能够在 bash SED 中使用变量

Question

I'm trying to use sed to add a variable prefix to my command...

datestamp="$(date +'%D %r %Z')"
prefix=$("$datestamp site=$i space=$number")

prefix=$("site=$i space=$number")
echo test this thing | sed 's/^/$prefix /'

I'm expecting site=abc space=12 test this thing

Answer 1

Simply replace the single quotes for the sed line with double quotes, and that should do the trick.

datestamp="$(date +'%D %r %Z')"
prefix="$datestamp site=$i space=$number"
echo test this thing | sed "s@^@$prefix @"