Programming PHP

Any number of these options can be ORed together, so that errors in each of the levels are
reported. For example, the following code turns off user errors and warnings, performs
some actions, then restores the original level:
escapeshellarg
string escapeshellarg(string argument)
Properly escapes argument so it can be used as a safe argument to a shell function. When
directly passing user input (such as from forms) to a shell command, you should use this
function to escape the data to ensure that the argument isn’t a security risk.
escapeshellcmd
string escapeshellcmd(string command)
Escapes any characters in command that could cause a shell command to run additional
commands. When directly passing user input (such as from forms) to the exec( ) or
system( ) functions, you should use this function to escape the data to ensure that the argument
isn’t a security risk.
exec
string exec(string command[, array output[, int return]])
Executes command via the shell and returns the last line of output from the command’s
result. If output is specified, it is filled with the lines returned by the command. If return is
specified, it is set to the return status of the command.
If you want to have the results of the command output into the PHP page, use passthru( ).
exp
E_CORE_WARNING Warnings generated internally by PHP
E_COMPILE_ERROR Errors generated internally by the Zend scripting engine
E_COMPILE_WARNING Warnings generated internally by the Zend scripting engine
E_USER_ERROR Runtime errors generated by a call to trigger_error( )
E_USER_WARNING Runtime warnings generated by a call to trigger_error( )
E_ALL All of the above options
double exp(double number)
Returns e raised to the number power.
396 | Appendix A: Function Reference
This is the Title of the Book, eMatter Edition
Copyright © 2002 O’Reilly & Associates, Inc. All rights reserved.