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

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grep for lines/files that contain exactly X chars

Here's the output of a grep command I ran: [user@localhost] : ~/Documents/challenge $ grep -i -e ".\{32\}" fileA fileB fileA:W0mMhUcRRnG8dcghE4qvk3JA9lGt8nDl fileB:observacion = new Observacion(); ...
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1answer
50 views

emacs dired regexp mark files beginning with

In Emacs Dired mode, I'd like to mark directories and files whose names begin with Addr but not files that contain Addr inside the name. I'm using RE-Builder to test my regular expressions and am ...
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2answers
75 views

Delete folders using regex

I would like to delete folders with specified regex, but I could not build a good regex. I have: /root /my-picture-2015 /my-picture-2015-1 /my-picture-2015-2 /my-picture-2015-1 /my-...
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5answers
254 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 ...
2
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1answer
48 views

How do I match the beginning of a line in a manpage?

When I do man zshbuiltins I typically want to search for a command. Suppose I'm looking for info on the alias command. I get a chunk of text like: : [ arg ... ] This command does ...
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3answers
154 views

Undo letterspacing with sed

I have a source text file containing text where some words are l e t t e r s p a c e d like the word "letterspaced" in this question (i.e., there is a space character between the letters of the word. ...
2
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1answer
65 views

Move up every other line to end of line containing character

I have run two xpath queries piped together to retrieve certain information. However the results came out formatted on separate lines while I want them to be on the same line. For example the lines ...
2
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1answer
279 views

regex usage in exim filtering

I'm trying to create an exim filter to block spam messages containing " 85% OFF" in the subject line. That's a blank space, then any two digits, then the percent sign, a blank space and the ...
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4answers
263 views

Delete everything before “/” on every line

I am trying to delete certain text that appears before / on every line. I have something like: testing.db.com/7fad416d-f2b3-4259-b98d-2449957a3123 testing.db.com/8a8589bf-49e3-4cd7-af15-...
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1answer
33 views

Wrap all lines with character sequence in vim

So basically I copy/pasted some code, and I need to prepend and append some more code to each line. Each line is a function call, and is getting added to a switch statement as it's own case. Right ...
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90 views

get values which only occur once in a vector

There is a vector of numbers I have which are in ascending order (it is called t8_) 2 7 8 9 11 15 34 91 91 92 94 The problem is that some numbers happen two times. I don't want to remove them, but ...
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3answers
744 views

How to replace text between two markers in a file with a section of text from another file?

Say I had a block of text in the ~/.bashrc: #~/.bashrc # ...some commands... # aliases alias suicide='sudo rm -rf /' # end aliases # other commands I wish to replace that block of text with some ...
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1answer
203 views

Remove the exact same matching lines with sed

I have this bash script: sed -i -r '/deb http\:\/\/httpredir\.debian\.org\/debian jessie main/d' /etc/apt/sources.list sed -i -r '/deb http\:\/\/httpredir\.debian\.org\/debian jessie\-updates main/d' ...
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3answers
229 views

Shell pattern matching and arithmetic operators (+ - * / %)

This looks so simple but it isn't: [[ "1234+5678" =~ [0-9]+(\s*(\-|\*)\s*[0-9]+)* ]] && echo $? returns a 0. However, it actually should not do that, as only minus (-) and multiplication (*) ...
2
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1answer
268 views

Match a number range with grep

I need to find all processes that have in their names a number between 100 and 200 inclusive. I tried ps -ef | grep xclock -bw '[1-2][0-9][0-9]' but that includes 299. How to suppress it and ...
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2answers
481 views

Extract just the hostname and port number from tnsnames.ora file

I would like to give a hostname, and get a port number in return. My tnsnames.ora file looks like: DELUCA = (DESCRIPTION = (ADDRESS = (COMMUNITY = TCP.world)(PROTOCOL = TCP)(Host = database....
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1answer
68 views

Find directory names with N occurences of a set of characters

Sorry in advance, I know there are hundreds of posts about find, but I genuinely don't understand what's happening here and haven't been able to find a definitive answer to this question: how to match ...
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157 views

