macshome · May 2, 2024 12:48 · macshome · May 2, 2024
diff --git a/EnvironmentVariables.swift b/EnvironmentVariables.swift
 import Foundation

 // A playground to see different ways to get environment variables in Swift

 // Foundation is the easiest way using the awesome ProcessInfo class.

 // Get all of the environment variables for your running process in a Dictionary.
 let foundationEnv = ProcessInfo().environment

 print("********** ProcessInfo Environment **********")
 foundationEnv.forEach { print($0) }

 // You can use subscript to just get the one you want.
 if let foundationUser = foundationEnv["USER"] {
    print("\n********** ProcessInfo Singe Value **********")
    print(foundationUser)
 }

 // You can also drop down to Darwin and use the standard POSIX tools.
 // Note that these are just for the POSIX environment and won't have
 // all of the Foundation runtime specific values.

 // Get all of the environment variables for your process like you are on a VAX.
 let posixEnv = environ

 // There are a lot of ways to slice and dice an array of CCHar values.
 // This way is a lazy one to convert it to [UnsafeMutablePointer<CChar>?].
 let bufray = Array(UnsafeBufferPointer(start: posixEnv, count: MemoryLayout.stride(ofValue: posixEnv)))

 print("\n********** POSIX Environment **********")

 // Old fashioned fast enumeration still works fine in Swift.
 // I added an internal if-let so that there is no forced unwrapping.
 for item in bufray {
    if let item {
        print(String(cString: item))
    }
 }

 // Get just the variable you want like it's 1979.
 let posixUser = String(cString: getenv("USER"))
 print("\n********** POSIX Single Value **********")
 print(posixUser)
	import Foundation

	// A playground to see different ways to get environment variables in Swift

	// Foundation is the easiest way using the awesome ProcessInfo class.

	// Get all of the environment variables for your running process in a Dictionary.
	let foundationEnv = ProcessInfo().environment

	print("******** ProcessInfo Environment ********")
	foundationEnv.forEach { print($0) }

	// You can use subscript to just get the one you want.
	if let foundationUser = foundationEnv["USER"] {
	print("\n******** ProcessInfo Singe Value ********")
	print(foundationUser)
	}

	// You can also drop down to Darwin and use the standard POSIX tools.
	// Note that these are just for the POSIX environment and won't have
	// all of the Foundation runtime specific values.

	// Get all of the environment variables for your process like you are on a VAX.
	let posixEnv = environ

	// There are a lot of ways to slice and dice an array of CCHar values.
	// This way is a lazy one to convert it to [UnsafeMutablePointer<CChar>?].
	let bufray = Array(UnsafeBufferPointer(start: posixEnv, count: MemoryLayout.stride(ofValue: posixEnv)))

	print("\n******** POSIX Environment ********")

	// Old fashioned fast enumeration still works fine in Swift.
	// I added an internal if-let so that there is no forced unwrapping.
	for item in bufray {
	if let item {
	print(String(cString: item))
	}
	}

	// Get just the variable you want like it's 1979.
	let posixUser = String(cString: getenv("USER"))
	print("\n******** POSIX Single Value ********")
	print(posixUser)