Apache2::RequestUtil - Perl API for Apache request record utils
use Apache2::RequestUtil (); # add httpd config dynamically $r->add_config(['require valid-user']); # dump the request object as a string print $r->as_string(); # default content_type $content_type = $r->default_type(); # get PerlSetVar/PerlAddVar values @values = $r->dir_config->get($key); # get server docroot $docroot = $r->document_root(); # set server docroot $r->document_root($new_root); # what are the registered perl handlers for a given phase my @handlers = @{ $r->get_handlers('PerlResponseHandler') || [] }; # push a new handler for a given phase $r->push_handlers(PerlCleanupHandler => \&handler); # set handlers for a given phase (resetting previous values) $r->set_handlers(PerlCleanupHandler => []); # what's the request body limit $limit = $r->get_limit_req_body(); # server and port names $server = $r->get_server_name(); $port = $r->get_server_port(); # what string Apache is going to send for a given status code $status_line = Apache2::RequestUtil::get_status_line(404); # are we in the main request? $is_initial = $r->is_initial_req(); # directory level PerlOptions flags lookup $r->subprocess_env unless $r->is_perl_option_enabled('SetupEnv'); # current <Location> value $location = $r->location(); # merge a <Location> container in a request object $r->location_merge($location); # create a new Apache2::RequestRec object $r = Apache2::RequestRec->new($c); # tell the client not to cache the response $r->no_cache($boolean); # share perl objects by reference like $r->notes $r->pnotes($key => [$obj1, $obj2]); # get HTML signature $sig = $r->psignature($prefix); # get the global request object (requires PerlOptions +GlobalRequest) $r = Apache2::RequestUtil->request; # insert auth credentials into the request as if the client did that $r->set_basic_credentials($username, $password); # slurp the contents of $r->filename my $content = ${ $r->slurp_filename() }; # terminate the current child after this request $r->child_terminate();
Apache2::RequestUtil provides the Apache request object utilities API.
Apache2::RequestUtil
add_config
Dynamically add Apache configuration at request processing runtime:
$r->add_config($lines); $r->add_config($lines, $override); $r->add_config($lines, $override, $path); $r->add_config($lines, $override, $path, $override_opts);
Configuration directives are processed as if given in a <Location> block.
<Location>
$r
Apache2::RequestRec object
$lines
An ARRAY reference containing configuration lines per element, without the new line terminators.
$override
Apache2::Const override constant
Which allow-override bits are set
Default value is: Apache2::Const::OR_AUTHCFG
Apache2::Const::OR_AUTHCFG
$path
Set the Apache2::CmdParms object path component. This is the path of the <Location> block. Some directives need this, for example ProxyPassReverse.
Apache2::CmdParms object
path
ProxyPassReverse
If an empty string is passed a NULL pointer is passed further at C-level. This is necessary to make something like this work:
NULL
$r->add_config( [ '<Directory />', 'AllowOverride Options AuthConfig', '</Directory>', ], ~0, '' );
Note: AllowOverride is valid only in directory context.
AllowOverride
Caution: Some directives need a non-empty path otherwise they cause segfaults. Thus, use the empty path with caution.
Default value is: /
/
$override_opts
Apache2::Const options constant
Apache limits the applicable directives in certain situations with AllowOverride. With Apache 2.2 comes the possibility to enable or disable single options, for example
AllowOverride AuthConfig Options=ExecCGI,Indexes
Internally, this directive is parsed into 2 bit fields that are represented by the $override and $override_opts parameters to add_config. The above example is parsed into an $override with 2 bits set, one for AuthConfig the other for Options and an $override_opts with 2 bits set for ExecCGI and Indexes.
AuthConfig
Options
When applying other directives, for example AuthType or Options the appropriate bits in $override must be set. For the Options directive additionally $override_opts bits must be set.
AuthType
The $override and $override_opts parameters to add_config are valid while applying $lines.
$override_opts is new in Apache 2.2. The mod_perl implementation for Apache 2.0 lets you pass the parameter but ignores it.
Default for $override_opts is: Apache2::Const::OPT_UNSET | Apache2::Const::OPT_ALL | Apache2::Const::OPT_INCNOEXEC | Apache2::Const::OPT_SYM_OWNER | Apache2::Const::OPT_MULTI
Apache2::Const::OPT_UNSET
Apache2::Const::OPT_ALL
Apache2::Const::OPT_INCNOEXEC
Apache2::Const::OPT_SYM_OWNER
Apache2::Const::OPT_MULTI
That means, all options are allowed.
