Список php functions, отключенные на серверах по меркам безопасности:
apache_note
apache_setenv
chgrp
closelog
debugger_off
debugger_on
define_sys
define_syslog_variables
diskfreespace
dl
escapeshellarg
escapeshellcmd
exec
getmypid
getmyuid
ini_restore
leak
listen
openlog
passthru
pclose
pcntl_alarm
pcntl_exec
pcntl_fork
pcntl_getpriority
pcntl_get_last_error
pcntl_setpriority
pcntl_signal
pcntl_signal_dispatch
pcntl_sigprocmask
pcntl_sigtimedwait
pcntl_sigwaitinfo
pcntl_strerror
pcntl_wait
pcntl_waitpid
pcntl_wexitstatus
pcntl_wifexited
pcntl_wifsignaled
pcntl_wifstopped
pcntl_wstopsig
pcntl_wtermsig
php_uname
popen
posix
posix_ctermid
posix_getcwd
posix_getegid
posix_geteuid
posix_getgid
posix_getgrgid
posix_getgrnam
posix_getgroups
posix_getlogin
posix_getpgid
posix_getpgrp
posix_getpid
posix_getpwnam
posix_getpwuid
posix_getrlimit
posix_getsid
posix_getuid
posix_isatty
posix_kill
posix_mkfifo
posix_setegid
posix_seteuid
posix_setgid
posix_setpgid
posix_setsid
posix_setuid
posix_times
posix_ttyname
posix_uname
proc_close
proc_get_status
proc_nice
proc_open
proc_terminate
shell_exec
show_source
syslog
system
url_exec
_getppid
pcntl extension is usually disabled in PHP, so may be you can skip its functions in your list. posix extension is usually enabled, but you can disable it, recompiled PHP with an option –disable-posix
Ready-to-use disable_functions for copy&paste:
disable_functions=apache_note,apache_setenv,chgrp,closelog,debugger_off,debugger_on,define_sys,define_syslog_variables,diskfreespace,dl,escapeshellarg,escapeshellcmd,exec,getmypid,getmyuid,ini_restore,leak,listen,openlog,passthru,pclose,pcntl_alarm,pcntl_exec,pcntl_fork,pcntl_getpriority,pcntl_get_last_error,pcntl_setpriority,pcntl_signal,pcntl_signal_dispatch,pcntl_sigprocmask,pcntl_sigtimedwait,pcntl_sigwaitinfo,pcntl_strerror,pcntl_wait,pcntl_waitpid,pcntl_wexitstatus,pcntl_wifexited,pcntl_wifsignaled,pcntl_wifstopped,pcntl_wstopsig,pcntl_wtermsig,php_uname,popen,posix,posix_ctermid,posix_getcwd,posix_getegid,posix_geteuid,posix_getgid,posix_getgrgid,posix_getgrnam,posix_getgroups,posix_getlogin,posix_getpgid,posix_getpgrp,posix_getpid,posix_getpwnam,posix_getpwuid,posix_getrlimit,posix_getsid,posix_getuid,posix_isatty,posix_kill,posix_mkfifo,posix_setegid,posix_seteuid,posix_setgid,posix_setpgid,posix_setsid,posix_setuid,posix_times,posix_ttyname,posix_uname,proc_close,proc_get_status,proc_nice,proc_open,proc_terminate,shell_exec,show_source,syslog,system,url_exec,_getppid