My script like this:
#!/bin/env bash
monitor_sock_raw1=socket,id=hmqmondev,port=55919,host=127.0.0.1,nodelay,server,nowait
msock=${monitor_sock_raw1##,port=}
msock=${msock%%,host=}
echo $msock
I expect get '55919', but the result is:
socket,id=hmqmondev,port=55919,host=127.0.0.1,nodelay,server,nowait
Why and how to fix this bug?
For a simple requirement like this, bash supports a regex (See bash ERE support) approach using the ~ operator which you can use it to match the port string and match the digits after it.
#!/bin/env bash
var='monitor_sock_raw1=socket,id=hmqmondev,port=55919,host=127.0.0.1,nodelay'
if [[ $var =~ ^.*port=([[:digit:]]+).*$ ]]; then
printf "%s\n" "${BASH_REMATCH[1]}"
fi
The captured group from the regex is stored in the array BASH_REMATCH from which the first element after index 0 i.e. index 1 contains the value of 1st captured group.
RegEx Demo
You need to add wildcards or the patterns wont match. The pattern needs to match the whole start or end of the text.
msock=${monitor_sock_raw1##*,port=}
msock=${msock%%,host=*}
Script that solves your problem.
#!/bin/bash
monitor_sock_raw1="socket,id=hmqmondev,port=55919,host=127.0.0.1,nodelay,server,nowait"
msock=(${monitor_sock_raw1##*port=})
echo ${msock%%,*}
Related
I have multiple strings, where I want to extract everything between the last occurrence of a string (release-) and some characters (--). More specifically, for a sting like the following:
inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE
I want to have the following output:
PI_4.1-Sprint-3.1a
I created a regex online, which you can find here. There regex is the following:
.*release-(.*)--.*
However, when I am trying to use this script into a bash script, it wont work. Here is an example.
artifactoryVersion="inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE"
[[ "$artifactoryVersion" =~ (.*release-(.*)--.*) ]]
echo $BASH_REMATCH[0]
echo $BASH_REMATCH[1]
Will return:
inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE[0]
inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE[1]
Do you have any ideas about how can I accomplish my goal in bash?
You may use:
s='inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE'
rx='.*-release-(.*)--'
[[ $s =~ $rx ]] && echo "${BASH_REMATCH[1]}"
PI_4.1-Sprint-3.1a
Code Demo
Your regex appears correct but make sure to use "${BASH_REMATCH[1]}" to extract first capture group in the result.
You need to use the following:
#!/bin/bash
artifactoryVersion="inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE"
if [[ "$artifactoryVersion" =~ .*release-(.*)-- ]]; then
echo ${BASH_REMATCH[1]};
fi
See the online demo
Output:
PI_4.1-Sprint-3.1a
With your shown samples please try following BASH code with regex. I have also mentioned comments before executing each statement to understand each statement here.
##Shell variable named var being created here.
var="inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE"
##Mentioning regex which needs to be checked on later in program.
regex="(.*release-release)-(.*)--"
##Check condition on var variable with regex if match found then print 2nd capturing group value.
[[ $var =~ $regex ]] && echo "${BASH_REMATCH[2]}"
Explanation of regex: Following is the detailed explanation for used regex.
regex="(.*release-release)-(.*)--": Creating shell variable named regex in which putting regular expression (.*release-release)-(.*)--.
Where regex is creating 2 capturing groups.
First matching everything till release-release(with greedy match), which is followed by a -(not captured anywhere).
Which is followed by a greedy match, which will basically match everything before -- to get the exactly needed value.
You can also do it with shell parameter expansions (it's slower than a bash regex but it's standard):
artifactoryVersion='inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE'
result=${artifactoryVersion##*-release-}
result=${result%%--*}
printf %s\\n "$result"
PI_4.1-Sprint-3.1a
Or directly with a bash parameter expansion and extended globing:
#!/bin/bash
shopt -s extglob
artifactoryVersion='inte_integration-abc-abcde-abcdefg-release-release-PI_4.1-Sprint-3.1a--1.0.2-RELEASE'
echo "${artifactoryVersion//#(*-release-|--*)}"
PI_4.1-Sprint-3.1a
I want to crop a string around a wildcard (or a pattern using a wildcard) in Bash, preferably using parameter expressions or grep, anything but sed if it's possible. And then get that wildcard in a variable.
