apache_mod_perl-108~358::mod_perl-2.0.7::docs::api::APR:UsertContributed Perl Doapache_mod_perl-108~358::mod_perl-2.0.7::docs::api::APR::Status(3)

NAME

       APR::Status - Perl Interface to the APR_STATUS_IS_* macros

Synopsis
	 use APR::Status ();
	 eval { $obj->mp_method() };
	 if ($@ && $ref $@ eq 'APR::Error' && APR::Status::is_EAGAIN($@)) {
	     # APR_STATUS_IS_EAGAIN(s) of apr_errno.h is satisfied
	 }

Description
       An interface to apr_errno.h composite error codes.

       As discussed in the "APR::Error" manpage, it is possible to handle APR/Apache/mod_perl exceptions in the following way:

	 eval { $obj->mp_method() };
	 if ($@ && $ref $@ eq 'APR::Error' && $@ == $some_code)
	     warn "handled exception: $@";
	 }

       However, in cases where $some_code is an APR::Const constant, there may be more than one condition satisfying the intent of this exception.
       For this purpose the APR C library provides in apr_errno.h a series of macros, "APR_STATUS_IS_*", which are the recommended way to check
       for such conditions. For example, the "APR_STATUS_IS_EAGAIN" macro is defined as

	 #define APR_STATUS_IS_EAGAIN(s)	 ((s) == APR_EAGAIN 
			 || (s) == APR_OS_START_SYSERR + ERROR_NO_DATA 
			 || (s) == APR_OS_START_SYSERR + SOCEWOULDBLOCK 
			 || (s) == APR_OS_START_SYSERR + ERROR_LOCK_VIOLATION)

       The purpose of "APR::Status" is to provide functions corresponding to these macros.

Functions
   "is_EACCES"
       Check if the error is matching "EACCES" and its variants (corresponds to the "APR_STATUS_IS_EACCES" macro).

	 $status = APR::Status::is_EACCES($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       An example of using "is_EACCES" is when reading the contents of a file where access may be forbidden:

	 eval { $obj->slurp_filename(0) };
	 if ($@) {
	     return Apache2::Const::FORBIDDEN
		 if ref $@ eq 'APR::Error' && APR::Status::is_EACCES($@);
	     die $@;
	  }

       Due to possible variants in conditions matching "EACCES", the use of this function is recommended for checking error codes against this
       value, rather than just using "APR::Const::EACCES" directly.

   "is_EAGAIN"
       Check if the error is matching "EAGAIN" and its variants (corresponds to the "APR_STATUS_IS_EAGAIN" macro).

	 $status = APR::Status::is_EAGAIN($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       For example, here is how you may want to handle socket read exceptions and do retries:

	 use APR::Status ();
	 # ....
	 my $tries = 0;
	 my $buffer;
	 RETRY: my $rlen = eval { $socket->recv($buffer, SIZE) };
	 if ($@ && ref($@) && APR::Status::is_EAGAIN($@)) {
	     if ($tries++ < 3) {
		 goto RETRY;
	     }
	     else {
		 # do something else
	     }
	 }
	 else {
	     die "eval block has failed: $@";
	 }

       Notice that just checking against "APR::Const::EAGAIN" may work on some Unices, but then it will certainly break on win32. Thefore make
       sure to use this macro and not "APR::Const::EAGAIN" unless you know what you are doing.

   "is_ENOENT"
       Check if the error is matching "ENOENT" and its variants (corresponds to the "APR_STATUS_IS_ENOENT" macro).

	 $status = APR::Status::is_ENOENT($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       An example of using "is_ENOENT" is when reading the contents of a file which may not exist:

	 eval { $obj->slurp_filename(0) };
	 if ($@) {
	     return Apache2::Const::NOT_FOUND
		 if ref $@ eq 'APR::Error' && APR::Status::is_ENOENT($@);
	     die $@;
	 }

       Due to possible variants in conditions matching "ENOENT", the use of this function is recommended for checking error codes against this
       value, rather than just using "APR::Const::ENOENT" directly.

   "is_EOF"
       Check if the error is matching "EOF" and its variants (corresponds to the "APR_STATUS_IS_EOF" macro).

	 $status = APR::Status::is_EOF($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       Due to possible variants in conditions matching "EOF", the use of this function is recommended for checking error codes against this value,
       rather than just using "APR::Const::EOF" directly.

   "is_ECONNABORTED"
       Check if the error is matching "ECONNABORTED" and its variants (corresponds to the "APR_STATUS_IS_ECONNABORTED" macro).

	 $status = APR::Status::is_ECONNABORTED($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       Due to possible variants in conditions matching "ECONNABORTED", the use of this function is recommended for checking error codes against
       this value, rather than just using "APR::Const::ECONNABORTED" directly.

   "is_ECONNRESET"
       Check if the error is matching "ECONNRESET" and its variants (corresponds to the "APR_STATUS_IS_ECONNRESET" macro).

	 $status = APR::Status::is_ECONNRESET($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       Due to possible variants in conditions matching "ECONNRESET", the use of this function is recommended for checking error codes against this
       value, rather than just using "APR::Const::ECONNRESET" directly.

   "is_TIMEUP"
       Check if the error is matching "TIMEUP" and its variants (corresponds to the "APR_STATUS_IS_TIMEUP" macro).

	 $status = APR::Status::is_TIMEUP($error_code);

       arg1: $error_code (integer or "APR::Error object" )
	   The error code or to check, normally $@ blessed into "APR::Error object".

       ret: $status ( boolean )
       since: 2.0.00

       Due to possible variants in conditions matching "TIMEUP", the use of this function is recommended for checking error codes against this
       value, rather than just using "APR::Const::TIMEUP" directly.

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.

perl v5.16.2							    2011-02-07	apache_mod_perl-108~358::mod_perl-2.0.7::docs::api::APR::Status(3)