bash heredoc
reference article
- heredoc multi line comment
<< tips
hello world
tips
echo hello lina
- heredoc cat message
cat << tips
hello world
see you again
love story
tips
- heredoc redirection message
cat << tips > doc
hello world
see you again
love story
tips
cat doc
- heredoc with variable
music1="see you again"
music2="love story"
cat << tips
hello world
${music1}
${music2}
tips
- heredoc but variable but not replace
music1="see you again"
music2="love story"
cat << 'tips'
hello world
${music1}
${music2}
tips
- heredoc suppress tab space with - symbol
cat <<- tips
hello world
see you again
love story
tips
