apr::status.3

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.\" ========================================================================
.\"
.IX Title "mod_perl-2.0.2::docs::api::APR::Status 3"
.TH mod_perl-2.0.2::docs::api::APR::Status 3 "2005-10-21" "perl v5.10.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
APR::Status \- Perl Interface to the APR_STATUS_IS_* macros
.SH "Synopsis"
.IX Header "Synopsis"
.Vb 5
\&  use APR::Status ();
\&  eval { $obj\->mp_method() };
\&  if ($@ && $ref $@ eq \*(AqAPR::Error\*(Aq && APR::Status::is_EAGAIN($@)) {
\&      # APR_STATUS_IS_EAGAIN(s) of apr_errno.h is satisfied
\&  }
.Ve
.SH "Description"
.IX Header "Description"
An interface to \fIapr_errno.h\fR composite error codes.
.PP
As discussed in the \f(CW\*(C`APR::Error\*(C'\fR
manpage, it is possible to handle APR/Apache/mod_perl exceptions in
the following way:
.PP
.Vb 4
\&  eval { $obj\->mp_method() };
\&  if ($@ && $ref $@ eq \*(AqAPR::Error\*(Aq && $@ == $some_code)
\&      warn "handled exception: $@";
\&  }
.Ve
.PP
However, in cases where \f(CW$some_code\fR is an APR::Const
constant, there may be more than one
condition satisfying the intent of this exception. For this purpose
the \s-1APR\s0 C library provides in \fIapr_errno.h\fR a series of macros,
\&\f(CW\*(C`APR_STATUS_IS_*\*(C'\fR, which are the recommended way to check for such
conditions. For example, the \f(CW\*(C`APR_STATUS_IS_EAGAIN\*(C'\fR macro is defined
as
.PP
.Vb 4
\&  #define APR_STATUS_IS_EAGAIN(s)         ((s) == APR_EAGAIN \e
\&                  || (s) == APR_OS_START_SYSERR + ERROR_NO_DATA \e
\&                  || (s) == APR_OS_START_SYSERR + SOCEWOULDBLOCK \e
\&                  || (s) == APR_OS_START_SYSERR + ERROR_LOCK_VIOLATION)
.Ve
.PP
The purpose of \f(CW\*(C`APR::Status\*(C'\fR is to provide functions corresponding
to these macros.
.SH "Functions"
.IX Header "Functions"
.ie n .Sh """is_EACCES"""
.el .Sh "\f(CWis_EACCES\fP"
.IX Subsection "is_EACCES"
Check if the error is matching \f(CW\*(C`EACCES\*(C'\fR and its variants (corresponds
to the \f(CW\*(C`APR_STATUS_IS_EACCES\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_EACCES($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
An example of using \f(CW\*(C`is_EACCES\*(C'\fR is when reading the contents of a
file where access may be forbidden:
.PP
.Vb 6
\&  eval { $obj\->slurp_filename(0) };
\&  if ($@) {
\&      return Apache2::Const::FORBIDDEN
\&          if ref $@ eq \*(AqAPR::Error\*(Aq && APR::Status::is_EACCES($@);
\&      die $@;
\&   }
.Ve
.PP
Due to possible variants in conditions matching \f(CW\*(C`EACCES\*(C'\fR,
the use of this function is recommended for checking error codes
against this value, rather than just using
\&\f(CW\*(C`APR::Const::EACCES\*(C'\fR
directly.
.ie n .Sh """is_EAGAIN"""
.el .Sh "\f(CWis_EAGAIN\fP"
.IX Subsection "is_EAGAIN"
Check if the error is matching \f(CW\*(C`EAGAIN\*(C'\fR and its variants (corresponds
to the \f(CW\*(C`APR_STATUS_IS_EAGAIN\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_EAGAIN($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
For example, here is how you may want to handle socket read exceptions
and do retries:
.PP
.Vb 10
\&  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: $@";
\&  }
.Ve
.PP
Notice that just checking against
\&\f(CW\*(C`APR::Const::EAGAIN\*(C'\fR
may work on some Unices, but then it will certainly break on
win32. Thefore make sure to use this macro and not
\&\f(CW\*(C`APR::Const::EAGAIN\*(C'\fR unless you know what you are doing.
