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libpowerman(3) Library Functions Manual libpowerman(3)

NAME

libpowerman - PowerMan Client API

SYNOPSIS

#include <libpowerman.h>

pm_err_t pm_connect (char *server, void *arg, pm_handle_t *hp,
                     int flags);

void pm_disconnect (pm_handle_t h);

pm_err_t pm_node_on (pm_handle_t h, char *node);

pm_err_t pm_node_off (pm_handle_t h, char *node);

pm_err_t pm_node_cycle (pm_handle_t h, char *node);

pm_err_t pm_node_status (pm_handle_t h, char *node,
                         pm_node_state_t sp);

pm_err_t pm_node_iterator_create (pm_handle_t h,
                                  pm_node_iterator_t *ip);

void pm_node_iterator_destroy (pm_node_iterator_t i);

char * pm_node_next (pm_node_iterator_t i);

void pm_node_iterator_reset (pm_node_iterator_t i);

char * pm_strerror (pm_err_t err, char * str, int len);

cc ... -lpowerman

DESCRIPTION

The pm_connect() function establishes a connection with server, a string containing host[:port] or NULL for defaults; and returns a handle in hp. The arg parameter is currently unused. The flags parameter should be zero or one or more logically-OR'ed flags:

Establish connection to the powerman server using (only) IPv6 protocol. Without this flag, any available address family will be used.

The pm_disconnect() function tears down the server connection and frees storage associated with handle h.

The pm_node_on(), pm_node_off(), and pm_node_cycle() functions issue on, off, and cycle commands acting on node to the server on handle h.

The pm_node_status() function issues a status query acting on node to the server on handle h. The result is resturned in sp which will be one of the values:

Node is powered on.
Node is powered off.
Node state is unknown. Some devices may return this even when the query is successful, for example X10 devices controlled by plmpower.

To use the above functions you must know the name of the node you wish to control. Calling pm_node_iterator_create() on handle h returns an iterator ip which can be used to walk the list of valid node names. pm_node_next() returns the next node in the list, or NULL when the end of the list is reached. pm_node_iterator_reset() rewinds iterator i to the beginning of the list. Finally, pm_node_iterator_destroy() destroys an iterator and reclaims its storage.

RETURN VALUE

Most functions have a return type of pm_err_t. pm_strerror() is available to convert an error code err to a human-readable string using storage str of length len passed in by the caller.

ERRORS

Success.
System call failed, see system errno.
Failed to get address info for server.
Connect failed.
Out of memory.
Bad server handle.
Bad argument.
Received unexpected EOF from server.
Received unexpected response from server.
Server responded with ``unknown command''.
Server responded with ``parse error''.
Server responded with ``command too long''.
Server responded with ``internal error''.
Server responded with ``hostlist error''.
Server responded with ``command in progress''.
Server responded with ``no such nodes''.
Server responded with ``command completed with errors''.
Server responded with ``query completed with errors''.
Server responded with ``not implemented by device''.

EXAMPLE

This example program queries the list of valid nodes and turns them all on.

#include <stdio.h>
#include <stdlib.h>
#include <libpowerman.h>

int
main(int argc, char *argv[])
{


    pm_err_t err;


    pm_node_state_t s;


    pm_handle_t h;


    pm_node_iterator_t i;


    char ebuf[64], *node;



    if ((err = pm_connect (NULL, NULL, &h, 0)) != PM_ESUCCESS) {


        fprintf (stderr, "pm_connect: %s\n",


                pm_strerror (err, ebuf, sizeof (ebuf)));


        exit(1);


    }



    if ((err = pm_node_iterator_create (h, &i)) != PM_ESUCCESS) {


        fprintf (stderr, "pm_node_iterator_create: %s\n",


                pm_strerror (err, ebuf, sizeof (ebuf)));


        exit(1);


    }


    while ((node = pm_node_next (i))) {


        if ((err = pm_node_on (h, node)) != PM_ESUCCESS) {


            fprintf (stderr, "pm_node_on: %s\n",


                    pm_strerror (err, ebuf, sizeof(ebuf)));


            exit (1);


        }


    }


    pm_node_iterator_destroy (i);



    pm_disconnect (h);


    exit (0);
}

FILES

/usr/lib/x86_64-linux-gnu/libpowerman.*
/usr/include/libpowerman.h

ORIGIN

PowerMan was originally developed by Andrew Uselton on LLNL's Linux clusters. This software is open source and distributed under the terms of the GNU GPL.

SEE ALSO

powerman(1), powermand(8), httppower(8), plmpower(8), vpcd(8), powerman.conf(5), powerman.dev(5).

http://github.com/chaos/powerman

2 December 2008 powerman-2.4.4