OWNET(1) One-Wire File System OWNET(1)NAME
ownet , (libownet) - easy C-language 1-wire interface to the owserver
protocol
SYNOPSIS
libownet library to link with your program
Handle
OWNET_HANDLE
Handle to each owserver connection
Initialization
OWNET_HANDLE OWNET_init( const char * owserver_tcp_address_and_port )
Associate an owserver (1) tcp/ip address with a handle.
Directory listing
int OWNET_dirlist( OWNET_HANDLE owserver_handle , const char *
onewire_path , char ** comma_separated_list )
Create a comma-separated list of directory elements.
int OWNET_dirprocess( OWNET_HANDLE owserver_handle , const char *
onewire_path , void (* dirfunc ) (void *, const char *), void *
passed_on_value )
void dirfunc ( void * passed_on_value , const char * directory_element
)
Apply function dirfunc to each directory element, along with an arbi‐
trary passed_on_value.
Get data
int OWNET_read( OWNET_HANDLE owserver_handle , const char *
onewire_path , const char ** return_string )
Read a value (of specified size) from a 1-wire device.
int OWNET_lread( OWNET_HANDLE owserver_handle , const char *
onewire_path , const char ** return_string , size_t size , off_t offset
)
Read a value (of specified size and offset) from a 1-wire device.
int OWNET_present( OWNET_HANDLE owserver_handle , const char *
onewire_path )
Check if a 1-wire device is present.
Set data
int OWNET_put( OWNET_HANDLE owserver_handle , const char * onewire_path
, const char * value_string , size_t size )
Write a value (of specified size) to a 1-wire device.
int OWNET_lwrite( OWNET_HANDLE owserver_handle , const char *
onewire_path , const char * value_string , size_t size , off_t offset )
Write a value (of specified size and offset) to a 1-wire device.
Close
void OWNET_close( OWNET_HANDLE owserver_handle )
Close the connection to a particular owserver.
void OWNET_closeall( void )
Close all open owserver connections.
void OWNET_finish( void )
Close all open owserver connections and free all memory.
Temperature scale
void OWNET_set_temperature_scale( char temperature_scale )
char OWNET_get_temperature_scale( void )
Set and retrieve the temperature scale used for all communications.
Device format
void OWNET_set_device_format( const char * device_format )
const char * OWNET_get_device_format( void )
Set and retrieve the 1-wire device serial number format used for all
communications.
FUNCTIONS
OW_init
OW_init_string offers the full flexibility of the owfs (1) and owhttpd
(1) command line.
Arguments
Can be as simple as jus the device name, a full parameter speci‐
fication. One or more device names (includes tcp, serial,
usb...) and command line switches. See owfs (1) for full syntax.
Returns
0 for success. -1 on error and errno will be set. OW_finish
does not need to be called if OW_init fails.
Sequence
One of the init functions must be called before accessing the
1-wire bus. OW_finish is optional.
OW_init_args
OW_init_args offers the full flexibility of the owfs (1) and owhttpd
(1) command line.
Arguments
One or more device names (includes tcp, serial, usb...) and com‐
mand line switches. See owfs (1) for full syntax. Unlike
OW_init_string the arguments are in argv/argc format.
Returns
0 for success. -1 on error and errno will be set. OW_finish
does not need to be called if OW_init fails.
Sequence
One of the init functions must be called before accessing the
1-wire bus. OW_finish is optional.
OW_get
OW_get is used to get directory listings and file contents. The results
are put in a dynamically allocated buffer.
Arguments
path is the path to the directory or file (property). *buffer
returns a pointer to a buffer containing the directory (comma
separated) or value. buffer_length returns the length of the
value/string in buffer
Returns
number of bytes on success. -1 on error (and errno is set).
Sequence
One of the init functions must be called before accessing the
1-wire bus. OW_finish is optional.
Important note
buffer is allocated ( with malloc ) by OW_get but must be freed
in your program. See malloc (3) and free (3)
OW_lread
OW_lread is used to read 1-wire memory chips. Think of it as a combina‐
tion of lseek and read It allows random-access to the memory, specify‐
ing location and length. Unlike OW_get directories cannot be obtained
and the buffer must be pre-allocated rather than allocated by the rou‐
tine. buffer must be at least size length.
Arguments
path is the path to the file (property). buffer is the (pre-
allocated) memory area where the value will be placed. size is
the length of bytes requested. offset is the position in file
to start reading.
Returns
number of bytes on success. -1 on error (and errno is set).
Sequence
One of the init functions must be called before accessing the
1-wire bus. OW_finish is optional.
OW_put
OW_put is an easy way to write to 1-wire chips.
Arguments
path is the path to the file (property). buffer is the value to
be written. buffer_length is the length of the value buffer.
Returns number of bytes on success. -1 on error (and errno is
set).
Sequence
One of the init functions must be called before accessing the
1-wire bus. OW_finish is optional.
OW_lwrite
OW_lwrite is the companion of OW_lread. It allows writing to arbitrary
positions in 1-wire memory. Think of it as a combination of lseek and
write. buffer must be at least size length.
Arguments
path is the path to the file (property). buffer is the data to
be written. size is the length of bytes to be written. offset
is the position in file to start writing.
Returns
number of bytes on success. -1 on error (and errno is set).
Sequence
One of the init functions must be called before accessing the
1-wire bus. OW_finish is optional.
OW_finish
OW_finish cleans up the OWFS 1-wire routines, releases devices and mem‐
ory.
Arguments
None.
Returns
None
Sequence
OW_finish is optional since cleanup is automatic on program
exit.
DESCRIPTION
libowcapi
libowcapi (1) is an encapsulation of the full libow library for C pro‐
grams.
libowcapi (1) allows a C program to use OWFS principles (consistent
naming scheme, multiple adapters, devices, and compatibility) directly
from a C program. There are analogous modules for other programming
languages:
C libowcapi
perl owperl
php owphp
python owpython
tcl owtcl
EXAMPLE
/* Simple directory listing -- no error checking */
#include <ownetapi.h>
char * buf;
size_t s ;
OWNET_init("localhost:4304");
OWNET_dirlist("/",&buf,&s) ;
printf("Directory %s0,buf);
free(buf);
OWNET_finish() ;
SEE ALSOAVAILABILITY
http://www.owfs.org
AUTHOR
Paul Alfille (paul.alfille@gmail.com)
OWFS Manpage 2008 OWNET(1)
