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

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3
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189 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
536 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
103 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
52 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"]) : ...
0
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1answer
39 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
79 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
67 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
377 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 ...
0
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3answers
243 views

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& ...
0
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5answers
268 views

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 ...
0
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1answer
64 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 ...
2
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1answer
33 views

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
36 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: ...
2
votes
2answers
50 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 ...
0
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0answers
34 views

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"> ...
0
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2answers
56 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
200 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
47 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
63 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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2answers
42 views

To Regex Pandoc Tables

Minimum Data to regex \documentclass{article} \begin{document} ------------------------------------------------------------- A B C D Header Aligned Aligned ...
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1answer
217 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 ...
2
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0answers
18 views

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 ...
4
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3answers
341 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: ...
0
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2answers
91 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
53 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)' ...
0
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1answer
170 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 ...
6
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1answer
152 views

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

Question: Why can't I escape the "]"? $ printf "*#$@~\!&*()[]\n" *#~\!&*()[] $ printf "*#$@~\!&*()[]\n" | sed 's/[*#$@~!&*()\[\]]//g' *#~\!&*() $
2
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2answers
58 views

Can't get GNU grep 2.12 to handle LF character in regex expression

I've been at it for over an hour, but can't find why it's not working. I'm searching an HTML document for "\nSome text". Simple enough. But he following commands won't work: grep -Po ...
0
votes
1answer
67 views

Use sed to only replace namespace in an element that has a parent element with a given attribute value

I want to replace the namespace in an xml file using sed (I've given up trying to do it from ant, where it is required). The main issue is that that there is a repeating list of elements - not all of ...
2
votes
1answer
30 views

Seeing all regex matches in a file in Bash

I'm in bash and I have a file, I want to find all matches of a regex in it and have them printed. How do I do that? Followup: Assume I want to print only unique matches, i.e. if a match appears ...
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1answer
76 views

Pattern matching inside awk

I intend to modify the output of ls -la to display the output of file command. The below command works well for the purpose find /opt -type f | xargs ls -let | awk 'BEGIN { OFS="\t" } { sprintf("file ...
2
votes
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 ...
2
votes
2answers
140 views

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
537 views

How to use [\w]+ in regular expression in sed?

I am on Windows, but I guess my question is still rightly placed here. C:\Users\User>grep --version GNU grep 2.6.3 C:\Users\User>sed --version GNU sed version 4.2.1 I noticed that the ...
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2answers
78 views

Delete text from a file using regular expressions

I have lots of text in a file. I want to delete all text that are between symbols === and <!!!>. E.g. Text ===some comments<!!!> lala ===aaa<!!!>" should be Text lala after running ...
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3answers
60 views

What characters should I escape while modifying a file using sed? [duplicate]

I am using the following sed command(with word boundary): sed "7 s/\<<Filevalue=.*/>\>/<Filevalue="true"/>/" < config.xml And I am getting this error: sed: command garbled: 7 ...
0
votes
3answers
80 views

To grep version number from Wordpress plugin folder

What will be grep regex to extract version number like Version: 3.1.5 * Version: 3.1.5 Will output 3.1.5 But It should not catch likes MIME-Version: 1.0\n Here is my grep command grep ...
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2answers
340 views

sed: problem while replacing string using wildcard

I am trying to replace a string using the following command: sed -e "s/\<$5\>/$6/g" "$2/$1" > "$4/$3" $5-> "hostname=*" $6-> "hostname=int1" $2/$1-> "source file path" $4/$3-> ...
0
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3answers
30 views

To improve this regex about digit separation

Code m/([+-]?\d+\.\d+)[\s\t]+([+-]?\d+\.\d+)/ Data 22.585698 3601.767090 D:\measurements\LabCourse_2015\6\90deg\image0001_23_mT.png 20.051883 3580.268555 ...
0
votes
1answer
56 views

Filtering Log Output on Separate Lines

I did a recursive grep in a directory to find all files that would match as follows grep -ER "match_string1|match_string2" /path/to/dir/ What I get as output is: ...
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1answer
385 views

nginx location regex with proxypass

I am quite new to nginx so excuse me in advance if i am asking something obvious. What i am trying to do is to proxypass to another server a request that comes to my nginx server in the form of: ...
1
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1answer
75 views

How to write a regex to look for strings with fixed length with at least one occurrence of a character

I've been doing some reading on regular expressions and thought I had everything covered, until recently. I've had to filter out all strings of length 5 which end with the letter t and contain at ...
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0answers
33 views

Regex for a non-fixed pattern

I am trying to come up with the right regex (compatible with python) that would match a file that contained sample input as follows: On the third day of Christmas my true love sent to me: three ...
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votes
4answers
213 views

Extracting subset of lines of a file based on regex for first & last line

I have a large text file and I only want to look at some of the lines. The first line I want matches a regex R, and when the line matches the regex S, I don't care about that line, or any following ...
5
votes
1answer
108 views

How to tell “grep -w” what characters make up “words”?

$ printf 'asf .test. afd\nasaf foo-test asfdads\n' asf .test. afd asaf foo-test asfdads $ printf 'asf .test. afd\nasaf foo-test asfdads\n' | grep -w test asf .test. afd asaf foo-test asfdads ...
13
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6answers
502 views

/bin/dash: check whether $1 is a number

What would be the best way to check whether $1 is an integer in /bin/dash ? In bash, I could do: [[ $1 =~ ^([0-9]+)$ ]] But that does not seem to be POSIX compliant and dash does not support that
3
votes
1answer
41 views

Find repository names from gitolite info output

How do I extract the names from the gitolite info command output, for further piping into a script? I'm writing a migration script to migrate all my repositories from gitolite to a Gitlab server. ...
2
votes
1answer
48 views

grep with regular expression

I want to match all the lines that are of the below pattern in a file using grep. Abc::xyz() [18-Feb-15 12:09:16] I came up with below regex with grep , but it is not returning match. Please help ...
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votes
4answers
434 views

How do I extract parts of a string to variables?

I have a line from some file like this: attempting to create a 512^3 level (with Dirichlet BC) using a 16^3 grid of 32^3 boxes and 800 tasks... I want to extract the 512^3, 16^3, 32^3 and 800 four ...