.ie n .Sh """is_ENOENT"""
.el .Sh "\f(CWis_ENOENT\fP"
.IX Subsection "is_ENOENT"
Check if the error is matching \f(CW\*(C`ENOENT\*(C'\fR and its variants (corresponds
to the \f(CW\*(C`APR_STATUS_IS_ENOENT\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_ENOENT($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
An example of using \f(CW\*(C`is_ENOENT\*(C'\fR is when reading the contents of a
file which may not exist:
.PP
.Vb 6
\&  eval { $obj\->slurp_filename(0) };
\&  if ($@) {
\&      return Apache2::Const::NOT_FOUND
\&          if ref $@ eq \*(AqAPR::Error\*(Aq && APR::Status::is_ENOENT($@);
\&      die $@;
\&  }
.Ve
.PP
Due to possible variants in conditions matching \f(CW\*(C`ENOENT\*(C'\fR,
the use of this function is recommended for checking error codes
against this value, rather than just using
\&\f(CW\*(C`APR::Const::ENOENT\*(C'\fR
directly.
.ie n .Sh """is_EOF"""
.el .Sh "\f(CWis_EOF\fP"
.IX Subsection "is_EOF"
Check if the error is matching \f(CW\*(C`EOF\*(C'\fR and its variants (corresponds
to the \f(CW\*(C`APR_STATUS_IS_EOF\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_EOF($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
Due to possible variants in conditions matching \f(CW\*(C`EOF\*(C'\fR,
the use of this function is recommended for checking error codes
against this value, rather than just using
\&\f(CW\*(C`APR::Const::EOF\*(C'\fR
directly.
.ie n .Sh """is_ECONNABORTED"""
.el .Sh "\f(CWis_ECONNABORTED\fP"
.IX Subsection "is_ECONNABORTED"
Check if the error is matching \f(CW\*(C`ECONNABORTED\*(C'\fR and its variants (corresponds
to the \f(CW\*(C`APR_STATUS_IS_ECONNABORTED\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_ECONNABORTED($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
Due to possible variants in conditions matching \f(CW\*(C`ECONNABORTED\*(C'\fR,
the use of this function is recommended for checking error codes
against this value, rather than just using
\&\f(CW\*(C`APR::Const::ECONNABORTED\*(C'\fR directly.
.ie n .Sh """is_ECONNRESET"""
.el .Sh "\f(CWis_ECONNRESET\fP"
.IX Subsection "is_ECONNRESET"
Check if the error is matching \f(CW\*(C`ECONNRESET\*(C'\fR and its variants
(corresponds to the \f(CW\*(C`APR_STATUS_IS_ECONNRESET\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_ECONNRESET($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
Due to possible variants in conditions matching \f(CW\*(C`ECONNRESET\*(C'\fR, the use
of this function is recommended for checking error codes against this
value, rather than just using
\&\f(CW\*(C`APR::Const::ECONNRESET\*(C'\fR
directly.
.ie n .Sh """is_TIMEUP"""
.el .Sh "\f(CWis_TIMEUP\fP"
.IX Subsection "is_TIMEUP"
Check if the error is matching \f(CW\*(C`TIMEUP\*(C'\fR and its variants (corresponds
to the \f(CW\*(C`APR_STATUS_IS_TIMEUP\*(C'\fR macro).
.PP
.Vb 1
\&  $status = APR::Status::is_TIMEUP($error_code);
.Ve
.ie n .IP "arg1: $error_code\fR (integer or \f(CW""APR::Error object"" )" 4
.el .IP "arg1: \f(CW$error_code\fR (integer or \f(CWAPR::Error object\fR )" 4
.IX Item "arg1: $error_code (integer or APR::Error object )"
The error code or to check, normally \f(CW$@\fR blessed into \f(CW\*(C`APR::Error
object\*(C'\fR.
.ie n .IP "ret: $status ( boolean )" 4
.el .IP "ret: \f(CW$status\fR ( boolean )" 4
.IX Item "ret: $status ( boolean )"
.PD 0
.IP "since: 2.0.00" 4
.IX Item "since: 2.0.00"
.PD
.PP
Due to possible variants in conditions matching \f(CW\*(C`TIMEUP\*(C'\fR,
the use of this function is recommended for checking error codes
against this value, rather than just using
\&\f(CW\*(C`APR::Const::TIMEUP\*(C'\fR
directly.
.SH "See Also"
.IX Header "See Also"
mod_perl 2.0 documentation.
.SH "Copyright"
.IX Header "Copyright"
mod_perl 2.0 and its core modules are copyrighted under
The Apache Software License, Version 2.0.
.SH "Authors"
.IX Header "Authors"
The mod_perl development team and numerous
contributors.