Lesson 47 of 55
8 mins readPython CLI Arguments (@ARGV) & Environment (%ENV)
In Plain English
Perl stores command-line arguments in `@ARGV` (0-indexed without script name) and system environment variables in the `%ENV` special hash.
Deep Dive: How It Works
@ARGV Array: Holds all CLI arguments passed to the script ($ARGV[0] is the first option).
%ENV Hash: Key-value map of environment variables (e.g., `$ENV{USER}`, `$ENV{PATH}`).
$0 Special Variable: Holds the name/path of the currently running Perl script.
Core Rules to Remember
@ARGV for CLI Arguments: List of parameters passed on invocation.
%ENV for System Environment: Read and write environment variables via `$ENV{VAR_NAME}`.
Live Interactive Example
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Python 3.12
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Output Console
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How it works: Inspected arguments and read the %ENV hash.
Your Turn: Micro Challenge
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Micro Exercise
Read Environment Setting
- Set `$ENV{SERVICE_TIER} = "Enterprise";`
- Print `"Active Tier: $ENV{SERVICE_TIER}\n"`.
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Sandbox Output
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