Is there a Unix utility to prepend timestamps to stdin?
Could try using awk:
<command> | awk '{ print strftime("%Y-%m-%d %H:%M:%S"), $0; fflush(); }'You may need to make sure that <command> produces line buffered output, i.e. it flushes its output stream after each line; the timestamp awk adds will be the time that the end of the line appeared on its input pipe.
If awk shows errors, then try gawk instead.