Sed replace a part of a path with the current directory

I have a file containing a lot paths. I need to replace all those path (containing build numbers) by the current path.
In other word in my file I have like :

/build/8b7yrg_k/12/src/main/myfile

and I want (if I’m in /build/home/0/):

/build/home/0/src/main/myfile

What I’m trying is to do :

sed 's,/build/'.+'/'[0-9]+'/','$PWD',g

But the the command doesn’t find the pattern. I also tried to add \ or to remove the ‘ but I don’t manage to match the desired patterns

>Solution :

There are several issues:

• In POSIX BRE patterns, + is treated as a literal char, not a quanitifier
• In single quotes, variable expansion is not enabled
• The replacement is missing a slash (even if you fix the above, the current directory will appear glued to the remaining part of your path).

You can use

sed -E 's,/build/[^/]+/[0-9]+/,'"$PWD"/',g'
sed 's,/build/[^/]*/[0-9]*/,'"$PWD"/',g'

Details:

• /build/[^/]+/[0-9]+/ is a POSIX ERE regex (enabled with -E) that matches /build/, one or more chars other than /, then a /, one or more digits and then a / chr
• /build/[^/]*/[0-9]*/ is a POSIX BRE pattern that does the same as above
• "$PWD"/ – the current directory variable is inside double quotes, and the / is added to make this replacement pattern work.

See the online demo:

#!/bin/bash
s='/build/8b7yrg_k/12/src/main/myfile'
sed -E 's,/build/[^/]+/[0-9]+/,'"$PWD"/',g' <<< "$s"
sed 's,/build/[^/]*/[0-9]*/,'"$PWD"/',g' <<< "$s"

Output:

/home/3octv4/src/main/myfile
/home/3octv4/src/main/myfile