sed error: "invalid reference \1 on `s' command's RHS"
Don't you need to actually capture for that to work? i.e. for variant #2:
-r -e "s/WARNING: (\([a-zA-Z0-9./\\ :-]\+\))/${warn}WARNING: \1${c_end}/g" \
(Note: untested)
Without the -r
argument back-references (like \1
) won't work.
This error is common for parentheses that are not escaped. Escape them and try again.
For example:
/^$/b
:loop
$!{
N
/\n$/!b loop
}
s/\n(.)/\1/g
Should be escaped with backslashes before each parenthesis:
/^$/b
:loop
$!{
N
/\n$/!b loop
}
s/\n\(.\)/\1/g
If the -r
/--regexp-extended
option is not provided, then the capturing parentheses must be escaped.