Grep for regex in basename but return wholename

So say I have a list of files in a text file: ... /foo/barfoo /bar/foo/foobar /foobar/bar/foo ... I have a script that will search through this text file and, much like the locate command, I want ...
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3answers
52 views

match same lines [closed]

I've a file for which I need to know if it has entries which are the same The file contains entries like this: dn: cn=ccb2fa1a-6efb-4f29-b18b-72e226d76935,ou=Named,ou=Identities,ou=Active,o ...
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1answer
72 views

What does “\(\)” stand for in this command: grep(“-(mean|std)\(\)”, x[,2])

Need to know about the function of \(\) in grep("-(mean|std)\(\)", x[,2])
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83 views

Find all characters “[1-777])” at the beginning of the line

Pseudocommand perl -pe 'g/^[1-777])/g' data.txt where I try to all numbers at the beginning of a line with ")" following them etc 1), 67) and 777). Data where all question numbers should (etc 1), ...
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3answers
83 views

Match beginning of a line with something there?

I want to match the beginning of lines where the line contains something. Command in Perl/Sed 's/^.?/\section{}/g' but the problem here is that it replaces also the first character of sentences. ...
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1answer
851 views

Regex for crontab validation

I need to check in bash whether an entry into the crontab file is valid. Is there a crontab command switch? I can extract individual lines and try to control individual items through regex. But I ...
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4answers
2k views

How to use regex to match a pattern which does not have a specific string at the end

How to use a posix bre or a posix ere regex to match a word which does not have bak at the end. I want to do a ls | egrep '<regex>' to find all files which DO NOT have bak at the end of ...
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2answers
156 views

How to filter content between specific keywords using grep?

I got a bunch of files, and I want to find out the content between two tags st and et. if I use grep "st.*et" files, I will get these two tags involved in the result. Such as st Hello world! et. But I ...
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2answers
138 views

searching for the c++ in a string (regular expression)

I want to find if a string contains c++ in it (regular expression). what pattern should I use in grep function in R? This is my error: Error in grep(pattern = "c++", x = df[trow, "modeling"]) : ...
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1answer
45 views

How to integrate awk parameters in awk range pattern

I need to get something like this #Batch Job - AB1234 texts texts texts texts texts #-------- I used awk '/#Batch Job.*AB1234/,/#--.*/' filename and i went well. But then when I tried to ...
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2answers
370 views

UltraEdit - regular expressions replacement

I was trying many different combinations without success, at this point I would be really grateful for your help. I need to replace this end of the line multiple times (around 300) and it would be ...
2
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4answers
73 views

remove the content from the beginning to the first blank line

I'm trying to remove the content from the beginning of the text to the first blank line. --($:~)-- cat example.txt pedro pablo juan francisco emiliano martin So, I would delete: pedro pablo ...
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6answers
645 views

sed command to swap characters

My input file layout is: mm/dd/yyyy,hh:mm,other fields I need to format it as: yyyy-mm-dd hh:mm:00,other fields sample input: 01/02/1998,09:30,0.4571,0.4613,0.4529,0.4592,6042175 01/02/1998,09:45,...
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How to detect end of line with sed

I'm looking for a way to only execute replacement when the last character is a newline, using sed. For instance: lettersAtEndOfLine is replaced, but this is not: lettersWithCharacterAfter& ...
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5answers
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How to grep an xml block in an xml file using a keyword in ksh

I have a file Sample.xml which contains a lot of services inside it and the structure looks like this Notes: I cannot use any XML parser tool as I don't have permission , read only My xmllint ...
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1answer
202 views

How to parse through a .dat file and get patterns such as timestamps and file size of a .jar file declared inside

I want to compare the size and timestamp of the following jar files in separate directories. First data is fetched by: grep -Eo "[[:digit:]]+[[:space:]]+[[:digit:]]+.[[:digit:]]+.[[:digit:]]+[[:...
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1answer
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Why does this command remove more packages than I want it to?

When I run the following command: # apt-get purge unity-scopes-m* I expect it to delete the following packages: unity-scope-manpages unity-scope-musicstores unity-scope-musique Instead, it wants ...
0
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1answer
83 views

postfix: what does /.+/ in pcre do?

