how to stop parsing shell variables in bash script inside cat area?

jackandking · 03-10-2009, 12:56 AM

e.g.:

Code:

#!/bin/bash
cat << EOF >>/tmp/test
test `hostname` = "vm20" || return
EOF

expected content of /tmp/test:
test `hostname` = "vm20" || return

actually get:
test vm20 = "vm20" || return

further more, if there are variables like "$#,$a" inside the cat area they all will be parsed and replaced by their value in current shell.

how to stop this kind of parsing inside the cat area?

arungoodboy · 03-10-2009, 02:34 AM

You can escape the backticks using '\' to stop bash from expanding it. e.g.

Code:

 test \`hostname\` = "vm20" || return

The same holds for other things like $variable: use \$variable instead.

jackandking · 03-10-2009, 06:44 AM

got it, thanks.