Tagged Questions
Regular expressions are a means of matching a pattern of characters within a string.
-1
votes
1answer
31 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
vote
2answers
40 views
perl regex replacing globally when global not selected
I'm using Ubuntu 11.04 and wrote a small script that searches within text files for certain "tokens" and replaces with some a prewritten snippet from a template file of the same name.
The text files ...
2
votes
2answers
33 views
Grep 'OR' regex problem
I am trying to use grep with a regex to find lines in a file that match 1 of 2 possible strings. Here is my grep:
$ grep "^ID.*(ETS|FBS)" my_file.txt
The above grep returns no results. However if I ...
1
vote
1answer
17 views
What special characters does grep parse by default? [closed]
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 ...
6
votes
1answer
75 views
How do you save a complex regex for multiple reuse in sed?
In using sed, I often create rather complicated and intricate regexes that I need to match twice in a file. Is there a way for me to save this regex and just reference it twice?
Maybe something that ...
3
votes
3answers
66 views
What does . match?
In working with regular expressions, I have been told that a dot character . will match everything.
Except for newlines \n.
Are there any other exceptions? What about the NUL character \0, or the ...
3
votes
3answers
78 views
In a regular expression, which characters need escaping?
In general, which characters in a regular expression need escaping?
For example, the following is not syntactically correct:
echo '[]' | grep '[]'
grep: Unmatched [ or [^
This, however, is ...
2
votes
1answer
50 views
Substitute text with sed and keep part of the original text
I am trying to convert
<id>1</id>
<Name>ENTERPRISE RESOURCE PLANNING</Name>
to:
<column name="id">1</column>
<column name="Name">ENTERPRISE RESOURCE ...
2
votes
1answer
34 views
Renaming files to have lower case extensions with 'rename'
I'm trying to currently rename a large set of files and have been using quite kludgy methods to do so, such as:
rename 's:(.*)\.MOV:$1.mov:g' *.MOV
rename 's:(.*)\.JPG:$1.jpg:g' *.JPG
What I'd ...
1
vote
3answers
30 views
expr help - managing strings
I need to take text like this:
A234321=http://www.google..... a normal URL
And pull out only the URL, getting rid of the first part. I think I can use expr to do it, but I can't figure out the ...
3
votes
1answer
84 views
Why are capital letters included in a range of lower-case letters in an awk regex?
$ echo ABC | awk '$0 ~ /^[a-b]/'
ABC
$ echo ABC | awk '$0 ~ /^[a-a]/'
$ echo ABC | awk '$0 ~ /^a/'
$
You see. /[a-b]/ captures A, but /[a-a]/ or /a/ doesn't. Why?
3
votes
1answer
64 views
Is there a tool in linux that allows multi-line regex expressions?
I'm wanting to find the results of a multi-line regular expression in linux. I tried grep, but like most linux utilities it's line based.
Is there something similar that allows me to search across ...
1
vote
1answer
32 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
56 views
Regex : how to verify that there are 13 greek letters with an odd number of consonants
Another regex that I can't seem to crack :(
I tried with egrep '([qwrtzpsdfghjklxcvbnmy]{1})|([qwrtzpsdfghjklxcvbnmy]{3})|([qwrtzpsdfghjklxcvbnmy]{5})|([qwrtzpsdfghjklxcvbnmy]{7})' greek.txt
...
2
votes
2answers
53 views
Regex : match 2nd and 3rd character
I was doing some exercises on regular expressions, but I can't seem to be able to crack this one :
egrep in a file where the 2nd and 3rd character are the same.
I tried :
egrep '^..{2}' ...
