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gensio_add_default(3)	    Library Functions Manual	   gensio_add_default(3)

NAME
     gensio_add_default,  gensio_set_default, gensio_get_default, gensio_get_de-
     faultaddr, gensio_del_default, gensio_reset_defaults - Handle default  val-
     ues for gensios

SYNOPSIS
     #include <gensio/gensio.h>
     struct gensio_enum_val {
	 char *name;
	 int val;
     };

     int gensio_add_default(struct gensio_os_funcs *o,
			 const char *name,
			 enum gensio_default_type type,
			 const char *strval, int intval,
			 int minval, int maxval,
			 const struct gensio_enum_val *enums);

     int gensio_set_default(struct gensio_os_funcs *o,
			 const char *class, const char *name,
			 const char *strval, int intval);

     int gensio_get_default(struct gensio_os_funcs *o,
			 const char *class, const char *name,
			 bool classonly,
			 enum gensio_default_type type,
			 char **strval, int *intval);

     int gensio_get_defaultaddr(struct gensio_os_funcs *o,
			 const char *class, const char *name,
			 bool classonly,
			 int iprotocol, bool listen,
			 bool require_port,
			 struct addrinfo **rai);

     int gensio_del_default(struct gensio_os_funcs *o,
			 const char *class, const char *name,
			 bool delclasses);

     int gensio_reset_defaults(struct gensio_os_funcs *o);

DESCRIPTION
     Defaults  provide	a  way to set overall or class-based defaults for gensio
     options (or you can use it yourself to create your own defaults).	The var-
     ious options for gensios are described in gensio(5).

     For default values, each class will use gensio_get_default with their class
     (serialdev, telnet, ssl, etc.) with the name as the given option name.   If
     a value has been set for its class, it will use that value.  If a value has
     been set with class set to NULL (a "global" default) then the value will be
     used  from  there.   Otherwise  the code will use it's own internal default
     value.

     Any option provided in the gensio string will override any  default  value,
     of course.

     The  classonly  parameter means to not look in the global defaults.  If you
     use this for your own defaults, it is recommended that  you  use  your  own
     class and set classonly to true.

     Defaults  come  in one of four formats defined by type: GENSIO_DEFAULT_INT,
     GENSIO_DEFAULT_BOOL,  GENSIO_DEFAULT_ENUM,  GENSIO_DEFAULT_STR,  GENSIO_DE-
     FAULT_DATA.   int and bool are pretty self-explanatory.  Except that if you
     pass in a non-NULL strval when setting one, the code will	attempt  to  get
     the  value  from the strval and will return NULL if the value is not valid.
     It will attempt to translate "true" and "false" for bool  values.	 If  the
     value  is <minval or >maxval, GE_OUTOFRANGE is returned from any set opera-
     tion.

     When setting a str, the value is copied, you don't have to  keep  the  copy
     around for yourself.

     When  getting  a  string value, the value is duplicated with gensio_strdup,
     you should free it with o->free().

     Data is like strings, except the length is passed in intval and it  is  re-
     turned  the  same	way.   This will hold arbitrary raw data.  Like strings,
     when you get a data value you should free it with o->free().

     If it's a enum, setting the value you will pass in a string and a table  of
     possible  values in enum (terminated with a NULL name).  The code will look
     up the string you pass in in the enums table, and set the value to the  in-
     teger  value.   If  the  string  is  not in the enums table, it will return
     GE_INVAL.	When you get the value, it will return the value in intval.

     When getting the value, the type must match what is set in  the  set  call.
     If  the  name  is not found, GE_NOTFOUND is returned.  If the type does not
     match, then GE_INVAL is returned.	Note that if you  save	a  value  as  an
     enum, you can fetch it as an int.

     Setting the same default again will replace the old value.

     gensio_del_default  deletes  the  given default.  You can only delete user-
     added defaults, not ones created by the gensio library.  If there	are  any
     class-specific  default registered against the default, this call will fail
     with GE_INUSE unless delclasses is true, which will cause all the class de-
     faults to be deleted, too.

     gensio_reset_defaults will reset all defaults to the value  set  when  gen-
     sio_add_default  was  called to create the default, or the built-in default
     value.

     gesnio_get_defaultaddr gets an address from the given default string.   See
     gensi_scan_network_port in gensio/gensio.h for details on how the string is
     formatted, what the parameters mean, and how to handle the addrinfo struct.

RETURN VALUES
     Zero is returned on success, or a gensio error on failure.

SEE ALSO
     gensio_err(3), gensio(5)

				   27 Feb 2019		   gensio_add_default(3)
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