-The API is simple, and designed to be a minimal wrapper around the serial port
-support in each OS.
-
-Most functions take a pointer to a struct sp_port, which represents a serial
-port. These structures are always allocated and freed by the library, using the
-functions in the 'Enumeration' section below.
-
-All functions can return only three possible error values. SP_ERR_ARG indicates
-the function was called with invalid arguments. SP_ERR_FAIL indicates that the
-OS reported a failure. SP_ERR_MEM indicates that a memory allocation failed.
-All of these error values are negative.
-
-When SP_ERR_FAIL is returned, an error code or string description of the error
-can be obtained by calling sp_last_error_code() or sp_last_error_message(). The
-error code or message is that provided by the OS; libserialport does not define
-any error codes or messages of its own.
-
-Function calls that succeed return SP_OK, which is equal to zero, or where
-otherwise documented a positive value.
-
-The available functions are as follows:
-
-Enumeration
------------
-
-int sp_get_port_by_name(const char *portname, struct sp_port **port_ptr);
-
- Obtains a pointer to a new sp_port structure representing the named port. The
- user should allocate a variable of type "struct sp_port *" and pass a pointer
- to this to receive the result.
-
- The result should be freed after use by calling sp_free_port().
-
- Returns: SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation
- failure, or SP_ERR_ARG if an invalid pointer is passed. If any error
- is returned, the variable pointed to by port_ptr will be set to NULL.
- Otherwise, it will be set to point to the newly allocated port.
-
-void sp_free_port(struct sp_port *port);
-
- Frees a port structure obtained from sp_get_port_by_name().
-
-int sp_list_ports(struct sp_port ***list_ptr);
-
- Lists the serial ports available on the system. The result obtained is an
- array of pointers to sp_port structures, terminated by a NULL. The user should
- allocate a variable of type "struct sp_port **" and pass a pointer to this to
- receive the result.
-
- The result should be freed after use by calling sp_free_port_list(). If a port
- from the list is to be used after freeing the list, it must be copied first
- using sp_copy_port().
-
- Returns: SP_OK on success, SP_ERR_FAIL on failure, SP_ERR_MEM on allocation
- failure, or SP_ERR_ARG if an invalid pointer is passed. If any error
- is returned, the variable pointed to by list_ptr will be set to NULL.
- Otherwise, it will be set to point to the newly allocated array.
-
-int sp_copy_port(const struct sp_port *port, struct sp_port **copy_ptr);
-
- Makes a new copy of a sp_port structure. The user should allocate a variable
- of type "struct sp_port *" and pass a pointer to this to receive the result.
-
- The copy should be freed after use by calling sp_free_port().
-
- Returns: SP_OK on success, SP_ERR_MEM on allocation failure, or SP_ERR_ARG
- if an invalid port or pointer is passed. If any error is returned,
- the variable pointed to by copy_ptr will be set to NULL. Otherwise,
- it will be set to point to the newly allocated copy.
-
-void sp_free_port_list(struct sp_port **list);
-
- Frees a port list obtained from sp_list_ports(). This will also free all
- the sp_port structures referred to from the list; any that are to be retained
- must be copied first using sp_copy_port().
-
-Opening and closing ports
--------------------------
-
-int sp_open(struct sp_port *port, int flags);