The `$@` program

$@ prints the positional parameters of an execline script.

Interface

     $@ [ -n ] [ -0 | -d delimchar ]

$@ reads the number n of "positional parameters" in the # environment variable. If that variable is not set or does not contain a valid n, $@ exits 100.
$@ prints the value of the 1 environment variable, then delimchar, then the value of the 2 environment variable... and so on until n. If one of these variables is not set, $@ exits 100.
If everything runs OK, $@ exits 0. This makes it one of the rare "exiting" execline commands.

-n : chomp. Do not print the last delimchar.
-d delimchar : use the character delimchar as separator between the arguments. Default: \n. If delimchar has more than one character, only the first one is used. If delimchar is the empty string, then $@ will output the positional parameters as a sequence of netstrings (and the -n option will be ignored).
-0 : use the null character as separator. Any -d argument will be ignored. Warning: this option should only be used to feed data to programs that know how to handle null-separated lists.

The $@ word gets interpreted by execline as the list of all positional parameters. To make sure it's not substituted, and correctly refers to the $@ command, make sure to escape the $ character in execline scripts: \\$@.
You can use $@ -d "" along with the forbacktickx command to reliably loop over the positional parameters:
```
 #!/command/execlineb
 forbacktickx -d "" ARG { \\$@ -d "" }
 dosomething $ARG
```
will call dosomething in turn on each argument to the script. That will work even if those arguments contain spaces, newlines, or other fancy characters.
Alternatively, instead of encoding data into a netstring, you can use a null-separated list, which will work the same way:
```
 #!/command/execlineb
 forbacktickx -0 ARG { \\$@ -0 }
 dosomething $ARG
```