Differences to other SAPIs

Remarkable differences of the CLI SAPI compared
to other SAPIs:

• Unlike the CGI SAPI, no
  headers are written to the output.

  Though the CGI SAPI provides
  a way to suppress HTTP headers, there’s no equivalent switch to
  enable them in the CLI SAPI.

  CLI is started up in
  quiet mode by default, though the -q and –no-header switches are kept for
  compatibility so that it is possible to use older CGI scripts.

  It does not change the working directory to that of
  the script. (-C and
  –no-chdir switches kept
  for compatibility)

  Plain text error messages (no HTML formatting).

• There are certain php.ini directives which are overridden by the
  CLI
  SAPI because
  they do not make sense in shell environments:

  Overridden php.ini
  directives

  Directive	CLI SAPI default value	Comment
  html_errors	FALSE	Defaults to FALSE, as it can be quite hard to read error messages in the shell enviroment when they are cluttered up with uninterpreted HTML tags.
  implicit_flush	TRUE	In a shell environment, it is usually desirable for output, such as from print, echo and friends, to be displayed immediately, and not held in a buffer. Nonetheless, it is still possible to use output buffering to defer or manipulate standard output.
  max_execution_time	0 (unlimited)	PHP in a shell environment tends to be used for a much more diverse range of purposes than typical Web-based scripts, and as these can be very long-running, the maximum execution time is set to unlimited.
  register_argc_argv	TRUE	Setting this to TRUE means that scripts executed via the CLI SAPI always have access to argc (number of arguments passed to the application) and argv (array of the actual arguments). The PHP variables $argc and $argv are automatically set to the appropriate values when using the CLI SAPI. These values can also be found in the $_SERVER array, for example: $_SERVER[‘argv’].
  output_buffering	FALSE	Although the php.ini setting is hardcoded to FALSE, the Output buffering functions are available.
  max_input_time	FALSE	The PHP CLI does not support GET, POST or file uploads.

  Note:

  These directives cannot be initialized with another
  value from the configuration file php.ini or a custom one (if specified). This
  limitation is because the values are applied after all
  configuration files have been parsed. However, their values can be
  changed during runtime (although this is not sensible for all of
  them, such as register_argc_argv).

  Note:

  It is recommended to set ignore_user_abort for command line scripts. See
  ignore_user_abort() for more
  information.

• To ease working in the shell environment, a number
  of constants are defined for I/O streams
  .

• The CLI SAPI does
  not change the current directory to the
  directory of the executed script.

  Example #1 Example showing the difference to the
  CGI
  SAPI:

  <?php
// Our simple test application named test.php
echo getcwd(), "\n";
?>

  When using the CGI version, the output
  is:

  $ pwd
  /tmp
  
  $ php -q another_directory/test.php
  /tmp/another_directory
  

  This clearly shows that PHP changes its current directory to the
  one of the executed script.

  Using the CLI SAPI
  yields:

  $ pwd
  /tmp
  
  $ php -f another_directory/test.php
  /tmp
  

  This allows greater flexibility when writing shell tools in
  PHP.

  Note:

  The CGI SAPI supports
  this CLI SAPI behaviour
  by means of the -C switch
  when run from the command line.