See also: $s->add_config
$s->add_config
For example:
use Apache2::RequestUtil (); use Apache2::Access (); $r->add_config(['require valid-user']); # this regards the current AllowOverride setting $r->add_config(['AuthName secret', 'AuthType Basic', 'Options ExecCGI'], $r->allow_override, $path, $r->allow_override_opts);
as_string
Dump the request object as a string
$dump = $r->as_string();
$dump
Dumps various request and response headers (mainly useful for debugging)
child_terminate
Terminate the current worker process as soon as the current request is over
$r->child_terminate();
This method is not supported in threaded MPMs
default_type
Retrieve the value of the DefaultType directive for the current request. If not set text/plain is returned.
text/plain
$content_type = $r->default_type();
The current request
$content_type
The default type
httpd
dir_config
$r->dir_config() provides an interface for the per-directory variable specified by the PerlSetVar and PerlAddVar directives, and also can be manipulated via the APR::Table methods.
$r->dir_config()
PerlSetVar
PerlAddVar
APR::Table
$table = $r->dir_config(); $value = $r->dir_config($key); @values = $r->dir_config->get($key); $r->dir_config($key, $val);
$key
Key string
$val
Value string
Depends on the passed arguments, see further discussion
The keys are case-insensitive.
$apr_table = $r->dir_config();
dir_config() called in a scalar context without the $key argument returns a HASH reference blessed into the APR::Table class. This object can be manipulated via the APR::Table methods. For available methods see the APR::Table manpage.
$value = $r->dir_config($key);
If the $key argument is passed in the scalar context only a single value will be returned. Since the table preserves the insertion order, if there is more than one value for the same key, the oldest value assosiated with the desired key is returned. Calling in the scalar context is also much faster, as it'll stop searching the table as soon as the first match happens.
@values = $r->dir_config->get($key);
To receive a list of values you must use get() method from the APR::Table class.
get()
$r->dir_config($key => $val);
If the $key and the $val arguments are used, the set() operation will happen: all existing values associated with the key $key (and the key itself) will be deleted and $value will be placed instead.
$value
$r->dir_config($key => undef);
If $val is undef the unset() operation will happen: all existing values associated with the key $key (and the key itself) will be deleted.
document_root
Retrieve the document root for this server
$docroot = $r->document_root(); $docroot = $r->document_root($new_root);
$new_root
Sets the document root to a new value only for the duration of the current request.
Note the limited functionality under threaded MPMs.
$docroot
The document root
get_handlers
Returns a reference to a list of handlers enabled for a given phase.
$handlers_list = $r->get_handlers($hook_name);
$hook_name
a string representing the phase to handle (e.g. PerlLogHandler)
PerlLogHandler
$handlers_list
a list of handler subroutines CODE references
A list of handlers configured to run at the response phase:
my @handlers = @{ $r->get_handlers('PerlResponseHandler') || [] };
get_limit_req_body
Return the limit on bytes in request msg body
$limit = $r->get_limit_req_body();
$limit
the maximum number of bytes in the request msg body
get_server_name
Get the current request's server name
$server = $r->get_server_name();
$server
the server name
For example, consruct a hostport string:
use Apache2::RequestUtil (); my $hostport = join ':', $r->get_server_name, $r->get_server_port;
get_server_port
Get the current server port
$port = $r->get_server_port();
$port
The server's port number
get_status_line
Return the Status-Line for a given status code (excluding the HTTP-Version field).
Status-Line
$status_line = Apache2::RequestUtil::get_status_line($status);
$status
The HTTP status code
$status_line
The Status-Line
If an invalid or unknown status code is passed, "500 Internal Server Error" will be returned.
"500 Internal Server Error"
use Apache2::RequestUtil (); print Apache2::RequestUtil::get_status_line(400);
will print:
400 Bad Request
is_initial_req
Determine whether the current request is the main request or a sub-request
$is_initial = $r->is_initial_req();
A request or a sub-request object
$is_initial
If true -- it's the main request, otherwise it's a sub-request
is_perl_option_enabled
check whether a directory level PerlOptions flag is enabled or not.
PerlOptions
$result = $r->is_perl_option_enabled($flag);
$flag
$result
For example to check whether the SetupEnv option is enabled for the current request (which can be disabled with PerlOptions -SetupEnv) and populate the environment variables table if disabled:
SetupEnv
PerlOptions -SetupEnv
$r->subprocess_env unless $r->is_perl_option_enabled('SetupEnv');
See also: PerlOptions and the equivalent function for server level PerlOptions flags.
location
Get the path of the <Location> section from which the current Perl*Handler is being called.
Perl*Handler
$location = $r->location();
$location
location_merge
Merge a given <Location> container into the current request object:
$ret = $r->location_merge($location);
The argument in a <Location> section. For example to merge a container:
<Location /foo> ... </Location>
that argument will be /foo
$ret
a true value if the merge was successful (i.e. the request $location match was found), otherwise false.
