bash - Including "cat" command in unix shell Here Document -


i'm trying create here document shell script includes cat command. of course, fails when encountering 2nd cat. i'm performing lot of substitutions well, can't use "doc" escape trick.

myfile="/tmp/myipaddr" cat >/usr/bin/setipaddress <<_doc_  ...       out=`cat $myfile`  ... _doc_

i supposed echo file, seems kludgy , have lot of quotes , backticks i'd need escape?!? other thoughts?

suppose file contains

hello world

as written, script generate contain line

out=hello world

because command substitution performed immediately.

at least, need quote line in here document as

out="`cat $myfile`"

i suspect want include literal command substitution in resulting shell script. that, want quote backticks prevent them being evaluated immediately. better still, use recommended form of command substitution, $(...), , quote dollar sign.

cat >/usr/bin/setipaddress <<_doc_  ...       out=\$(cat $myfile)  ... _doc_

/usr/bin/setipaddress include line

out=$(cat /tmp/myipaddr)

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