Example of string:
DESERT=pie-cake_berry_cream-sirup
And I have a pattern with a wildcard:
_*_
The pattern will match with "_berry_" on my string. I want to run a bash command over my string, and return "berry" if I use this particular pattern.
Just use BASH_REMATCH to access the captured group:
if [[ $DESERT =~ _(.*)_ ]]; then
echo ${BASH_REMATCH[1]}
fi
This says: hey, take the variable $DESERT and capture whatever is placed in between _ and _. If there is such match, the result is captured in the special variable $BASH_REMATCH.
So in your example:
$ DESERT=pie-cake_berry_cream-sirup
$ if [[ $DESERT =~ _(.*)_ ]]; then echo ${BASH_REMATCH[1]}; fi
Returns
berry
From man bash - Bash variables:
BASH_REMATCH
An array variable whose members are assigned by the ‘=~’ binary
operator to the [[ conditional command (see Conditional Constructs).
The element with index 0 is the portion of the string matching the
entire regular expression. The element with index n is the portion of
the string matching the nth parenthesized subexpression. This variable
is read-only.
I have a file like this little example:
# ...
# mode=dev
# ...
Somewhere in this file there is a "variable" within a comment. And i would like to get the value with regex in a Shell script.
My code so far:
#!/bin/bash
conf=$(<"/etc/test.conf") # Get the file content
regex='mode=(.*)$' # Set a regex
if [[ $conf =~ $regex ]]; then # Search for the regex in the file
# We found it, so ...
echo "${BASH_REMATCH[1]}" # ... here is the value
fi
My big problem is, that it will not find the value :(
I tried a lot of different regex expressions and tested them with https://regex101.com/ , but it seems, that the Shell regex interprator is different from pcre and python.
My best solution was to find the mode= and everything after it. So is there a way to get only the value? The start is easy ... find mode=. But how do I say the shell regex to get everything behind mode= until the next linebreak? and not beyond this linebreak?
Something with \n (unix linebreak) and $ (end of string) did not work for me :(
Thanks for the help,
greetings
You can use this regex to get your match:
conf=$(<"/etc/test.conf")
regex=$'mode=([^\n]*)'
[[ $conf =~ $regex ]] && echo "${BASH_REMATCH[1]}"
Output:
dev
Regex $'mode=([^\n]*)' will match literal text mode= followed by 0 or more of any character that is not \n.
i'd like to know if its possible to get named regular expression with grep -P(linux bash) from a non formatted string? well.. from any string
For example:
John Smith www.website.com john#website.com jan-01-2001
to capture as
$name
$website
$email
$date
but it seems I cant pass any variables from output?
echo "www.website.com" | grep -Po '^(www\.)?(?<domain>.+)$' | echo $domain
has no output
no. grep is a process. you are talking about environment propagation from child to parent. that's forbidden.
instead, you can do
DATA=($your_line)
then take name=DATA[0] so and forth.
or another way using awk:
eval "`echo $your_line | awk '
function escape(s)
{
gsub(/'\''/,"'\''\"'\''\"'\''", s);
s = "'\''"s"'\''";
return s;
}
{
print "name="escape($1);
print "family_name="escape($2);
print "website="escape($3);
print "email="escape($4);
print "date="escape($5);
}'`"
the sense here is to propagate the info via stdout and eval it in the parent environment.
notice that, here, escape function will escape any string correctly such that nothing will be interpreted wrongly(like the evil of quotes).
following is the output from my jessie:
name='John'
family_name='Smith'
website='www.website.com'
email='john#website.com'
date='jan-01-2001'
if the family name is O'Reilly, the eval result will still be correct:
name='John'
family_name='O'"'"'Reilly'
website='www.website.com'
email='john#website.com'
date='jan-01-2001'
Grep is an independent command-line utility; it does not run inside of bash. So it couldn't create bash variables even if it wanted to.
However, bash has a regular expression matcher built-in. It's not a perl-compatible regex matcher, so it doesn't implement named captures. (To be precise, it matches Posix extended regular expressions, the same as grep -E.) But it does implement numbered captures.
