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

learn more… | top users | synonyms (1)

1
vote
1answer
203 views

Easy Regex on Apache Logs

I'm struggling to create a regex for Apache logs. It's for ignoreregex on Fail2ban. I'd really like to be able to put something like /house to catch all files in that directory or ...
1
vote
3answers
161 views

find with user variables

I am trying to call find with a few variables. So far I had this: DIRECTORY="./ " FILENAME=-regex" .*test.*" find $DIRECTORY $FILENAME Which works fine. If I change the filename to : ...
0
votes
5answers
2k views

(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 ...
0
votes
1answer
196 views

What does ^> mean in a grep pattern?

What does this command do? grep "<[^>]*>" inuux.xml What is searching for?
0
votes
2answers
1k views

Using grep to match only a match group in a regular expression?

I need to set my keyboard layout with setxkbmap before launching Wine games, as I use Dvorak for typing and this breaks every game's controls. What I'd like to do is simply write a script that grabs ...
0
votes
2answers
276 views

Why does this regex find a match for \x63 with a pattern [\80-\BF]

I am trying to filter valid/invalid UTF-8 bytes, but I get strange results from the following regex (which is intended to handle a 3 byte form of UTF-8). I have intended the pattern should not ...
0
votes
2answers
78 views

bash - reading user variable into bash script grep

I've tried every possible combination to get this bash script working. It's part of a larger script, and it basically prompts for a username (to check if it exists) and returns the appropriate ...
0
votes
1answer
378 views

Asking ls to only list files in a path that match a specific glob/regex

In Zsh: Is there a way to use ls to only list files and folders in the current directory that match a specific globbing or regex pattern? For example, say I have multiple files that start with the ...
0
votes
3answers
130 views

Regular Expression for finding double characters in Bash

I am looking for a regular expression that finds all occurences of double characters in a text, a listing, etc. on the command line (Bash). Main Question: Is there a simple way to look for sequences ...
0
votes
3answers
58 views

regex suggestion

echo "223255/12345678 " | grep '[0-9a-zA-Z/\-\?:\(\)\.,"\+]{1,34}' According to the regex, it can have any of 0-9 a-z A-Z / - ? : ( ) . , " + of upto 34 chars in any order. Am I ...
0
votes
1answer
93 views

Replacement in VIM with regular expression matched part unchanged

Suppose I want to append two digit numbers in my file with "some_thing". Like from this: 12 23 45 to 12_something 23_something 45_something How can I do this using regular expression ...
0
votes
1answer
47 views

How to ask for specific parameters with grep?

I need to look in /usr/share/dict/words for a 5-letter word that starts with d or D, followed by a lowercase vowel, and ends with s. I have tried everything but to no avail.
0
votes
1answer
49 views

Regex awk to Cisco Interface

I would like to know if have some Sed/Grep or Awk regex to parse Cisco interface section, with specific attribute, like bellow. Content of file.txt ! interface FastEthernet0/1 no ip unreachables ! ...
0
votes
1answer
45 views

Help with understanding a regular expression

I have this regular expression \\..\\{3\\}$ I want to understand how this expression works to match a string. My thought is that it matches any 8 characters at the end of the line. Is that how this ...
0
votes
2answers
100 views

regex, only the first occurence

I have a pipelined output from free -o -m | awk '{print $4}' I want take step by step two numbers the first and the second line. So i need two regexes. I tried with ^[0-9]{1,3}$ but this match all ...
0
votes
1answer
208 views

Egrep: contains and does not contain

egrep -i '12-12.*\swarning' log.file | cless The above will produce two lines with the date 12-12, followed by random characters, a white space, then Warning and more text. 2011-12-12 textetc ...
0
votes
1answer
141 views

python regex equivalent of kwrite [ ]+ and [0-9]+

I've never been good at regular expressions. When ever I read about them, I sort of get a headache, get up from my desk, and forget what I'm doing. Attention difficulties. But when I finally started ...
0
votes
1answer
495 views

Curl and grep html text

Is there a way to grep html text from a curl request and output grab the value that is between two html tags? More specifically the input value of a form?
0
votes
1answer
36 views

(e)grep and atomic grouping [comprehension question]

I am trying to understand the correct use of »atomic grouping« a.k.a. »independent subexpressions« a.k.a. »non-backtracking subpattern« [this are the terms I found ...
0
votes
1answer
26 views

Comment the if statement and the matching endif keyword

In vim, I can find the matching if statement and prepend the appropriate comment symbol. (e.g. %s/.alarm./#\0/g), but then I am left with dangling endifs that I have to find manually. I could simplify ...
0
votes
1answer
36 views

How to highlight the whole log-line in color with multitail

I'm trying to use multitail to tail logs with color highlights. I defined a custom color scheme in multitail.conf, something like this: colorscheme:my-color cs_re:red:^\[E cs_re:yellow:^\[W ...
0
votes
2answers
162 views

Difference in regular expression handling between Perl, Kikki, and Kodos

#!/usr/bin/perl $mystring = "[2004/04/13] The date of this article."; if($mystring =~ m/(\d+)/) { print "The first number is $1."; } Perl returns 2004, but Kiki and Kodos return /04/. Why ...
0
votes
2answers
94 views

what is “an invisible whitespace character that takes up space”

One can look up Unicode Characters with Regular Expressions. On Jan Goyvaerts website I found a RegExp whose meaning I don't understand : \p{Zs} or \p{Space_Separator}: a whitespace character that ...
0
votes
1answer
259 views

Remove a block of lines between two patterns [duplicate]

Possible Duplicate: Show only text between 2 matching pattern In a bash script using sed how can I remove a block of lines beginning with -pattern a- and ending with -pattern b- where the ...
0
votes
1answer
104 views

awk extended pattern matching (embedding pattern matching in actions for already matched strings) [closed]

I want handle strings of the form: PREFIX_TYPE_N,DATA So, does the *awk (gawk, mawk, nawk) support including pattern matching in the action for already matched string? Something like this (of ...
-1
votes
2answers
241 views

Meaning of asterisk (*) in grep

[USERNAME@host ~] echo -e 'prdxxx\ndadxxx' | grep "da*xxx" prdxxx dadxxx [USERNAME@host ~] echo $SHELL /bin/bash [USERNAME@host ~] dpkg -l | grep -iw bash ii bash ...
-1
votes
3answers
311 views

How to tell grep to match special character at beginning of each word [duplicate]

I have certain questions regarding grep. Why does the following command match '<Hello'? $ grep -E "\<H" test Hello World <Hello H<ello What needs to be done to match '<Hello' only? ...
-1
votes
1answer
255 views

How to “grep -v” private/broadcast IPv4 addresses?

time nmap -n -iR 0 -sL | cut -d " " -f 5 | egrep -v "^10.*|^172.[16\-32].*|^192.168.*|^[224\-255].*" > RANDOM-IPS.txt so the important part is: egrep -v ...
-1
votes
1answer
45 views

Doing regex in python [closed]

I had a directory "/pcap_test" which contains several log files. Each file has a pattern like: Pkt: 1 (358 bytes), LIFE: 1, App: itunes (INTO), State: TERMINATED, Stack: /ETH/IP/UDP/itunes, Error: ...
-2
votes
1answer
76 views

Commands with regex support? [closed]

What are they? I know vi grep equery

1 2 3 4 5