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Difference between. / executable and. executable

In a shell, what's the difference between?

. executable

and

./executable

In the first, the hot spot is for source

right? So is there a difference between ./executable

and source executable

?

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3 answers


is there any difference between. / executable and the original executable?

The main difference,

./foo.sh      - foo.sh will be executed in a sub-shell
source foo.sh - foo.sh will be executed in current shell

Some example might help explain the difference:

let's say we have foo.sh

:

#!/bin/bash
VAR=100

enter it:

$ source foo.sh 
$ echo $VAR
100


If you:

./foo.sh
$ echo $VAR
[empty]

another example, bar.sh 

#!/bin/bash
echo "hello!"
exit 0

if you execute it like:

$ ./bar.sh
hello
$

but if you use it:

$ source bar.sh
<your terminal exits, because it was executed with current shell>
0


source


./executable

launches an executable file located in the current working directory. ( executable

not enough for this if $PATH

not .

, and usually it isn't). In this case, it executable

could be a binary elf or a script starting with #!/some/interpreter

, or whatever you can exec

(on Linux, that's potentially everything, thanks to the module binfmt

).



. executable

prints a shell script into your current shell, whether it has execute permissions or not. No new process is created. The bash

script is searched according to the variable $PATH

. The script can set environment variables that will stay set in your shell, define functions and aliases, etc.

+6


source


In the second, you specify the path: ./

- the current working directory, so it does not search in PATH

for the executable, but in the current directory.

source

takes an executable file as a parameter and executes it in the current process.

0


source






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