but I need to escape the rest?

I am confused with sed. I had a file with the following contents: [ 2014/02/10 14:45:15 | INFO ] Saving data for customer: 273667 [ 2014/02/10 14:45:15 | INFO ] Saving data for customer: ...
2
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2answers
232 views

Understanding -regex with GNU find

Background I have what I think should be a simple case. I want to find all files with "cisco" in the name and do something with those files (via xargs). Finding files with ls Before I use xargs, ...
2
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6answers
6k views

Extract substring using regular expression on a Unix file

I have file with below contents . /ABC/RTE/AD_900_VOP_123/OPP /ABC/RTE/TRE/AD_900_VOP_145/BBB /ABC/RTE/AN_900_VFP_124/FBF /ABC/RTE/HD_900_FOP_153/WEW /ABD/RDV/AD_900_VOP_123/OPP ...
2
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3answers
354 views

awk, sed, grep, perl… which to print out in this case?

I have this syntax in a file (http response times from analog): <thead><tr><th class="x">seconds</th><th class="R">reqs</th><th ...
2
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2answers
486 views

changing pattern by removing spaces?

file : hi hello,new york, , ,brazil site ,brazil january,month is feb , , ,indiana jones task: delete all horizontal space (spaces and tab) between any two comas (like , ,) if ...
2
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2answers
434 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 ...
2
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3answers
389 views

bash - extract filenames from html file containing multiple links

I have downloaded an html file autogenerated by a script on a webpage. The file contains multiple links, including links to images I am trying to extract the full names of the images, for example ...
2
votes
1answer
290 views

sed regexp HEX char

i have this string: echo -e "a12\x8fb12\x9f"|xxd 0000000: 6131 328f 6231 329f 0a a12.b12.. i want delete this sequence string 12\x9f and 12\x8f with sed. i can do it with this ...
2
votes
3answers
501 views

Find a pattern with no repeated numbers in egrep

I need help finding a regular expression to match all digit sequences which has no repeated digit. Example: 198345 -> matched. 198315 -> not matched (1 repeated twice ) How can I achieve this in ...
2
votes
1answer
3k views

Forcing Bash to use Perl RegEx Engine

As you may already know, a lot of the features modern RegEx engines support (back referencing, lookaround assertions, etc.) are not supported by Bash RegEx engine. Following is a simple Bash script I ...
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votes
2answers
1k views

extract last match from logfile till end

Using sed, grep, awk, or ruby, what's a simple way to find the last match of a string in a larger log file, and send every line following it (inclusive) to another file? Example: grep -A222 ...
2
votes
4answers
4k views

remove white space before delimiter with sed

I have data of the following format that I want to input into LibreOffice calc data | num | num | num | num For some reason Libreoffice does not think the string "3214 " is a number by ...
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2answers
2k views

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
204 views

sed one-liner to delete word-medial spaces

I have a text file that consists of some N ORMAL E NGLISH W ORDS in all-caps. Unfortunately, these words all have a space between the first and following letters, which is not acceptable. I tried ...
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votes
3answers
814 views

Filtering paths to a specific depth

I'm using rsync and the flags -nPaAXz ~/ to check which files are going to be copied. This is far too verbose to make any sense of. How could I filter the output so I view the list of files/folders ...
2
votes
4answers
72 views

Substitute all occurrences of pattern with first matched group

I have to go from this: text match$something_here and match$xxx blablabla text match$something_else_here and match$xxx blablabla ... to this: text match$something_here and match$something_here ...
2
votes
1answer
668 views

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 ...
2
votes
2answers
149 views

regex - Searching for only character pairs

I have the following data from which I mean to extract only those lines which contain "bb" only. Not "b" or "bbb" or anything else just "bb". abb abbb aabbcc aabab abbbbc Now when I use the ...
2
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2answers
126 views

What is the regex to validate Linux users?

When adding a new user, how is the string validated? I suppose there is a regular expression. What is that regular expression?