LinuxQuestions.org - [SOLVED] * and @ in substring extraction in bash

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- - * and @ in substring extraction in bash (https://www.linuxquestions.org/questions/linux-newbie-8/%2A-and-%40-in-substring-extraction-in-bash-4175611116/)

* and @ in substring extraction in bash

I understand how a substring extraction is done,

Code:

${string:position:length}

but I don't understand how I can actually use * or @ in this context. The explanation from Advanced Bash Scripting isn't enough:

If the $string parameter is "*" or "@", then this extracts a maximum of $length positional parameters, starting at $position.

Code:

echo ${*:2} # Echoes second and following positional parameters.

echo ${@:2} # Same as above.

echo ${*:2:3} # Echoes three positional parameters, starting at second.

So it extracts the maximum of $length position parameteres, but what from, if the string is * or @?

Can you offer any concrete examples?

from the command-line arguments when it was invoked

Code:

test@ws1:~$ cat /tmp/example.sh 

#!/bin/bash



echo "${@:1:2}"



test@ws1:~$ /tmp/example.sh one two three

one two

Right, I simply ignored the word group "positional parameter". That was clearly unambiguous. Thanks!

Not sure I understand the question. By positional parameters the tldp is referencing command line arguments.

Code:

#!/bin/bash

echo $*

echo ${*:2:3}



./myscript.sh 1 2 3 4 5

1 2 3 4 5

2 3 4

A bit late...