zsh debug tracing with timestamp

zsh debug tracing with timestamp

[Paul Lew]

Any method to insert timestamp in front of the trace command turned on
by set -x?  We try to troubleshoot zsh startup time problem when
people sharing the common zsh startup across US and in India.
Timestamp will give us a clue which part take the longest and we
can then make proper adjustment.

Any help will be appreciated.

Re: zsh debug tracing with timestamp

[Bart Schaefer]

On Apr 14, 11:47pm, Paul Lew wrote:
} Subject: zsh debug tracing with timestamp
}
} Any method to insert timestamp in front of the trace command turned on
} by set -x?

Yes, if you're using 3.1.6 or later.  Just set PS4 using any of the usual
prompt expansion escapes, e.g.:

% PS4=': %D %T ; '
% set -x
% sleep 5; echo hello
: 01-04-15 12:43 ; sleep 5
: 01-04-15 12:43 ; echo hello
hello

If you need finer granularity, setopt promptsubst and use $SECONDS:

% setopt promptsubst
: 01-04-15 12:44 ; setopt promptsubst
% PS4=': %D %T {$SECONDS}; '
: 01-04-15 12:44 ; PS4=: %D %T {$SECONDS};  
% sleep 5; echo hello
: 01-04-15 12:45 {261}; sleep 5
: 01-04-15 12:45 {266}; echo hello
hello

One-second granularity is the smallest you can get.

I chose the :...; format so that you can cut-and-paste the trace output
into another shell and the leading timestamps will be ignored.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net   

Re: zsh debug tracing with timestamp

[Dan Nelson]

In the last episode (Apr 15), Bart Schaefer said:
> On Apr 14, 11:47pm, Paul Lew wrote:
> } Subject: zsh debug tracing with timestamp
> }
> } Any method to insert timestamp in front of the trace command turned on
> } by set -x?
> 
> Yes, if you're using 3.1.6 or later.  Just set PS4 using any of the usual
> prompt expansion escapes, e.g.:
> 
> % PS4=': %D %T ; '
> % set -x
> % sleep 5; echo hello
> : 01-04-15 12:43 ; sleep 5
> : 01-04-15 12:43 ; echo hello
> hello
> 
> If you need finer granularity, setopt promptsubst and use $SECONDS:

not needed; just use %D{%Y-%m-%d %H:%M:%S}, which will give you
seconds.

-- 
	Dan Nelson
	dnelson@emsphone.com