nanohttp: minimal HTTP implementation

## nanohttp

nanohttp - minimal HTTP implementation

minimal HTTP implementation allowing to fetch resources like external subset.

Author(s): Daniel Veillard

## Synopsis

    int	xmlNanoHTTPRead			(void * ctx,
    					 void * dest,
    					 int len);
    int	xmlNanoHTTPSave			(void * ctxt,
    					 const char * filename);
    const char *	xmlNanoHTTPRedir	(void * ctx);
    const char *	xmlNanoHTTPAuthHeader	(void * ctx);
    int	xmlNanoHTTPFetch		(const char * URL,
    					 const char * filename,
    					 char ** contentType);
    int	xmlNanoHTTPContentLength	(void * ctx);
    const char *	xmlNanoHTTPMimeType	(void * ctx);
    void	xmlNanoHTTPClose		(void * ctx);
    void	xmlNanoHTTPCleanup		(void);
    void *	xmlNanoHTTPMethod		(const char * URL,
    					 const char * method,
    					 const char * input,
    					 char ** contentType,
    					 const char * headers,
    					 int ilen);
    void	xmlNanoHTTPInit			(void);
    void *	xmlNanoHTTPOpen			(const char * URL,
    					 char ** contentType);
    void *	xmlNanoHTTPOpenRedir		(const char * URL,
    					 char ** contentType,
    					 char ** redir);
    void *	xmlNanoHTTPMethodRedir		(const char * URL,
    					 const char * method,
    					 const char * input,
    					 char ** contentType,
    					 char ** redir,
    					 const char * headers,
    					 int ilen);
    void	xmlNanoHTTPScanProxy		(const char * URL);
    const char *	xmlNanoHTTPEncoding	(void * ctx);
    int	xmlNanoHTTPReturnCode		(void * ctx);

## Description

## Details

### xmlNanoHTTPAuthHeader ()

    const char *	xmlNanoHTTPAuthHeader	(void * ctx)

Get the authentication header of an HTTP context

`ctx`: | the HTTP context
`Returns`: | the stashed value of the WWW-Authenticate or Proxy-Authenticate header.

### xmlNanoHTTPCleanup ()

    void	xmlNanoHTTPCleanup		(void)

Cleanup the HTTP protocol layer.

### xmlNanoHTTPClose ()

    void	xmlNanoHTTPClose		(void * ctx)

This function closes an HTTP context, it ends up the connection and free all data related to it.

`ctx`: | the HTTP context

### xmlNanoHTTPContentLength ()

    int	xmlNanoHTTPContentLength	(void * ctx)

Provides the specified content length from the HTTP header.

`ctx`: | the HTTP context
`Returns`: | the specified content length from the HTTP header. Note that a value of -1 indicates that the content length element was not included in the response header.

### xmlNanoHTTPEncoding ()

    const char *	xmlNanoHTTPEncoding	(void * ctx)

Provides the specified encoding if specified in the HTTP headers.

`ctx`: | the HTTP context
`Returns`: | the specified encoding or NULL if not available

### xmlNanoHTTPFetch ()

    int	xmlNanoHTTPFetch		(const char * URL,
    					 const char * filename,
    					 char ** contentType)

This function try to fetch the indicated resource via HTTP GET and save it's content in the file.

`URL`: | The URL to load
`filename`: | the filename where the content should be saved
`contentType`: | if available the Content-Type information will be returned at that location
`Returns`: | -1 in case of failure, 0 in case of success. The contentType, if provided must be freed by the caller

### xmlNanoHTTPInit ()

    void	xmlNanoHTTPInit			(void)

Initialize the HTTP protocol layer. Currently it just checks for proxy information

### xmlNanoHTTPMethod ()

    void *	xmlNanoHTTPMethod		(const char * URL,
    					 const char * method,
    					 const char * input,
    					 char ** contentType,
    					 const char * headers,
    					 int ilen)

This function try to open a connection to the indicated resource via HTTP using the given @method, adding the given extra headers and the input buffer for the request content.

