//**
// Using ExecuteScriptText, gets the environment variables.
// Variables are returned as a carriage-return-separated
// string.
//
// Usage examples:
// 	print GetEnvironmentVariables()		// Prints all variables to Igor's command history
// 	String sys_path = StringByKey("PATH", GetEnvironmentVariables(), "=", "\r")
//*
Function/S GetEnvironmentVariables()
 
	String envInfoString = ""
 
 
	// This has to be done differently depending on the operating system.
	String platform = IgorInfo(2)
	String errorMessage
	StrSwitch (platform)
		Case "Windows":
			try
				// Do some setup.
				String tmpDir = SpecialDirPath("Temporary", 0, 0, 0)
				AbortOnValue (numtype(strlen(tmpDir)) != 0 || !(strlen(tmpDir) > 0)), 1
 
 
				// Make sure that the directory we just got is, in fact, a directory.
				GetFileFolderInfo/Q tmpDir
				AbortOnValue (V_Flag >= 0 && !V_isFolder), 3
 
				// Set an Igor symbolic path to the temporary directory.
				String tmpDirectoryPath = UniqueName("tmpPath", 12, 0)
				NewPath/Q $(tmpDirectoryPath), tmpDir
				AbortOnValue (V_flag), 5		// Setting of the new path failed.
 
				// Write a temporary batch file to the temporary directory that will
				// call the "set" command from the command shell and save the
				// output of the command to a temporary file.
				String tempBatFileName, tempResultsFileName
				String tempBatFileFullPath, tempResultsFileFullPath
				Variable tempBatFileRefNum, tempResultsFileRefNum
 
				sprintf tempBatFileName, "IgorGetEnvironmentVars_%.4u.bat", abs(trunc(StopMsTimer(-2)))
				Open/P=$(tmpDirectoryPath)/T=".bat"/Z=1 tempBatFileRefNum as tempBatFileName
				AbortOnValue (V_flag != 0), 7
 
				// Add a path separator character to the end of the path, if necessary, and add on the file name.
				tempBatFileFullPath = ParseFilePath(2, tmpDir, ":", 0, 0) + tempBatFileName
 
				// Convert the path into a windows path that uses "\" as the path separator.
				tempBatFileFullPath = ParseFilePath(5, tempBatFileFullPath, "\\", 0, 0)
 
				sprintf tempResultsFileName, "IgorGetEnvironmentVars_%.4u.txt", abs(trunc(StopMsTimer(-2)))			
 
				// Add a path separator character to the end of the path, if necessary, and add on the file name.
				tempResultsFileFullPath = ParseFilePath(2, tmpDir, ":", 0, 0) + tempResultsFileName
 
				// Convert the path into a windows path that uses "\" as the path separator.
				tempResultsFileFullPath = ParseFilePath(5, tempResultsFileFullPath, "\\", 0, 0)
 
				fprintf tempBatFileRefNum, "set > \"%s\"\r\n", tempResultsFileFullPath
				Close tempBatFileRefNum
 
				// Call the batch file we just created.  Timeout after 2 seconds if this doesn't succeed.
				String scriptText
				sprintf scriptText, "cmd.exe /C \"%s\"", tempBatFileFullPath
				ExecuteScriptText/W=2/Z scriptText
 
				// Check for an error.
				AbortOnValue (V_flag != 0), 9
 
				// Check that the temporary results file exists.
				GetFileFolderInfo/Z=1/Q/P=$(tmpDirectoryPath) tempResultsFileName
				AbortOnValue (V_flag != 0 || !(V_isFile)), 10
 
				// Get the results from the temporary file created by the batch file.
				Open/P=$(tmpDirectoryPath)/R/Z=1 tempResultsFileRefNum as tempResultsFileName
				AbortOnValue (V_flag != 0), 12
 
				String buffer
				do
					FReadLine tempResultsFileRefNum, buffer
					if (strlen(buffer) <= 0)
						break
					else
						envInfoString += buffer
					endif
				while (1)	
				Close tempResultsFileRefNum
 
				// Delete the temporary batch file and temporary results file.
				DeleteFile/P=$(tmpDirectoryPath)/Z=1 tempBatFileName
				DeleteFile/P=$(tmpDirectoryPath)/Z=1 tempResultsFileName
				// If we get an error here we don't really care.  We've already got
				// the goods, so just run.
				break
			catch
				// Error handling
				Switch (V_abortCode)
					Case 1:
						errorMessage = "Could not locate the operating system's temporary directory, so can't get environment variables."
						break
					Case 3:
						errorMessage = "Could not locate the operating system's temporary directory, so can't get environment variables."
						break
					Case 5:
						errorMessage = "Igor was unable to create a symbolic path to the temporary file directory."
						break
					Case 7:
						errorMessage = "Igor was unable to create a batch file in the temporary directory."
						break
					Case 9:
						errorMessage = "Igor was unable to execute the batch file to read the environment variables."
						break
					Case 10:
						errorMessage = "Igor was unable to locate or read the temporary file containing environment variables."
						break
					Case 12:
						errorMessage = "Igor was unable to open the temporary file containing environment variables."
						break
					default:
						errorMessage = "An unspecified error occurred while trying to read the environment variables."						
				EndSwitch
				print errorMessage
				KillPath/Z $(tmpDirectoryPath)
				return ""
 
			endtry
 
		Case "Macintosh":
			// This is a lot easier on the Macintosh because we can just use AppleScript.
			try
				String appleScriptCommand = "do shell script \"env\""
				ExecuteScriptText/Z appleScriptCommand
				AbortOnValue V_flag, 1
 
				envInfoString = S_Value
			catch
				errorMessage = "Could not execute AppleScript command."
				print errorMessage
				return ""				
			endtry
			break
	EndSwitch
	return envInfoString
End