Regular expressions are a means of matching a pattern of characters within a string.
2
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1answer
475 views
Escaping of meta characters in basic/extended posix regex strings in grep
Is it possible to escape all meta characters of a string inside a variable before passing it to grep? I know similar question has been asked before on SE
(here) and also a good explanation here, but I ...
2
votes
1answer
759 views
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.
...
2
votes
2answers
368 views
lookbehind and using it with grep in Vi?
Trying to get into Vi (not Vim), after learning Vim.
Vim has a lookabehind like /\(Not this\)\@<!$, how to do it in Vi?
If I want to search recurvively down directory in Vim, I could do :vimgrep ...
2
votes
2answers
328 views
Regex for phrase matching with case statement in ksh
I am trying to start or stop a service on AIX in ksh.
I am trying to start to build in fool proofing for checking things like if the services is already down, etc.
Here is my script
#!/bin/ksh
...
2
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2answers
216 views
Regular expressions with ExpectJ
I've been used the ExpectJ Java library to automate some jobs on a Linux server, however now I need to automate a job that sends a different text response for each execution. Here is the output:
Last ...
1
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3answers
57 views
Check some property for every line of a file
I have several (427 to be precise) text files with a million lines each containing 31 numbers separated be spaces (possible double spaces). However there might be some data corruption and there may be ...
1
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3answers
619 views
Print lines where first field has only four characters using regex in awk?
John Goldenrod:(916) 348-4278:250:100:175
Chet Main:(510) 548-5258:50:95:135
Tom Savage:(408) 926-3456:250:168:200
Elizabeth Stachelin:(916) 440-1763:175:75:300
output should contain the lines ...
1
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3answers
195 views
grep equivalent of the kwrite regex [A-Z][A-Z]+
So, it took me ages, but I finally learned to think in terms of regular expressions, thanks to using them in kwrite.
But I still don't know how to translate that knowledge to grep. I love my grep, ...
1
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1answer
482 views
Difficulty making a regular expression to find at least 2 occurrences of a character in a file
I have a file containing random codes. Each code has ten characters in it, and I am trying to grep codes in the file that have at least 2 occurrences of a character. I am doing this:
grep DD* ...
1
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2answers
132 views
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 ...
1
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3answers
168 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 ...
1
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2answers
288 views
Weird zsh grep -P behaviour
I connect to server with PuTTY from Windows.
I have a long yet not touched (I suppose) by hands of local admin config:
$ cat /opt/jira/.subversion/config
...
### must be enabled, which is ...
1
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1answer
154 views
What does this egrep command do?
What does this egrep command do?
egrep '[^A-M][0-9]+' /etc/passwd
So far I think it searches for any file in /etc/passwd that starts with A-M and includes the number(s) 0-9. Is that right?
1
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3answers
88 views
Trying to remove all ids from an HTML file with grep
I'm trying to remove all id=" "s from an .html file but I'm not sure where I am going wrong. I tried using regular expressions but all I am getting is the .html file rendering in my Ubuntu terminal.
...
1
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2answers
83 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 ...
1
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1answer
47 views
Regular expressions help
what the different between these two regex expression ?
AB\{4\} and (AB)\{4\}
for the first expression I think that it repeat B 4 times, then for second expression it
repeats AB 4 times. When I ...
1
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1answer
214 views
Using grep command and backreferencing
This is a pretty basic question, but I can't get my head around it. I'm learning Linux and one of the questions i've been given is;
*The word sentimentalment includes the same three characters ...
1
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2answers
115 views
Match a simple Regex
I need to match this: (tt\d{1,10}) in a file with the file ending txt.
I have tried grep and ack-grep but without results.
ack-grep -G \.txt$ -g "(tt\d{1,10})"
1
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2answers
256 views
How to find and replace files contents that match a pattern?
Suppose we have a folder named Project.
I would like find each file in the folder that contains the pattern &$
at the function call.
For example should replace:
AnyFunction(&$arg);
with
...
