Prepending a timestamp to each line of output from a command or executable

Question

I want to prepend a timestamp to each line of output from a command. For example:

foo
bar
baz

would become:

[2011-12-13 12:20:38] foo
[2011-12-13 12:21:32] bar
[2011-12-13 12:22:20] baz

where the time being prefixed is the time at which the line was printed. How can I achieve this with PowerShell?

Answer 1

Assuming your command is a external command named foo, you can pipe it's output through a ForEach-Object to add the timestamp:

foo | ForEach-Object { "$(Get-Date -Format "[yyyy-MM-dd HH:mm:ss]") $_" }