You do regular expression matches with the =~ operator inside of the [[ ... ]] compound command syntax. If the regular expression matches, then the expression succeeds, and the captures are inserted into the array variable BASH_REMATCH. ${BASH_REMATCH[0]} will be the entire matched substring, and the remaining elements, starting with ${BASH_REMATCH[1]}, will be the individual captures in order.
For example:
$ url=www.example.com
$ [[ $url =~ ^(www\.)?(.*) ]]
$ echo "${BASH_REMATCH[1]}"
www.
$ echo "${BASH_REMATCH[2]}"
example.com
I want to parse strings similar to the following into separate variables using regular expressions from within Bash:
Category: entity;scheme="http://schemas.ogf.org/occi/core#";class="kind";title="Entity";attributes="occi.core.id occi.core.title";
or
Category: resource;scheme="http://schemas.ogf.org/occi/core#";class="kind";title="Resource";rel="http://schemas.ogf.org/occi/core#entity";attributes="occi.core.summary";
The first part before "title" is common to all strings, the parts title and attributes are optional.
I managed to extract the mandatory parameters common to all strings, but I have trouble with optional parameters not necessarily present for all strings. As far as I found out, Bash doesn't support Non-capturing parentheses which I would use for this purpose.
Here is what I achieved thus far:
CATEGORY_REGEX='Category:\s*([^;]*);scheme="([^"]*)";class="([^"]*)";'
category_string='Category: entity;scheme="http://schemas.ogf.org/occi/core#";class="kind";title="Entity";attributes="occi.core.id occi.core.title";'
[[ $category_string =~ $CATEGORY_REGEX ]]
echo ${BASH_REMATCH[0]}
echo ${BASH_REMATCH[1]}
echo ${BASH_REMATCH[2]}
echo ${BASH_REMATCH[3]}
The regular expression I would like to use (and which is working for me in Ruby) would be:
CATEGORY_REGEX='Category:\s*([^;]*);\s*scheme="([^"]*)";\s*class="([^"]*)";\s*(?:title="([^"]*)";)?\s*(?:rel="([^"]*)";)?\s*(?:location="([^"]*)";)?\s*(?:attributes="([^"]*)";)?\s*(?:actions="([^"]*)";)?'
Is there any other solution to parse the string with command line tools without having to fall back on perl, python or ruby?
I don't think non-capturing groups exist in bash regex, so your options are to use a scripting language or to remove the ?: from all of the (?:...) groups and just be careful about which groups you reference, for example:
CATEGORY_REGEX='Category:\s*([^;]*);\s*scheme="([^"]*)";\s*class="([^"]*)";\s*(title="([^"]*)";)?\s*(rel="([^"]*)";)?\s*(location="([^"]*)";)?\s*(attributes="([^"]*)";)?\s*(actions="([^"]*)";)?'
category_string='Category: entity;scheme="http://schemas.ogf.org/occi/core#";class="kind";title="Entity";attributes="occi.core.id occi.core.title";'
[[ $category_string =~ $CATEGORY_REGEX ]]
echo "full: ${BASH_REMATCH[0]}"
echo "category: ${BASH_REMATCH[1]}"
echo "scheme: ${BASH_REMATCH[2]}"
echo "class: ${BASH_REMATCH[3]}"
echo "title: ${BASH_REMATCH[5]}"
echo "rel: ${BASH_REMATCH[7]}"
echo "location: ${BASH_REMATCH[9]}"
echo "attributes: ${BASH_REMATCH[11]}"
echo "actions: ${BASH_REMATCH[13]}"
Note that starting with the optional parameters we need to skip a group each time, because the even numbered groups from 4 on contain the parameter name as well as the value (if the parameter is present).
You can emulate non-matching groups in bash using a little bit of regexp magic:
_2__ _4__ _5__
[[ "fu#k" =~ ((.+)#|)((.+)/|)(.+) ]];
echo "${BASH_REMATCH[2]:--} ${BASH_REMATCH[4]:--} ${BASH_REMATCH[5]:--}"
# Output: fu - k
Characters # and / are parts of string we parse.
Regexp pipe | is used for either left or right (empty) part matching.
For curious, ${VAR:-<default value>} is variable expansion with default value in case $VAR is empty.