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

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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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(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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280 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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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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3answers
873 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, ...
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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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5answers
294 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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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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4answers
737 views

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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229 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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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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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= , classs= , marks=. Using grep "name=\|age=\|class=\|marks=" ...
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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 ...
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2answers
267 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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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
130 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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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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526 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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299 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
383 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
589 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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472 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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5answers
152 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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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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509 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 ...
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1answer
443 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
806 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 ...
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1answer
4k 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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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 ...
2
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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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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 ...
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1answer
218 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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3answers
895 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 ...
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2answers
100 views

How to escape correctly this word on vim?

I want to substitute this word ${ARRAY1[@]} with $1 on vim substitution command I did :%s:\$\{ARRAY1[\@]\}:\$1:g But give me error about number of repetition,i try also "" but doesn't work How to ...
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75 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 ...
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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 ...
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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 ...
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260 views

can regex capture groups be used in GNU find command?

With the GNU find command (GNU findutils 4.4.2), a regular expression can be used to search for files. For example: $ find pool -regextype posix-extended -regex ...
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2answers
123 views

Condition string matches reg.expression

So, in my script, I have to decide whether one of the parameters is a valid email address. I was trying, but it failed. if $maddr="^.$*\(@\)\(*\)\(.\)\(??*\)" then ... It's meant to mean: at least ...
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4answers
943 views

regex matching with “locate”

I'm trying to use the locate command to find files in my home folder, however whenever I try and run this I get no results: locate -i -l 4 --regexp '^\/home\/jack\/[A-Za-z0-9\/\ ]*(My.)*$' I've ...
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1answer
326 views

Counting consecutive repetitions of a specific character (e.g. ,)

Say I have a file with lines like the two following: foo,bar,,baz,xy foo,,bar,baz,xy,, I would like to count how many times I have ,, (two consecutive commas surrounded by any other character) in ...
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2answers
94 views

Does [[:space:]] work for sed patterns on all Linux distros?

Using [[:space:]] looks a little non-elegant and, quite frankly, Microsoft-ish for sed match patters. I was trying to extract "Last" out of "First Last" and either of the following worked: echo ...
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votes
4answers
8k views

Regular expression in Bash to validate IP-address

In my Python script i have a regular expression for searching IP-addresses like 0.0.0.0-255.255.255.255 in a file, it looks like this: ...
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2answers
841 views

Trouble getting regex to work with find

I'm having a lot of trouble getting find to work with regex flags. Im using egrep on its own to find a date pattern in a file, like this: egrep '[0-9]{4}-[0-9]{2}-[0-9]{2}' which will return dates ...
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1answer
848 views

How to Replace Path in Search field using VIM

I'm trying to replace this text in VIM Actual Path /home/omipenguin/Servers\ Information/systemscript.sh/sysinfo.txt with this new path /home/sysinfo I tried %s/\/home\/omipenguin\/Servers\ ...
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2answers
181 views

regular expressions with grep

I have this command right here: grep -B10 -A10 '14:14:50 {"channels":["/alerts/6979/new"],"data":"New alerts for unit 6979"}' mygateway.log Rather than searching for 14:14:50 I would like the 50 to ...
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2answers
395 views

Regex and piped commands with sed

I'm finding really hard to use sed command, plus I can't seem to find well written tutorials. Let me say that I worked with regular expression in other languages (Python, JavaScript, Java), so that ...
2
votes
1answer
243 views

grep all words with specified length, without letter x

So I am stuck here: grep -E '^....c...c...$' shows all words with the expr I need. Now from this words I only need the ones that don't have a x. Who can help me?
2
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2answers
586 views

AWK match string, not Regex

How do I match a string with AWK? Say I have the string [(*.+ it should only match strings containing the string [(*.+. The string is entered by the user, so if you know a cli utility that can ...
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4answers
6k views

How can I find all files in a folder that contain a match of a regular expression in the file name?

I'd like to find all of the files in my home folder on Linux (Ubuntu, in this case) that contain a match a particular regular expression. Is there a simple Unix command that I can use in order to do ...