Useful for insertion of a configuration section into a custom Apache2::RequestRec object, created via the Apache2::RequestRec->new() method. See for example the Command Server protocol example.
Apache2::RequestRec
Apache2::RequestRec->new()
new
Create a new Apache2::RequestRec object.
$r = Apache2::RequestRec->new($c); $r = Apache2::RequestRec->new($c, $pool);
Apache2::RequestRec class name
$c
Apache2::Connection object
$pool
If no $pool argument is passed, $c->pool is used. That means that the created Apache2::RequestRec object will be valid as long as the connection object is valid.
$c->pool
It's possible to reuse the HTTP framework features outside the familiar HTTP request cycle. It's possible to write your own full or partial HTTP implementation without needing a running Apache server. You will need the Apache2::RequestRec object in order to be able to reuse the rich functionality supplied via this object.
See for example the Command Server protocol example which reuses HTTP AAA model under non-HTTP protocol.
no_cache
Add/remove cache control headers:
$prev_no_cache = $r->no_cache($boolean);
$boolean
A true value sets the no_cache request record member to a true value and inserts:
Pragma: no-cache Cache-control: no-cache
into the response headers, indicating that the data being returned is volatile and the client should not cache it.
A false value unsets the no_cache request record member and the mentioned headers if they were previously set.
$prev_no_cache
Should you care, the no_cache request record member value prior to the change is returned.
This method should be invoked before any response data has been sent out.
pnotes
Share Perl variables between Perl HTTP handlers
# to share variables by value and not reference, $val should be a lexical. $old_val = $r->pnotes($key => $val); $val = $r->pnotes($key); $hash_ref = $r->pnotes();
Note: sharing variables really means it. The variable is not copied. Only its reference count is incremented. If it is changed after being put in pnotes that change also affects the stored value. The following example illustrates the effect:
my $v=1; my $v=1; $r->pnotes( 'v'=>$v ); $r->pnotes->{v}=$v; $v++; $v++; my $x=$r->pnotes('v'); my $x=$r->pnotes->{v};
In both cases $x is 2 not 1. See also Apache2::SafePnotes on CPAN.
$x
2
1
Apache2::SafePnotes
There has been a lot of discussion advocating for pnotes sharing variables by value and not reference. Sharing by reference can create 'spooky action at a distance' effects when the sharing is assumed to share a copy of the value. Tim Bunce offers the following summary and suggestion for sharing by value.
What's wrong with this code:
sub foo { my ($r, $status, $why) = @_; $r->pnotes('foo', ($why) ? "$status:$why" : $status); return; }
Nothing, except it doesn't work as expected due to this pnotes bug: If the same code is called in a sub-request then the pnote of $r->prev is magically updated at a distance to the same value!
Try explain why that is to anyone not deeply familar with perl internals!
The fix is to avoid pnotes taking a ref to the invisible op_targ embededed in the code by passing a simple lexical variable as the actual argument. That can be done in-line like this:
sub mark_as_internally_redirected { my ($r, $status, $why) = @_; $r->pnotes('foo', my $tmp = (($why) ? "$status:$why" : $status)); return; }
A key value
Any scalar value (e.g. a reference to an array)
if both, $key and $val are passed the previous value for $key is returned if such existed, otherwise undef is returned.
undef
if only $key is passed, the current value for the given key is returned.
if no arguments are passed, a hash reference is returned, which can then be directly accessed without going through the pnotes() interface.
pnotes()
This method provides functionality similar to (Apache2::RequestRec::notes), but values can be any Perl variables. That also means that it can be used only between Perl modules.
Apache2::RequestRec::notes
The values get reset automatically at the end of each HTTP request.
Examples:
Set a key/value pair:
$r->pnotes(foo => [1..5]);
Get the value:
$val = $r->pnotes("foo");
$val now contains an array ref containing 5 elements (1..5).
1..5
Now change the existing value:
$old_val = $r->pnotes(foo => ['a'..'c']); $val = $r->pnotes("foo");
$old_val now contains an array ref with 5 elements (1..5) and $val contains an array ref with 3 elements 'a', 'b', 'c'.
$old_val
'a'
'b'
'c'
Alternatively you can access the hash reference with all pnotes values:
$pnotes = $r->pnotes;
Now we can read what's in there for the key foo:
$val = $pnotes->{foo};
and as before $val still gives us an array ref with 3 elements 'a', 'b', 'c'.
Now we can add elements to it:
push @{ $pnotes{foo} }, 'd'..'f';
and we can try to retrieve them using the hash and non-hash API:
$val1 = $pnotes{foo}; $val2 = $r->pnotes("foo");
Both $val1 and $val2 contain an array ref with 6 elements (letters 'a' to 'f').
