[PHP] About environment variables

cereal 0 288 Views

Simple Advice

This is just a reminder. When setting environment variables through .htaccess, CLI or dotenv use filter_var() to evaluate a boolean. For example, start the built-in PHP server with these variables:

DEBUG=FALSE LOG=TRUE SMS=1 SMTP=0 CONNECT=yes BACKUP=no php -d variables_order=EGPCS -S localhost:8000

And then test through boolval(): if you forget to use 1 and 0, then something can go wrong as the variable is evaluated like a string and will always return TRUE. By using filter_var(), with the appropriate filter to validate boolean, you get more flexibility as it:

returns TRUE for "1", "true", "on" and "yes". Returns FALSE otherwise.

Docs:http://php.net/manual/en/filter.filters.validate.php

# environment variable from inside the script $_ENV['TEST'] = FALSE; # boolval() var_dump(boolval($_ENV['DEBUG'])); # bool(true) var_dump(boolval($_ENV['LOG'])); # bool(true) var_dump(boolval($_ENV['SMS'])); # bool(true) var_dump(boolval($_ENV['SMTP'])); # bool(false) var_dump(boolval($_ENV['CONNECT'])); # bool(true) var_dump(boolval($_ENV['BACKUP'])); # bool(true) var_dump(boolval($_ENV['TEST'])); # bool(false) # filter_var() var_dump(filter_var($_ENV['DEBUG'] , FILTER_VALIDATE_BOOLEAN)); # bool(false) <-- diff var_dump(filter_var($_ENV['FOO'] , FILTER_VALIDATE_BOOLEAN)); # bool(true) var_dump(filter_var($_ENV['SMS'] , FILTER_VALIDATE_BOOLEAN)); # bool(true) var_dump(filter_var($_ENV['SMTP'] , FILTER_VALIDATE_BOOLEAN)); # bool(false) var_dump(filter_var($_ENV['CONNECT'], FILTER_VALIDATE_BOOLEAN)); # bool(true) var_dump(filter_var($_ENV['BACKUP'] , FILTER_VALIDATE_BOOLEAN)); # bool(false) <-- diff var_dump(filter_var($_ENV['TEST'] , FILTER_VALIDATE_BOOLEAN)); # bool(false)
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