`URL`: | The URL to load
`method`: | the HTTP method to use
`input`: | the input string if any
`contentType`: | the Content-Type information IN and OUT
`headers`: | the extra headers
`ilen`: | input length
`Returns`: | NULL in case of failure, otherwise a request handler. The contentType, if provided must be freed by the caller

### xmlNanoHTTPMethodRedir ()

    void *	xmlNanoHTTPMethodRedir		(const char * URL,
    					 const char * method,
    					 const char * input,
    					 char ** contentType,
    					 char ** redir,
    					 const char * headers,
    					 int ilen)

This function try to open a connection to the indicated resource via HTTP using the given @method, adding the given extra headers and the input buffer for the request content.

`URL`: | The URL to load
`method`: | the HTTP method to use
`input`: | the input string if any
`contentType`: | the Content-Type information IN and OUT
`redir`: | the redirected URL OUT
`headers`: | the extra headers
`ilen`: | input length
`Returns`: | NULL in case of failure, otherwise a request handler. The contentType, or redir, if provided must be freed by the caller

### xmlNanoHTTPMimeType ()

    const char *	xmlNanoHTTPMimeType	(void * ctx)

Provides the specified Mime-Type if specified in the HTTP headers.

`ctx`: | the HTTP context
`Returns`: | the specified Mime-Type or NULL if not available

### xmlNanoHTTPOpen ()

    void *	xmlNanoHTTPOpen			(const char * URL,
    					 char ** contentType)

This function try to open a connection to the indicated resource via HTTP GET.

`URL`: | The URL to load
`contentType`: | if available the Content-Type information will be returned at that location
`Returns`: | NULL in case of failure, otherwise a request handler. The contentType, if provided must be freed by the caller

### xmlNanoHTTPOpenRedir ()

    void *	xmlNanoHTTPOpenRedir		(const char * URL,
    					 char ** contentType,
    					 char ** redir)

This function try to open a connection to the indicated resource via HTTP GET.

`URL`: | The URL to load
`contentType`: | if available the Content-Type information will be returned at that location
`redir`: | if available the redirected URL will be returned
`Returns`: | NULL in case of failure, otherwise a request handler. The contentType, if provided must be freed by the caller

### xmlNanoHTTPRead ()

    int	xmlNanoHTTPRead			(void * ctx,
    					 void * dest,
    					 int len)

This function tries to read @len bytes from the existing HTTP connection and saves them in @dest. This is a blocking call.

`ctx`: | the HTTP context
`dest`: | a buffer
`len`: | the buffer length
`Returns`: | the number of byte read. 0 is an indication of an end of connection. -1 indicates a parameter error.

### xmlNanoHTTPRedir ()

    const char *	xmlNanoHTTPRedir	(void * ctx)

Provides the specified redirection URL if available from the HTTP header.

`ctx`: | the HTTP context
`Returns`: | the specified redirection URL or NULL if not redirected.

### xmlNanoHTTPReturnCode ()

    int	xmlNanoHTTPReturnCode		(void * ctx)

Get the latest HTTP return code received

`ctx`: | the HTTP context
`Returns`: | the HTTP return code for the request.

### xmlNanoHTTPSave ()

    int	xmlNanoHTTPSave			(void * ctxt,
    					 const char * filename)

This function saves the output of the HTTP transaction to a file It closes and free the context at the end

`ctxt`: | the HTTP context
`filename`: | the filename where the content should be saved
`Returns`: | -1 in case of failure, 0 in case of success.

### xmlNanoHTTPScanProxy ()

    void	xmlNanoHTTPScanProxy		(const char * URL)

(Re)Initialize the HTTP Proxy context by parsing the URL and finding the protocol host port it indicates. Should be like http://myproxy/ or http://myproxy:3128/ A NULL URL cleans up proxy information.

`URL`: | The proxy URL used to initialize the proxy context