difference between #./ and #. ./

Question

whats the difference between executing script like

# ./test

and

# . ./test 

test is simple script for example

#!/bin/bash
export OWNER_NAME="ANGEL 12"
export ALIAS="angelique"

i know the results but im unsure what actually happens

Thanks

Answer 1

./foo executed foo if it's marked as executable and has a proper shebang line (or is an ELF binary). It will be executed in a new process.

. ./foo or . foo loads the script in the current shell. It is equal to source foo

With your example code you need to use the second way if you want the exported variables to be available in your shell.

Answer 2

With the dot alone, bash is "sourcing" the specified file. It is equivalent to the source builtin and attempts to include and execute the script within the same shell process.

The ./ starts a new process, and the current shell process waits for it to terminate.

Answer 3

The first implies that the script (or binary) be executable. With the script (possibly) containing a shebang line telling which interpreter to use.

The second is a short-hand for "execute [argument] as a shell script". The file passed as argument does not need the executable bit set.