$val1
$val2
Finally to reset an entry you could just assign undef as a value:
$r->pnotes(foo => undef);
but the entry for the key foo still remains with the value undef. If you really want to completely remove it, use the hash interface:
delete $r->pnotes->{foo};
psignature
Get HTML describing the address and (optionally) admin of the server.
$sig = $r->psignature($prefix);
$prefix
Text which is prepended to the return value
$sig
HTML text describing the server. Note that depending on the value of the ServerSignature directive, the function may return the address, including the admin information or nothing at all.
ServerSignature
request
Get/set the ( Apache2::RequestRec object ) object for the current request.
$r = Apache2::RequestUtil->request; Apache2::RequestUtil->request($new_r);
Apache2
The Apache class name
$new_r
The get-able part of this method is only available if PerlOptions +GlobalRequest is in effect or if Apache2->request($new_r) was called earlier. So instead of setting PerlOptions +GlobalRequest, one can set the global request from within the handler.
PerlOptions +GlobalRequest
Apache2->request($new_r)
push_handlers
Add one or more handlers to a list of handlers to be called for a given phase.
$ok = $r->push_handlers($hook_name => \&handler); $ok = $r->push_handlers($hook_name => ['Foo::Bar::handler', \&handler2]);
the phase to add the handlers to
$handlers
a single handler CODE reference or just a name of the subroutine (fully qualified unless defined in the current package).
if more than one passed, use a reference to an array of CODE refs and/or subroutine names.
$ok
returns a true value on success, otherwise a false value
Note that to push input/output filters you have to use Apache2::Filter methods: add_input_filter and add_output_filter.
Apache2::Filter
add_input_filter
add_output_filter
A single handler:
$r->push_handlers(PerlResponseHandler => \&handler);
Multiple handlers:
$r->push_handlers(PerlFixupHandler => ['Foo::Bar::handler', \&handler2]);
Anonymous functions:
$r->push_handlers(PerlLogHandler => sub { return Apache2::Const::OK });
set_basic_credentials
Populate the incoming request headers table (headers_in) with authentication headers for Basic Authorization as if the client has submitted those in first place:
headers_in
$r->set_basic_credentials($username, $password);
$username
$password
set_handlers
Set a list of handlers to be called for a given phase. Any previously set handlers are forgotten.
$ok = $r->set_handlers($hook_name => \&handler); $ok = $r->set_handlers($hook_name => ['Foo::Bar::handler', \&handler2]); $ok = $r->set_handlers($hook_name => []); $ok = $r->set_handlers($hook_name => undef);
the phase to set the handlers in
a reference to a single handler CODE reference or just a name of the subroutine (fully qualified unless defined in the current package).
if the argument is undef or [] the list of handlers is reset to zero.
[]
$r->set_handlers(PerlResponseHandler => \&handler);
$r->set_handlers(PerlFixupHandler => ['Foo::Bar::handler', \&handler2]);
$r->set_handlers(PerlLogHandler => sub { return Apache2::Const::OK });
Reset any previously set handlers:
$r->set_handlers(PerlCleanupHandler => []);
or
$r->set_handlers(PerlCleanupHandler => undef);
slurp_filename
Slurp the contents of $r->filename:
$r->filename
$content_ref = $r->slurp_filename($tainted);
$tainted
If the server is run under the tainting mode (-T) which we hope you do, by default the returned data is tainted. If an optional $tainted flag is set to zero, the data will be marked as non-tainted.
-T
Do not set this flag to zero unless you know what you are doing, you may create a security hole in your program if you do. For more information see the perlsec manpage.
If you wonder why this option is available, it is used internally by the ModPerl::Registry handler and friends, because the CGI scripts that it reads are considered safe (you could just as well require() them).
ModPerl::Registry
require()
$content_ref
A reference to a string with the contents
APR::Error
Possible error codes could be: APR::Const::EACCES (permission problems), APR::Const::ENOENT (file not found), and others. For checking such error codes, see the documentation for, for example, APR::Status::is_EACCES and APR::Status::is_ENOENT.
APR::Const::EACCES
APR::Const::ENOENT
APR::Status::is_EACCES
APR::Status::is_ENOENT
Note that if you assign to $r->filename you need to update its stat record.
mod_perl 2.0 documentation.
mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.
The mod_perl development team and numerous contributors.
To install mod_perl2, copy and paste the appropriate command in to your terminal.
cpanm
cpanm mod_perl2
CPAN shell
perl -MCPAN -e shell install mod_perl2
For more information on module installation, please visit the detailed CPAN module installation guide.