1
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3answers
889 views
sed pattern matching
I recently asked someone at work about how to take the output of ipcs -qa and make it space delimited, so I can parse it/store it in the database for monitoring. He gave me this:
ipcs -qa | sed 's/ [ ...
1
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2answers
1k views
Find all lines in a file with a certain character at a certain position
I have a lab question asking me to use grep with a regex pattern to match every word where the third letter from the beginning of the line is an "a" and save it with a redirect. How can I do that?
1
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2answers
278 views
pattern search and display the last occuring pattern?
I have a log file containing startup and shutdown times for everday.
I want to see the last pattern pattern for startup and shutdown(which is located at the end of the file being updated everyday).
...
1
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2answers
143 views
Pattern matching from the input arguments
we're trying to enhance the scripts.
Users will pass some arguments and part of the arguments will have 5.0.3 For an example the input argument would be like Jboss5.0.3GA. Since it ( Jboss5.0.3GA ) ...
1
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3answers
257 views
Compacting `find` name patterns
I am using
find . -name '*.[cCHh][cC]' -exec grep -nHr "$1" {} ';'
find . -name '*.[cCHh]' -exec grep -nHr "$1" {} ';'
to search for a string in all files ending with .c, .C, .h, .H, .cc and .CC ...
1
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4answers
333 views
Stripping all vowels but the first from a set of strings
I have a string comprised of multiple substrings, separated by underscores. For example: AbcdAEfd_hEgdgE_AbAAAAA. I need to remove all vowels except the first from each substring. So:
AbcdAEfd -> ...
1
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2answers
160 views
How do I generate a list of the characters occurring before a certain character only in lines that contain another certain character using regex?
I know that's super confusing (total noob-sorry!). To clarify, I have a text file that looks like this:
407-OL?
408-2-OL?
408-OL?
418-het?
420-1 and 2- OL?
429-2-left unscored?
430-2-left both ...
1
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2answers
156 views
Match neither regex
I have a Bash script which installs a customised JBoss. The name of the JBoss instance is checked against a regular expression to make sure that the name is valid:
if [[ ! $1 =~ $instanceNameRegex ...
1
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4answers
802 views
Processing control characters
I have a log file which contains a bunch of non visible control characters such as hex \u0003.
I would like to replace this using something like SED, but can't get the first part of the regex to ...
1
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3answers
120 views
Why is this Bash command using regex not replacing my brackets?
I have this command to go through all my files in my Music directory, and all subdirectories, and replace any square brackets in the file name with rounded brackets:
find /home/Music/ -depth -name "* ...
1
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4answers
335 views
Replace text between brackets
I'm using awk '{ gsub(/BAR|WIBBLE/, "FOO"); print }' to replace text in data like:
SOMETHING [BAR, WIBBLE]
SOMETHING [BAR]
This gives the desired result of:
SOMETHING [FOO, FOO]
SOMETHING [FOO]
...
1
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4answers
1k views
Replacing XML entity values with positive lookaround
I'm trying to do some pretty simple sedding of a file:
sed 's:(?<=<Type>)default(?=</Type>):super:' < myfile.xml
The concept's pretty simple, using positive lookaround, find the ...
1
vote
2answers
34 views
Trimming one part if equal to another part?
I use an e-mail quote attribution string like this:
On dd mmm yyyy hh:mm +hhmm, from info@example.org (Example Dot Org):
where info@example.org is the sender's e-mail address and Example Dot Org is ...
1
vote
1answer
60 views
Confused about word boundary
I have been researching this a lot, but I am still not clear on it. What does word boundary mean? What does it do?
So, for example, could someone explain this command to me please?
egrep ...
1
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2answers
100 views
grep: invalid content of \{\}
Here's the command :
grep '\(2\)[[:digit:]]\{\1\}' numbers
What I want is to match exactly 2 digits after the digit '2', 3 digits if I change the digit '2' to '3' in my expression, 4 digits if ...
...
