lwp::mediatypes.3

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

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.\" ========================================================================
.\"
.IX Title "LWP::MediaTypes 3"
.TH LWP::MediaTypes 3 "2007-07-19" "perl v5.10.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
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.nh
.SH "NAME"
LWP::MediaTypes \- guess media type for a file or a URL
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 2
\& use LWP::MediaTypes qw(guess_media_type);
\& $type = guess_media_type("/tmp/foo.gif");
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This module provides functions for handling media (also known as
\&\s-1MIME\s0) types and encodings.  The mapping from file extensions to media
types is defined by the \fImedia.types\fR file.  If the \fI~/.media.types\fR
file exists it is used instead.
For backwards compatibility we will also look for \fI~/.mime.types\fR.
.PP
The following functions are exported by default:
.ie n .IP "guess_media_type( $filename )" 4
.el .IP "guess_media_type( \f(CW$filename\fR )" 4
.IX Item "guess_media_type( $filename )"
.PD 0
.ie n .IP "guess_media_type( $uri )" 4
.el .IP "guess_media_type( \f(CW$uri\fR )" 4
.IX Item "guess_media_type( $uri )"
.ie n .IP "guess_media_type( $filename_or_uri\fR, \f(CW$header_to_modify )" 4
.el .IP "guess_media_type( \f(CW$filename_or_uri\fR, \f(CW$header_to_modify\fR )" 4
.IX Item "guess_media_type( $filename_or_uri, $header_to_modify )"
.PD
This function tries to guess media type and encoding for a file or a \s-1URI\s0.
It returns the content type, which is a string like \f(CW"text/html"\fR.
In array context it also returns any content encodings applied (in the
order used to encode the file).  You can pass a \s-1URI\s0 object
reference, instead of the file name.
.Sp
If the type can not be deduced from looking at the file name,
then \fIguess_media_type()\fR will let the \f(CW\*(C`\-T\*(C'\fR Perl operator take a look.
If this works (and \f(CW\*(C`\-T\*(C'\fR returns a \s-1TRUE\s0 value) then we return
\&\fItext/plain\fR as the type, otherwise we return
\&\fIapplication/octet\-stream\fR as the type.
.Sp
The optional second argument should be a reference to a HTTP::Headers
object or any object that implements the \f(CW$obj\fR\->header method in a
similar way.  When it is present the values of the
\&'Content\-Type' and 'Content\-Encoding' will be set for this header.
.ie n .IP "media_suffix( $type, ... )" 4
.el .IP "media_suffix( \f(CW$type\fR, ... )" 4
.IX Item "media_suffix( $type, ... )"
This function will return all suffixes that can be used to denote the
specified media type(s).  Wildcard types can be used.  In a scalar
context it will return the first suffix found. Examples:
.Sp
.Vb 2
\&  @suffixes = media_suffix(\*(Aqimage/*\*(Aq, \*(Aqaudio/basic\*(Aq);
\&  $suffix = media_suffix(\*(Aqtext/html\*(Aq);
.Ve
.PP
The following functions are only exported by explicit request:
.ie n .IP "add_type( $type\fR, \f(CW@exts )" 4
.el .IP "add_type( \f(CW$type\fR, \f(CW@exts\fR )" 4
.IX Item "add_type( $type, @exts )"
Associate a list of file extensions with the given media type.
Example:
.Sp
.Vb 1
\&    add_type("x\-world/x\-vrml" => qw(wrl vrml));
.Ve
.ie n .IP "add_encoding( $type\fR, \f(CW@ext )" 4
.el .IP "add_encoding( \f(CW$type\fR, \f(CW@ext\fR )" 4
.IX Item "add_encoding( $type, @ext )"
Associate a list of file extensions with an encoding type.
Example:
.Sp
.Vb 1
\& add_encoding("x\-gzip" => "gz");
.Ve
.ie n .IP "read_media_types( @files )" 4
.el .IP "read_media_types( \f(CW@files\fR )" 4
.IX Item "read_media_types( @files )"
Parse media types files and add the type mappings found there.
Example:
.Sp
.Vb 1
\&    read_media_types("conf/mime.types");
.Ve
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright 1995\-1999 Gisle Aas.
.PP
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.