Apache2::RequestIO(3) Perl API for Apache request record IO

Synopsis

  use Apache2::RequestIO ();
  
  $rc = $r->discard_request_body();
  
  $r->print("foo", "bar");
  $r->puts("foo", "bar"); # same as print, but no flushing
  $r->printf("%s $d", "foo", 5);
  
  $r->read($buffer, $len);
  
  $r->rflush();
  
  $r->sendfile($filename);
  
  $r->write("foobartarcar", 3, 5);

Description

"Apache2::RequestIO" provides the API to perform IO on the Apache request object.

API

"Apache2::RequestIO" provides the following functions and/or methods:

discard_request_body

In HTTP/1.1, any method can have a body. However, most GET handlers wouldn't know what to do with a request body if they received one. This helper routine tests for and reads any message body in the request, simply discarding whatever it receives. We need to do this because failing to read the request body would cause it to be interpreted as the next request on a persistent connection. 

  $rc = $r->discard_request_body();
obj: $r ( "Apache2::RequestRec object" )
The current request
ret: $rc ( integer )
"APR::Const status constant" if request is malformed, "Apache2::Const::OK" otherwise.
since: 2.0.00

Since we return an error status if the request is malformed, this routine should be called at the beginning of a no-body handler, e.g., 

   use Apache2::Const -compile => qw(OK);
   $rc = $r->discard_request_body;
   return $rc if $rc != Apache2::Const::OK;

print

Send data to the client. 

  $cnt = $r->print(@msg);
obj: $r ( "Apache2::RequestRec object" )
arg1: @msg ( ARRAY )
Data to send
ret: $cnt ( number )
How many bytes were sent (or buffered). If zero bytes were sent, "print" will return 0E0, or ``zero but true,'' which will still evaluate to 0 in a numerical context.
excpt: "APR::Error"
since: 2.0.00

The data is flushed only if STDOUT stream's $| is true. Otherwise it's buffered up to the size of the buffer, flushing only excessive data.

printf

Format and send data to the client (same as "printf"). 

  $cnt = $r->printf($format, @args);
obj: $r ( "Apache2::RequestRec object" )
arg1: $format ( string )
Format string, as in the Perl core "printf" function.
arg2: @args ( ARRAY )
Arguments to be formatted, as in the Perl core "printf" function.
ret: $cnt ( number )
How many bytes were sent (or buffered)
excpt: "APR::Error"
since: 2.0.00

The data is flushed only if STDOUT stream's $| is true. Otherwise it's buffered up to the size of the buffer, flushing only excessive data.

puts

Send data to the client 

  $cnt = $r->puts(@msg);
obj: $r ( "Apache2::RequestRec object" )
arg1: @msg ( ARRAY )
Data to send
ret: $cnt ( number )
How many bytes were sent (or buffered)
excpt: "APR::Error"
since: 2.0.00

"puts()" is similar to "print()", but it won't attempt to flush data, no matter what the value of STDOUT stream's $| is. Therefore assuming that STDOUT stream's $| is true, this method should be a tiny bit faster than "print()", especially if small strings are printed.

read

Read data from the client. 

  $cnt = $r->read($buffer, $len);
  $cnt = $r->read($buffer, $len, $offset);
obj: $r ( "Apache2::RequestRec object" )
arg1: $buffer ( SCALAR )
The buffer to populate with the read data
arg2: $len ( number )
How many bytes to attempt to read
opt arg3: $offset ( number )
If a non-zero $offset is specified, the read data will be placed at that offset in the $buffer.

META: negative offset and \0 padding are not supported at the moment

ret: $cnt ( number )
How many characters were actually read
excpt: "APR::Error"
since: 2.0.00

This method shares a lot of similarities with the Perl core "read()" function. The main difference in the error handling, which is done via "APR::Error exceptions"

rflush

Flush any buffered data to the client. 

  $r->rflush();
obj: $r ( "Apache2::RequestRec object" )
ret: no return value
since: 2.0.00

Unless STDOUT stream's $| is false, data sent via "$r->print()" is buffered. This method flushes that data to the client.

sendfile

Send a file or a part of it 

  $rc = $r->sendfile($filename);
  $rc = $r->sendfile($filename, $offset);
  $rc = $r->sendfile($filename, $offset, $len);
obj: $r ( "Apache2::RequestRec object" )
arg1: $filename ( string )
The full path to the file (using "/" on all systems)
opt arg2: $offset ( integer )
Offset into the file to start sending.

No offset is used if $offset is not specified.

opt arg3: $len ( integer )
How many bytes to send.

If not specified the whole file is sent (or a part of it, if $offset if specified)

ret: $rc ( "APR::Const status constant" )
On success, "APR::Const::SUCCESS" is returned.

In case of a failure --- a failure code is returned, in which case normally it should be returned to the caller.

excpt: "APR::Error"
Exceptions are thrown only when this function is called in the VOID context. So if you don't want to handle the errors, just don't ask for a return value and the function will handle all the errors on its own.
since: 2.0.00

write

Send partial string to the client 

  $cnt = $r->write($buffer);
  $cnt = $r->write($buffer, $len);
  $cnt = $r->write($buffer, $len, $offset);
obj: $r ( "Apache2::RequestRec object" )
arg1: $buffer ( SCALAR )
The string with data
opt arg2: $len ( SCALAR )
How many bytes to send. If not specified, or -1 is specified, all the data in $buffer (or starting from $offset) will be sent.
opt arg3: $offset ( number )
Offset into the $buffer string.
ret: $cnt ( number )
How many bytes were sent (or buffered)
excpt: "APR::Error"
since: 2.0.00

Examples:

Assuming that we have a string: 

  $string = "123456789";

Then: 

  $r->write($string);

sends: 

  123456789

Whereas: 

  $r->write($string, 3);

sends: 

  123

And: 

  $r->write($string, 3, 5);

sends: 

  678

Finally: 

  $r->write($string, -1, 5);

sends: 

  6789

TIE Interface

The TIE interface implementation. This interface is used for HTTP request handlers, when running under "SetHandler perl-script" and Perl doesn't have perlio enabled.

See the perltie manpage for more information.

BINMODE

since: 2.0.00

NoOP

See the binmode Perl entry in the perlfunc manpage

CLOSE

since: 2.0.00

NoOP

See the close Perl entry in the perlfunc manpage

FILENO

since: 2.0.00

See the fileno Perl entry in the perlfunc manpage

GETC

since: 2.0.00

See the getc Perl entry in the perlfunc manpage

OPEN

since: 2.0.00

See the open Perl entry in the perlfunc manpage

PRINT

since: 2.0.00

See the print Perl entry in the perlfunc manpage

PRINTF

since: 2.0.00

See the printf Perl entry in the perlfunc manpage

READ

since: 2.0.00

See the read Perl entry in the perlfunc manpage

TIEHANDLE

since: 2.0.00

See the tie Perl entry in the perlfunc manpage

UNTIE

since: 2.0.00

NoOP

See the untie Perl entry in the perlfunc manpage

WRITE

since: 2.0.00

See the write Perl entry in the perlfunc manpage

Deprecated API

The following methods are deprecated, Apache plans to remove those in the future, therefore avoid using them.

get_client_block

This method is deprecated since the C implementation is buggy and we don't want you to use it at all. Instead use the plain "$r->read()".

setup_client_block

This method is deprecated since "$r->get_client_block" is deprecated.

should_client_block

This method is deprecated since "$r->get_client_block" is deprecated.

See Also

mod_perl 2.0 documentation.

Copyright

mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.

Authors

The mod_perl development team and numerous contributors.

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