Como você incorpora strings dentro dos comentários dentro de um heredoc?

Question

Isso não funciona, o comentário não contém a string IP_ADDR

SSH_UN='user'
IP_ADDR='192.168.1.101'

cat <<"EOF" >> .ssh/config
# VirtualBox (VB) on user's laptop at $IP_ADDR
Host laptopvb
  Hostname $IP_ADDR
  User $SSH_UN
  ForwardAgent yes
EOF

    

Answer 1

Remova as aspas duplas em torno do EOF :

IP_ADDR='192.168.1.101'
cat <<EOF >> .ssh/config
# VirtualBox (VB) on hobs laptop at $IP_ADDR
Host laptopvb # manually set as a static IP on the VB
  Hostname $IP_ADDR
  User $SSH_UN
  ForwardAgent yes
EOF

De acordo com o manual do bash :

The format of here-documents is:

       <<[-]word
               here-document
       delimiter

No parameter expansion, command substitution, arithmetic expansion, 
or pathname expansion is performed on word. If any characters in word are quoted, 
the delimiter is the result of quote removal on word, and the lines in the
here-document are not expanded. If word is unquoted, all lines of the
here-document are subjected to parameter expansion, command substitution,
and arithmetic expansion.