I'm rewriting all sender addresses to one address in Ppostfix. main.cf includes this line: sender_canonical_maps = pcre:/etc/postfix/canonical_sender The file canonical_sender looks like this: /.+...
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2answers
93 views

Insert “return 0” between all braces in a file?

I'm setting up a fairly large (~50 functions) test library in C++. I forgot that the functions have to return integers. I actually forgot to put a return type at all, how dumb is that? I added the int ...
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awk search for string containing forward slash in variable [duplicate]

I'm searching for a string in a massive XML file. Snip: <sv:node sv:name="notfound"> <sv:property sv:name="jcr:primaryType" sv:type="Name"> <sv:value>hst:component&...
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2answers
83 views

Search and replace with a regular expression in vi?

I would like to replace a string with regular expression that appears in multiple lines with the character "x": The problem is to replace words with the x in front that has an integer after the x, ...
4
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6answers
265 views

Append something to each list in a file

I have a file, lists.txt, that looks like this: // stuff at beginning of file var list1 = new Array(); i = 0; list1[i++] = 'a'; list1[i++] = 'b'; ... list1[i++] = 'z'; var list2 = new Array(); i = ...
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Interpreting regex wildcards with grep [duplicate]

This is a really simple question, but even after reading about wildcards/regex, I can't seem to grasp entirely what the differences between these commands are: grep . test.txt this one will look ...
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2answers
103 views

Regex for surrounding every word that contains & with $…$

I am thinking what is a robust approach for this. I try to match unsuccessfully by: [A-Za-z]*&[A-Za-z]* Which returns: so the mistake in \\&\hskip environment. How can you match ...
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2answers
77 views

How to do operation on individual matches in a full line

I have a Verilog line like this: if (i2_0&!(i2_1)) (posedge i0_0 => (o:1'b1))=(0, 0); How can I convert it to a line like: if (i2_0 == 1'b1 & i2_1 == 1'b0) (posedge i0_0 => (o:1'b1))=(0, 0); ...
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To Regex Pandoc Tables

Minimum Data to regex \documentclass{article} \begin{document} ------------------------------------------------------------- A B C D Header Aligned Aligned ...
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1k views

what is meant by “^$1” in shell script?

#!/bin/sh #emp3.sh: using if and else # if grep "^$1" /etc/passwd 2>dev/null then echo "pattern found - job over" else echo "pattern not found" fi in the above programme what is "^$1" and ...
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0answers
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Why does find not match repeat / quantifier expressions with emacs regular expressions? [duplicate]

I have a file 'abcd' in my current dir. Using find -regex '\.\/[a-d]\{4\}' gets me no results. While the regex works fine in emacs itself. find, however, does find my file when I add -regextype posix-...
4
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3answers
1k views

RegExp testing with ash shell (BusyBox)

I need to do a RegExp pattern test on a certain bit of user input. This is the pattern I need to test the value against. ^([a-z]{2,3})\-([a-z][a-z]*[0-9]*)\-(\d+)$ An example match would be: na-...
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2answers
672 views

How to match and replace an attribute value inside a tag

I am trying to replace the value of following node using sed command. <KeyValue key="EMPTY_SEARCH_CRITERIA" type="String" value="CS_CODE" comment="Configured empty search criteria."/> I am ...
0
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1answer
146 views

grep searching groups

I'm trying to learn to use grep groups, like sed \1\2\3, but have a problem. For example I filtering /etc/services file to separate all ports. What I do: ~$ grep -E '[0-9]{1,5}/(tcp|udp)' /etc/...
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1k views

How to replace multiple occurrences of a pattern with sed

I use the following command to remove surrounding spaces between array keys that are strings or integers in PHP files: sed -ri "s/\[ ([0-9]+|(\x27|\x22).*(\x27|\x22)) \]/[\1]/g" file.php I thought I ...
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1answer
174 views

Why can't I escape the braces “]” in sed?

Question: Why can't I escape the "]"? $ printf "*#$@~\!&*()[]\n" *#~\!&*()[] $ printf "*#$@~\!&*()[]\n" | sed 's/[*#$@~!&*()\[\]]//g' *#~\!&*() $