php8trace

About

php8trace is a command line php8 script tracer, using the PHP8 observer API It allow you to watch what a running php script is doing

Example

b.php

function takeanarrayandobjectandreturnarray($arg, $arg2) {
	return [1, $arg, $arg2];
}
function takearrayandreturnstring($arg) {
	takeanarrayandobjectandreturnarray($arg, (object)$arg);
	return 'foo';
}

function initial_call($arg1, $arg2) {
	return takearrayandreturnstring(['bar' => $arg2+2]);
}

initial_call('initial', 1);

php8trace b.php

starting php process with pid [ 425915 ]
> initial_call((string)"initial",(int)1,) [/home/ralauge/cohiba/maduro/b.php:11] 0x7F1CA7812080
  > takearrayandreturnstring((array)[bar => (int)3,]#1,) [/home/ralauge/cohiba/maduro/b.php:6] 0x7F1CA7812120
    > takeanarrayandobjectandreturnarray((array)[bar => (int)3,]#1,(stdClass)#1,) [/home/ralauge/cohiba/maduro/b.php:3] 0x7F1CA78121A0
    < takeanarrayandobjectandreturnarray((array)[bar => (int)3,]#1,(stdClass)#1,) [/home/ralauge/cohiba/maduro/b.php:3]: (array)[0 => (int)1,1 => (array)[bar => (int)3,]#1,2 => (stdClass)#1,]#3 0x7F1CA78121A0 (0.020981)
  < takearrayandreturnstring((array)[bar => (int)3,]#1,) [/home/ralauge/cohiba/maduro/b.php:7]: (string)"foo" 0x7F1CA7812120 (0.112057)
< initial_call((string)"initial",(int)1,) [/home/ralauge/cohiba/maduro/b.php:11]: (string)"foo" 0x7F1CA7812080 (0.202894)

To try

Install

make install
php8trace script.php

Added php ini settings

default ini when using the php8trace cmd wrapper	description
-d observer.instrument=1	enable module
-d observer.instrument_dump_timing=1	dump the time taken by function/call
-d observer.instrument_dump_execute_data_ptr=1	dump a ptr to the current struct execute_data. This ptr doesn't change between the start, and the return of a function; so it allow us to quickly jump betwen the two on a log file

Interesting keyboard shortcut of php8trace

standard

• Control + s: Default XOFF behavior
• Control + q: Default XON behavor
• Control + c: Forward SIGINT to the underlying php process
• Control + z: Forward SIGTSTP to the underlying php process

added one

• Control + w: Forward SIGCONT to the underlying php process
• Control + y: toggle the silent mode - trace are no longer output on stderr, the script run quicker
• Control + u: toggle the argument / return value pretty dump, script run quicker

Others

php8trace.sh is a pure bash wrapper, but its kinda hard to use

• The stdout / stderr - shell pipe redirect does not work properly because the php process is started in background. To create a log file the easiest way would seem to use the script command
• When the PHP process die, the user is left inside a subshell