1
vote
3answers
227 views
Find files in multiple folder names
I am trying to list all the files from dir1, dir2, dir3 and dir4 which might be anywhere in as a sub directory of my cwd using the find command. I tried the following with no success:
find . -type f ...
1
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2answers
135 views
How can I find matches with sed (or similar) for configuration parameters?
I'm pretty good at using php's preg_match (and similar) commands, and I'm also pretty good with regular expressions, but I don't do very well with sed.
I have two shell scripts I'm working on and I'd ...
1
vote
1answer
44 views
cclive: what kind of regexes are allowed?
Is there a place where I can look, what kind of regexes I can use with the --tr option from cclive?
1
vote
1answer
621 views
Match one part of a regular expression in a Kwrite find-and-replace regex
Among the joys of KDE, Kwrite is surely noteworthy. Having regular expression support built in by default into text editor is probably one of the top 10 best ideas of all time. Since I often need to ...
1
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2answers
204 views
How can I match this text in awk, printing line numbers for matches?
I have a text file thousands (roughly 148,000 lines long) that consists of a lot of sequences like this:
b 29.
b 52.
c 84.
c 83.
c 94.
c 93.
c 61.
b 38.
c 81.
c 92.
c 28.
c 37.
c 27.
... and since ...
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2answers
460 views
How to treat a file as a single line with grep to apply a regexp search pattern?
I want to match everything that is between some lines with regexp but not this that match the start and the end. This sound to me as positive lookbehind and positive lookahead
start text
bla ...
1
vote
1answer
380 views
reference problem in using sed
I'm trying to use sed command to find/replace a pattern in file.
It gives:
sed: -e expression #1, char 27: invalid reference \1 on `s' command's RHS
My command is:
sed ...
1
vote
1answer
199 views
Regex : all greek letters with 5 unique letters (meaning that each letter only appears once)
Another one I can't seem to solve : all greek letters with 5 unique letters (meaning that each letter only appears once).
my solution :
egrep '(.)([^/1])([^/1/2])([^/1/2/3])([^/1/2/3/4])' greek.txt
...
1
vote
1answer
34 views
Matching hexadecimals with gawk
I have a binary file with the following content (printed in hexadecimal):
$ xxd -p virus.com
5669727573b440bb0100b90500ba0000cd21
I can match the first 5 letters (which are the alphanumeric string ...
1
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2answers
51 views
linux + match IP ADDRESS with 3 octets or with 4 octets
how to match IP address with 4 octets or with 3 octets in one command?
target - match xxx.xxx.xxx or xxx.xxx.xxx.xxx ( syntax should fit for Linux and Solaris )
how to merge the following commands ...
1
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3answers
119 views
Recursively edit files based on parent directory's name
I'm facing an issue I'm not quite sure how to overcome. I have a large directory with hundreds of folders, all following the naming scheme "a_b_x", with x being a random word. In every one of these ...
1
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1answer
447 views
Regular expression how to get value in shell script?
I have to write a shell script to get value from a string .. something like that :
string="abcdef" pathName
How can I use "grep" command with the use of regular expression to get "pathName" ? Thank ...
1
vote
1answer
275 views
Multiply certain numbers in a text -file by certain constant
I want an alternative solution to this jQuery hack, tasting a bit reinventing the wheel -- look I am sure I could do this with some one-liner using basic *ix tools. Look much easier and ...
1
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1answer
107 views
What special characters does grep parse by default? [duplicate]
Possible Duplicate:
In a regular expression, which characters need escaping?
I know there is the -E flag which treats the "search term" as a regular expression. However, it seems that even ...
1
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1answer
164 views
How to match group 1 in a regex followed by a 0 rather than matching group 10
In regex plugin of gedit, I use a regex to match/search and another for substitution. In the matching regex, I only have one group. In the substitution regex, I use \1 to refer to the group, and I ...
1
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2answers
119 views
In-place substitution for lines matching some pattern in a given set of files
Following on from my previous question:
Remove slashes/parent paths from filenames inside CSS and Javascript content
I arrived at the following command which replaces any filenames in these ...
