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cfg_subsys_defaults(3)
Contents
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cfg_subsys_defaults - determine the /etc/sysconfigtab
value for selected attributes of a subsystem
#include <cfg.h>
cfg_status_t cfg_subsys_defaults(
cfg_handle_t *handle,
caddr_t subsys,
cfg_attr_t *attributes,
int nattributes );
Configuration Management Library (libcfg.a)
Structure identifying the means of communication between
your application and the configuration manager server. For
local requests, pass NULL in this parameter. For remote
requests, pass the value returned from the cfg_connect()
routine. Specifies the name of the subsystem for which
you are requesting default attribute values. On input,
names the attributes for which you are requesting a
default value.
On return, contains information about the named
attributes. The information includes the attributespecific
status of the cfg_subsys_defaults()
request and the default value of the attribute as
specified in the /etc/sysconfigtab database. Specifies
the number of attributes in the input
attribute list.
Use the cfg_subsys_defaults() routine to get information
about the value assigned to attributes in the /etc/sysconfigtab
database. You can request information about one or
more attributes, but you can get information about only
one subsystem at a time. (For information about the
/etc/sysconfigtab database, see sysconfigtab(4).)
In the call to the cfg_subsys_defaults() routine, your
application passes the subsystem name and a list of one or
more attribute names. The system reads this information
and finds and collects the information about the named
attributes. The system then returns the attribute information
to your application.
The information returned from the cfg_subsys_defaults()
routine is passed in a structure of type cfg_attr_t. If
your application requests information about more than one
attribute, an array of structures is returned. For information
about this structure, see libcfg(3).
The following list describes the information returned to
your application when it calls the cfg_subsys_defaults()
routine: Attributes can be integer, string, or binary
data. However, the system is unable to determine the data
type of attributes by reading the /etc/sysconfigtab
database. Therefore, this field returns the CFG_ATTR_STRTYPE
data type for all attributes. The definition of each
attribute in the subsystem attribute table determines what
operations you can perform on the attribute. The system is
unable to determine this information from the /etc/sysconfigtab
database, so this field is NULL on return from
cfg_subsys_defaults() requests. During a cfg_subsys_defaults()
request, the system assigns each attribute
a status. The following table describes the status values
your application might receive on return from this routine:
---------------------------------------------------------------------
Status Code Meaning
---------------------------------------------------------------------
CFG_ATTR_SUCCESS Successful operation
CFG_ATTR_EEXISTS No attribute by that name exists
CFG_ATTR_EOP Attribute does not support the query operation
CFG_ATTR_ESUBSYS Subsystem failure (code within the subsystem
returned an error)
CFG_ATTR_EINDEX The index for an indexed attribute is out of
range
CFG_ATTR_EMEM Unable to allocate memory to return the attribute
value
---------------------------------------------------------------------
The value of each attribute is returned in a structure,
which contains a string representing the
value of the attribute as it is defined in the
/etc/sysconfigtab database. If an attribute is
omitted from the database, the cfg_subsys_defaults()
routine returns a NULL attribute
value.
The cfg_subsys_defaults() routine returns NULL for
other fields in the attribute value structure.
Upon successful completion, cfg_subsys_defaults() returns
CFG_SUCCESS. Other return values indicate that an error
has occurred. For information about handling return values
from routines in the configuration management library, see
libcfg(3).
The following example illustrates the use of the cfg_subsys_defaults()
routine:
cfg_attr_t attributes[2]; cfg_status_t
retval; cfg_handle_t handle; int
i;
/*****************************************************/ /*
Initialize attribute names for the request */
strcpy (attributes[0].name, "bufcache"); strcpy
(attributes[1].name, "max-vnodes");
/***************************************************/ /*
Call the cfg_subsys_defaults routine */
retval = cfg_subsys_defaults(&handle, "vfs", attributes,
2);
if (retval != CFG_SUCCESS)
print_error (retval);
else {
/* Use data returned from the request */
for (i=0; i<2; i++) {
printf ("%s", attributes[i].name);
if (attributes[i].status != CFG_ATTR_SUCCESS) {
switch (attributes[i].status){
case CFG_ATTR_EEXISTS:
printf("unknown attribute\n");
break;
case CFG_ATTR_EOP:
printf("attribute does not allow this operation\n");
break;
.
.
.
default:
printf("unknown error\n");
break;
}
continue;
}
/* Display attribute value to application user */
printf ("%s\n", attributes[i].attr.str.val);
}
free(attributes[i].attr.str.val);
break; }
In this example, the application requests information
about two attributes, bufcache and max-vnodes. When the
cfg_subsys_defaults() routine returns information about
those attributes, the application tests the return status
of the routine and reports any errors returned. If the
cfg_subsys_defaults() routine returns CFG_SUCCESS, the
status for each attribute is tested and any errors are
reported. The application displays the default value of
attributes that return CFG_ATTR_SUCCESS.
Commands: cfgmgr(8), sysconfig(8)
Routines: cfg_connect(3), cfg_subsys_defaults_all(3),
libcfg(3)
Files: sysconfigtab(4)
cfg_subsys_defaults(3)
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