.bash_profile sed: \1 not defined in the RE
bash, homebrew, sed
Solution
You should use `\(.*\)` instead of `(.*)`.
`sed` uses Basic Regular Expressions (BRE) by default, which uses `\(` and `\)` for group capturing, not just `(` and `)` as used in Extended Regular Expressions (ERE). Since your expression used `(.*)` instead of `\(.*\)`, it is not recognised as a group capture, and thus nothing is captured for use with `\1`.
Some `sed` implementations, such as the ones provided by GNU and BSD, do have an extension for specifying the use of ERE, but it is not specified by POSIX, and you cannot use it if you want to be portable.
Problem
I've to set up a local web development environment on my OS X 10.9 and installed Homebrew. Next step in my guide tells me to add logic to my `~/.bash_profile` with the following command: ``` echo "export PATH=\$(echo \$PATH | sed 's|/usr/local/bin||; s|/usr/local/sbin||; s|::|:|; s|^:||; s|(.*)|/usr/local/bin:/usr/local/sbin:\1|')" >> ~/.bash_profile && source ~/.bash_profile ``` When I enter it in the terminal I get: ``` sed: 1: "s|/usr/local/bin||; s|/ ...": \1 not defined in the RE ``` Is it `export PATH=/usr/local/bin:/usr/local/sbin:$PATH` that should be written to my `.bash_profile`? And why do I get that error?