sqlplus username/password@connect_identifier_specified_in_argument @file_name

$scripts = dir *.sql
foreach($script in $scripts) {
    write-host sqlplus username/password"@"$args "@"$script.Name
}

PS C:codescripts> C:utilsrun_sql_scripts_on.ps1 identifier
sqlplus username/password@identifier @ ALERTS.sql

write-host sqlplus username/password`@$args `@$script.Name

5>echoargs username/password"@"$args "@"$script.Name
Arg 0 is <username/password@>
Arg 1 is <@>
Arg 2 is <test.txt>

6>echoargs "username/password`@$args" "`@$($script.Name)"
Arg 0 is <username/password@>
Arg 1 is <@test.txt>