Article of the week: A Brief History of Containers
For this trip, step into my DeLorean time machine, and let’s journey to 1979, when the concept of containers first emerged.
Tip of the week: An introduction to HEREDOCs:
# basic output to stdout
cat << EOF
The current directory is $PWD.
EOF
# basic output to a file
cat << EOF > /path/to/file
The variable $foo will be interpreted.
EOF
# don't interpret variables
cat << 'EOF' > /path/to/file
The variable $bar will not be interpreted.
EOF
# pipe the heredoc through a command
cat << 'EOF' | sed 's/foo/bar/g' > /path/to/file
All instances of "foo" will be replaced.
EOF
# write the heredoc to a file using sudo
cat << 'EOF' | sudo tee /path/to/file
This file will be owned by 'root'.
EOF
# use a heredoc, but indented (the HEREDOC must use a tab character, not spaces!)
if true; then
cat <<- EOF
1. One
2. Two
3. Three
EOF
fi