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

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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
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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. ...
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2answers
410 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 ...
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3answers
973 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 ...
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4answers
4k 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 ...
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2answers
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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
309 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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1answer
87 views

Search file name within file

Someone put a lot of malicious code onto every single wordpress instance on my server. For the second time. (At least) Every js file has been modified. There is a pattern though, the code always looks ...
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2answers
65 views

Replace only on the first matching line with sed

Using BSD sed (no GNU extensions), how can I perform an operation similar to the example provided below, but where instead of the line number, the replacement is performed on the first line in which a ...
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0answers
191 views

What types of regex DO support (e.g.) negative lookbehind?

Bash on GNU: I am using a collection of find commands, most of which employ -regex to do their matching. Each time I try a different feature in my regex I have to cycle through the values for ...
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0answers
134 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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4answers
631 views

Why does the grep command ignore the period in the search string?

The command that I am using: find . -type f -name "*.sql" -exec grep -i -l 'schema_name.' {} + What I want to search is all the files which contain schema_name.. But the find command is ignoring ...
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5answers
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(Mac Terminal) sed to parse JSON … what am I doing wrong?

In Mac Terminal, I'm trying to parse the "name" out of this JSON response: {"created_at":"2012-08-27T20:04:27Z","deleted_at":null,"id":21462840,"item_type":"video","name":"CastingBy-v12 ...
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4answers
328 views

Replace regex match with string containing match

I have a file with text as Afghanistan=+93 Albania=+355 Algeria=+213 American Samoa=+1 Andorra=+376 Angola=+244 It has all the country list and its dialing code. I want to replace: ...
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5answers
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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 ...
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5answers
538 views

ls | grep works doesn't work with ls --color

I'm trying to list all hidden dirs with the following command ls -lhAF1 | grep -E '^d.*[0-9]{2}:[0-9]{2} \.' which works perfectly fine Explanation for Regex: I'm trying to get all rows that ...
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5answers
324 views

Duplicate lines and make them unique?

I have the following structure of text lines: 3923 001 L05 LV,L05 RM 3923 002 L12 RA,L12 LA 3923 003 I06 ALL 3923 004 G04 RV,Z09 ALL but i would need this: 3923 001 L05 LV 3923 001 ...
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3answers
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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, ...
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3answers
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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 ...
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6answers
333 views

Extracting IP address from a text and store it in a variable

I have a text file named abd shown below. 48878 128.206.6.136 34782 128.206.6.137 12817 23.234.22.106 I want to extract only IP address from the text and store it in a variable and use for other ...
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5answers
569 views

Replace characters in user part of email address

I have a list that looks like this: user-name@domain.example user.name@domain.example user_name@domain.example ... I would like to replace any occurence of a dot in the username part. So that: ...
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4answers
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Match multiple regular expressions from a single file using awk

I'm trying to parse a HTML file using shell scripting. There are 4 different regular expressions that i need to catch: name= , age= , class= , marks=. Using grep "name=\|age=\|class=\|marks=" ...
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2answers
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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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1answer
311 views

shell: The =~ operator does not work as expected

Consider the following script: #! /bin/bash line="confusing" if [[ $line =~ [[:lower:]]* ]] then echo "matches!" else echo "does not match." fi While the above produce the expected ...
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4answers
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SED command not replacing (working regex)

I'm trying to replace in one of my projects all mysql to mysqli, with their parameters. To do so, I'm searching for all files with mysql in my folder recursively and replacing it with mysqli. Ex: ...
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2answers
234 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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158 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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2answers
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Differing outputs of the commands “ls .*” and “ls *.”

The command ls .* when run gives as output the following : All the files in the current directory starting with a . (hidden files) All the files in the hidden directories present in the ...
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4answers
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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 ...
2
votes
2answers
141 views

Delete row if two patterns are found in the same line

I'd like to delete a line from a text file (input.txt) if two patterns (string1and string2) are found on the same row, using sed. I'm trying: sed -i "/\b\(string1\|string2\)\b/d" input.txt, but ...
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extract url between 2 strings in a file

I have a file in which each line is like this "372"^""^"2015-09-03 06:59:44.475"^"NEW"^"N/A"^""^0^"105592"^"https://example-url.com"^"example-domain < MEN'S ULTRA < UltraSeriesViewAll ...
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2answers
463 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: ...
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2answers
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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 ...
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3answers
134 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}}, ...
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Regular expression problem(s) in Bash: [^negate] doesn't seem to work

When I execute ls /directory | grep '[^term]' in Bash I get a regular listing, as if the grep command is ignored somehow. I tried the same thing with egrep, I tried to use it with double and single ...
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1answer
622 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) ...
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413 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, ...
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3answers
410 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 ...
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2answers
733 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 ...
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2answers
528 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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3answers
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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 ...
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votes
3answers
168 views

sed regular expression behaving differently than in vim and perl?

Here's a sample 'test.txt' abcdX1yad45das abcdX2fad45das abcdX3had45das abcdX4wad45das abcdX5mad45das sample desired output: X1yad X2fad X3had X4wad X5mad I could get it working in vim with: :% ...
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2answers
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vim find and replace around a string

In VIM, if, for example, I have the text http://a.com http://b.com is it possible to find all lines (the whole line) and replace it with something before and after it, such as: <a ...
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5answers
212 views

Testing if files start with certain letters and contain no special character except for period at end next to file extension in a shell script

I have a shell script that runs a for loop to execute a command on multiple text files in a folder. I want to test if these files' names start with a specific set of letters (NA for instance), and ...
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2answers
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Extract substrings from each line. These substrings are in comma separated, “name=value” format

I have lines in a file that are comma separated. There are no column headers, it's mostly comma separated 'name=value' pairs. Here is some test data: ...
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3answers
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grep to find words with all vowels

Using grep -E and regular expressions I need to find words containing all of a group of characters in no particular order. For instance a word containing all vowels (aeiou) however the vowels can ...
2
votes
1answer
637 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 ...
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3answers
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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 ...
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2answers
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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 ...
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4answers
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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 ...