I try to use paramiko to list all TCP ports used on a compute. I found a good bash command here:
netstat -ant | sed -e '/^tcp/ !d' -e 's/^[^ ]* *[^ ]* *[^ ]* *.*[\.:]\([0-9]*\) .*$/\1/' | sort -g | uniq
This command works perfectly when I directly enter it in putty. However, when use it with paramiko, no output is shown.
Here is the sample code:
import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(host, username='demo', password='password')
command = "netstat -ant | sed -e '/^tcp/ !d' -e 's/^[^ ]* *[^ ]* *[^ ]* *.*[\.:]\([0-9]*\) .*$/\1/' | sort -g | uniq"
stdin, stdout, stderr = ssh.exec_command(command)
print stdout.read()
If I change the command as follow, the stdout do show the result, but this is not what I want. So I guess this is probably a regular expression issue with paramiko. Any idea?
command = "netstat -ant | sed -e '/^tcp/ !d'"
'\1' is same as '\x01'. You should escape \1.
>>> '\1'
'\x01'
>>> print '\1'
>>> '\\1'
'\\1'
>>> print '\\1'
\1
>>> r'\1'
'\\1'
>>> print r'\1'
\1
Using raw string(r'...') solve your problem:
command = r"netstat -ant | sed -e '/^tcp/ !d' -e 's/^[^ ]* *[^ ]* *[^ ]* *.*[\.:]\([0-9]*\) .*$/\1/' | sort -g | uniq"
Related
I have some key value pair arguments. I need to print them as is.
Example.
echo $X
(a=b) (c=d) (e=f)
echo "$X" | sed -E 's/([a-zA-Z0-9_]*=[a-zA-Z0-9_]*)/match/1'
echo "$X" | sed -E 's/([a-zA-Z0-9_]*=[a-zA-Z0-9_]*)/\1/1'
echo "$X" | sed -E 's/([a-zA-Z0-9_]*=[a-zA-Z0-9_]*)/\1/2'
echo "$X" | sed -E 's/([a-zA-Z0-9_]*=[a-zA-Z0-9_]*)/\1/3'
Post the above expresion, I wanted to print matching groups one by one. using .* in pattern matching is greedy and is printing either first or last matching groups only. How can I print any matching group in this way.
Here is my expected output.
a=b
c=d
e=f
This grep one-liner will do:
grep -o '[^(]*=[^)]*'
example:
kent$ grep -o '[^(]*=[^)]*' <<<'(a=b) (c=d) (e=f)'
a=b
c=d
e=f
Replace ) ( with a newline and remove the remaining parentheses.
echo "$X" | sed 's/) (/\n/g;s/[()]//g'
To print the $nth line, you can pipe the output to
sed -n "$n p"
How do I grep strings in between nested brackets using bash? Is it possible without the use of loops? For example, if I have a string like:
[[TargetString1:SomethingIDontWantAfterColon[[TargetString2]]]]
I wish to grep only the two target strings inside the [[]]:
TargetString1
TargetString2
I tried the following command which cannot get TargetString2
grep -o -P '(?<=\[\[).*(?=\]\])'|cut -d ':' -f1
With GNU's grep P option:
grep -oP "(?<=\[\[)[\w\s]+"
The regex will match a sequence of word characters (\w+) when followed by two brackets ([[). This works for your sample string, but will not work for more complicated constructs like:
[[[[TargetString1]]TargetString2:SomethingIDontWantAfterColon[[TargetString3]]]]
where only TargetString1 and TargetString3 are matched.
To extract from nested [[]] brackets, you can use sed
#!/bin/bash
str="[[TargetString1:SomethingIDontWantAfterColon[[TargetString2]]]]"
echo $str | grep -o -P '(?<=\[\[).*(?=\]\])'|cut -d ':' -f1
echo $str | sed 's/.*\[\([^]]*\)\].*/\1/g' #which works only if string exsit between []
Output:
TargetString1
TargetString2
You can use grep regex grep -Eo '\[\[\w+' | sed 's/\[\[//g' for doing this
[root#localhost ~]# echo "[[TargetString1:SomethingIDontWantAfterColon[[TargetString2]]]]" | grep -Eo '\[\[\w+' | sed 's/\[\[//g'
TargetString1
TargetString2
[root#localhost ~]#
I'm trying to get a pattern over multiple lines. I would like to ensure the line I'm looking for ends in \r\n and that there is specific text that comes after it at some point. The two problems I've had are I often get unmatched parenthesis in groupings or I get a positive match when there is none. Here are two simple examples.
