How To Make Shell Cant Show File

i setup mod_security and disable this function
system,passthru,exec,popen,proc_close,proc_get_status,proc_nice,proc_open,proc_terminate,shell_exec, highlight_file,pclose,pfsockopen,chmod,debugger_off,debugger_on,leak,ftp_exec,posix_uname,getmyuid,g etmygid,posix_kill,posix_mkfifo,chgrp,listen,define_syslog_variables,posix_getpwuid,get_current_user ,apache_child_terminate,posix_setpgid,posix_setsid,posix_setuid,getservbyport,getservbyname,myshelle xec,escapeshellarg

and now i have good security but i want ask hhow to make shell dosent show any files and also want know how i can change the error pages design like 400 410 for all my servers