Difference between $? and $LastExitCode in PowerShell

75
votes

In PowerShell, what is the difference between $? and $LastExitCode?

I read about automatic variables, and it said:

$? Contains the execution status of the last operation. It contains TRUE if the last operation succeeded and FALSE if it failed.

$LastExitCode Contains the exit code of the last Windows-based program that was run.

In the definition of $? it doesn't explain what succeed and fail mean.

I ask because I presumed that $? is True if and only if $LastExitCode is 0, but I found a surprising counter-example: $LastExitCode=0 but $?=False in PowerShell. Redirecting stderr to stdout gives NativeCommandError.

1
windowspowershellcommand-line

1 Answers

89
votes

$LastExitCode is the return code of native applications. $? just returns True or False depending on whether the last command (cmdlet or native) exited without error or not.

For cmdlets failure usually means an exception, for native applications it's a non-zero exit code:

PS> cmd /c "exit 5"
PS> $?
False
PS> cmd /c "exit 0"
PS> $?
True

Cancelling a cmdlet with Ctrl+C will also count as failure; for native applications it depends on what exit code they set.