Pipelines and Execution Series

| is used to direct the standard output of a command to the standard input of another.

&& is used to conditionally execute a command based on the success of the prior command.

|| is used to conditionally execute a command based on the failure of the prior command.

Note: Unlike what you may be used to, a return status of 0 (zero)

denotes success. Anything else signifies failure.

e.g.

[ -f nonexistentfile ] && cat nonexistentfile

[ -f nonexistentfile ] || echo 'No such file!'

--> No such file!

echo "hello there 1" | wc -c

--> 14

[ `echo 'hello there 1' | wc -c` -gt 13 ] && echo 'Success'

--> Success