Parsing string with two captures in bash - regex

Question

I'm trying to parse a string with regex. A valid string is of the following format:
https://github.com/xyz/abc/a_123/project_14.git
The valid string should contain github.com and xyz or zyx. If the string is valid I want to capture abc/a_123 into $A and project_14 into $B.
What I did:
if [[ "$x" == *"github.com"* ]]; then
if [[ "$x" == *"xyz"* ]]; then
# (1)
elif [[ "$x" == *"zyx"* ]]; then
# (2)
else
return 1 # Invalid
fi
return 0 # Valid
fi
return 1 # Invalid
In both (1) and (2) I want to set $A and $B with the values (same behavior on different cases).
Also, I think that this solution is not good because it will enter the if-else in the case of https://github.com/bla/abc/a_123/xyz.git so I guess we need to change it to be "github.com/xyz". Also, how can I get rid of .git (if exists)?
Another example:
https://github.com/zyx/asdasdas/lalal/asdas/nu.git
# $A = asdasdas/lalal/asdas
# $B = nu
What is the proper way to achieve this goal?

Answer 1

Here is a way using regex:
url='https://github.com/xyz/abc/a_123/project_14.git'
if [[ $url =~ http[s]?:[/]{2}(github.com)[/]([[:alpha:]]+)(/.*)$ ]]
then
$A=${BASH_REMATCH[2]}
$B=${BASH_REMATCH[3]%.git}
fi
And here is a small proof of concept:
url='https://github.com/xyz/abc/a_123/project_14.git'
if [[ $url =~ http[s]?:[/]{2}(github.com)[/]([[:alpha:]]+)(/.*)$ ]]
then
echo ${BASH_REMATCH[2]} ${BASH_REMATCH[3]%.git}
fi
Resulting in:
xyz /abc/a_123/project_14

Answer 2

I think this does what you want :
#!/bin/bash
repo="https://github.com/xyz/abc/a_123/project_14.git"
[[ ! "$repo" =~ https:\/\/github.com\/[a-z]+\/[a-z]+\/[a-z]_[0-9]+\/.*.git ]] && exit
A=$( echo "$repo" | sed -E "s/(https:\/\/github.com\/[a-z]+)(\/[a-z]+\/[a-z]_[0-9]+\/)(.*.git)/\2/g" )
B=$( echo "$repo" | sed -E "s/(https:\/\/github.com\/[a-z]+)(\/[a-z]+\/[a-z]_[0-9]+\/)(.*.git)/\3/g" )
echo "$A"
echo "${B%%.git}"
Let me know if it helps

Answer 3

Would you please try the following:
strchk() {
local x=$1
if [[ $x =~ github.com/(xyz|zyx)/(.+)/(.+) ]]; then
A="${BASH_REMATCH[2]}"
B="${BASH_REMATCH[3]%.*}"
return 0
else
return 1
fi
}
Results:
strchk "https://github.com/xyz/abc/a_123/project_14.git" && echo "A=$A, B=$B"
=> A=abc/a_123, B=project_14
strchk "https://github.com/bla/abc/a_123/xyz.git" && echo "A=$A, B=$B"
=> <empty>
strchk "https://github.com/zyx/asdasdas/lalal/asdas/nu.git" && echo "A=$A, B=$B"
=> A=asdasdas/lalal/asdas, B=nu
Explanations:
The pattern github.com/(xyz|zyx)/ matches a string which contains
github.com/ followed by xyz/ or zyx/.
The next pattern (.+)/ matches a substring after xyz/ or zyx/ as long
as it reaches the rightmost slash then stores the captured substring within the parens into
a bash variable ${BASH_REMATCH[2]}.
The last pattern (.+) captures the remaining substring into
${BASH_REMATCH[3]}.
The parameter expansion ${BASH_REMATCH[3]%.*} removes the extension
after the dot if exists.
Hope this helps.