I have an URL in the format like https://foo.bar.whoo.dum.io, for which I like to replace the foo string with something else. Of course, the foo part is unknown and can be anything.
I tried with a simple regex like (.+?)\.(.+), but it seems that regex in Bash is always greedy (or?).
My best attempt is to split the string by . and then join it back with the first part left out, but I was wondering, whether there is a more intuitive, different solution.
Thank you
There are a lot of ways of getting the desired output.
If you're sure the url will always start with https://, we can use parameter expansion to remove everything before the first . and then add the replacement you need:
input="https://foo.bar.whoo.dum.io"
echo "https://new.${input#*.}"
Will output
https://new.bar.whoo.dum.io
sed, cut, and awk based solutions.You can use sed:
url='https://foo.bar.whoo.dum.io'
url=$(sed 's,\(.*://\)[^/.]*,\1new_value,' <<< "$url")
Here, the sed command means:
\(.*://\) - Capturing group 1: any text and then ://[^/.]* - zero or more chars other than / and .\1new_value - replaces the match with the Group 1 and new_value is appended to this group value.See the online demo:
url='https://foo.bar.whoo.dum.io'
sed 's,\(.*://\)[^/.]*,\1new_value,' <<< "$url"
# => https://new_value.bar.whoo.dum.io
1st solution: Using Parameter expansion capability of bash here, adding this solution. Where newValue is variable with new value which you want to have in your url.
url='https://foo.bar.whoo.dum.io'
newValue="newValue"
echo "${url%//*}//$newValue.${url#*.}"
2nd solution: With your shown samples, please try following sed code here. Where variable url has your shown sample url value in it.
echo "$url" | sed 's/:\/\/[^.]*/:\/\/new_value/'
Explanation: Simple explanation would be, printing shell variable named url value by echo command and sending it as a standard input to sed command. Then in sed command using its capability of substitution here. Where substituting :// just before1st occurrence of . with ://new_value as per requirement.