echo -e -n "ab\r\ncd" | grep -U -c -z -E $'(\r\n)+.*TEST'
grep: Unmatched ( or \(
What exactly is unmatched there? I don't get it.
echo -e -n "ab\r\ncd" | grep -U -c -z -E $'\r\n.*TEST'
1
There is no TEST in the string, so why does this return a count of 1 for matches?
I'm using grep (GNU grep) 2.16 on Ubuntu 14. Thanks
Instead of -E you can use -P for PCRE support in gnu grep to use advanced regex like this:
echo -ne "ab\r\ncd" | ggrep -UczP '\r\n.*TEST'
0
echo -ne "ab\r\ncd" | ggrep -UczP '\r\n.*cd'
1
grep -E matches only in single line input.
I wanted to extract 12 from a text like "abc_12_1". I am trying like this
echo "abc_12_1" | grep -Eo '[a-zA-Z]+_[0-9]+_1'
abc_12_1
But I am not able to select the digit after first _ in string, the output of above command is whole string. I am looking for some alternative in grep which I have in following Perl pattern matching.
perl -e '"abc_55_1" =~ m/[a-zA-Z]+_([0-9]+)_1/ ; print $1'
55
Is it possible with grep?
Using perl:
$ echo "abc_12_1" | perl -lne 'print /_(\d+)_/'
12
or grep:
$ echo "abc_12_1" | grep -oP '(?<=_)\d+(?=_)'
12
You could use cut:
cut -d_ -f2 <<< "abc_12_1"
Using grep:
grep -oP '(?<=_).*?(?=_)' <<< "abc_12_1"
Both would yield 12.
One way is to use awk
echo "abc_12_1" | awk -F_ '{print $2}'
12
Or grep
echo "abc_12_1" | grep -o "[0-9][0-9]"
12
Using grep with extended regex
grep -oE "[0-9]{2}" # Get only hits with two digits
grep -oE "[0-9]{2,}" # Get hits with two or more digits
I want to extract the value pair from a key-value pair syntax but I can not.
Example I tried:
echo employee_id=1234 | sed 's/employee_id=\([0-9]+\)/\1/g'
But this gives employee_id=1234 and not 1234 which is actually the capture group.
What am I doing wrong here? I also tried:
echo employee_id=1234| egrep -o employee_id=([0-9]+)
but no success.
1. Use grep -Eo: (as egrep is deprecated)
echo 'employee_id=1234' | grep -Eo '[0-9]+'
1234
2. using grep -oP (PCRE):
echo 'employee_id=1234' | grep -oP 'employee_id=\K([0-9]+)'
1234
3. Using sed:
echo 'employee_id=1234' | sed 's/^.*employee_id=\([0-9][0-9]*\).*$/\1/'
1234
To expand on anubhava's answer number 2, the general pattern to have grep return only the capture group is:
$ regex="$precedes_regex\K($capture_regex)(?=$follows_regex)"
$ echo $some_string | grep -oP "$regex"
so
# matches and returns b
$ echo "abc" | grep -oP "a\K(b)(?=c)"
b
# no match
$ echo "abc" | grep -oP "z\K(b)(?=c)"
# no match
$ echo "abc" | grep -oP "a\K(b)(?=d)"
Using awk
echo 'employee_id=1234' | awk -F= '{print $2}'
1234
use sed -E for extended regex
echo employee_id=1234 | sed -E 's/employee_id=([0-9]+)/\1/g'
You are specifically asking for sed, but in case you may use something else - any POSIX-compliant shell can do parameter expansion which doesn't require a fork/subshell:
foo='employee_id=1234'
var=${foo%%=*}
value=${foo#*=}
$ echo "var=${var} value=${value}"
var=employee_id value=1234