apd_breakpoint Stops the interpreter and waits on a CR from the socket boolapd_breakpoint intdebug_level This can be used to stop the running of your script, and await responses on the connected socket. To step the program, just send enter (a blank line), or enter a php command to be executed. A typical session using tcplisten would look like this. \n statement: /home/alan/Projects/project2/test.php:8 >\n statement: /home/alan/Projects/project2/test.php:8 >\n statement: /home/alan/Projects/project2/test.php:10 >apd_echo($i); EXEC: apd_echo($i); 0 >apd_echo(serialize(apd_get_active_symbols())); EXEC: apd_echo(serialize(apd_get_active_symbols())); a:47:{i:0;s:4:"PWD";i:1;s:10:"COLORFGBG";i:2;s:11:"XAUTHORITY";i:3;s:14:" COLORTERM_BCE";i:4;s:9:"WINDOWID";i:5;s:14:"ETERM_VERSION";i:6;s:16:"SE SSION_MANAGER";i:7;s:4:"PS1";i:8;s:11:"GDMSESSION";i:9;s:5:"USER";i:10;s:5:" MAIL";i:11;s:7:"OLDPWD";i:12;s:5:"LANG";i:13;s:10:"COLORTERM";i:14;s:8:"DISP LAY";i:15;s:8:"LOGNAME";i:16;s:6:" >apd_echo(system('ls /home/mydir')); ........ >apd_continue(0); ]]>