Print and concatenate files. More information: https://keith.github.io/xcode-man-pages/cat.1.html.
stdout
:cat {{path/to/file}}
cat {{path/to/file1 path/to/file2 ...}} > {{path/to/output_file}}
cat {{path/to/file1 path/to/file2 ...}} >> {{path/to/output_file}}
cat -u {{/dev/tty12}} > {{/dev/tty13}}
stdin
to a file:cat - > {{path/to/file}}
cat -n {{path/to/file}}
M-
prefix if non-ASCII):cat -v -t -e {{path/to/file}}