Re: output redirection with process substitution asynchronous?

[pk]

pjodrr wrote:

> Hello,
> 
> how can I prefix every line of output of some command with a
> timestamp?  I thought like this:
> 
> $ exec 3> >(while read line; do echo "$(date): $line"; done)
> $ seq 4 >&3
> Friday, December  4, 2009  4:20:29 PM MET: 1
> $ Friday, December  4, 2009  4:20:29 PM MET: 2
> Friday, December  4, 2009  4:20:29 PM MET: 3
> Friday, December  4, 2009  4:20:29 PM MET: 4
> 
> please note that the prompt ($) returns before the command completes.
> Why is the
> process substitution asynchronous?
> Does anybody know of a better way to accomplish this?

What's wrong with

seq 4 | while read line; do echo "$(date): $line"; done