cfg_subsys_defaults(3) Library Functions Manual cfg_subsys_defaults(3)
NAME
cfg_subsys_defaults - Determine the /etc/sysconfigtab value for selected attributes of a subsystem
LIBRARY
Configuration Management Library (libcfg.a)
SYNOPSIS
#include <cfg.h> cfg_status_t cfg_subsys_defaults(
cfg_handle_t *handle,
caddr_t subsys,
cfg_attr_t *attributes,
int nattributes);
PARAMETERS
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 attribute-specific status of the cfg_sub-
sys_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.
DESCRIPTION
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 sub-
system 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.
EXAMPLES
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
");
break;
case CFG_ATTR_EOP:
printf("attribute does not allow this operation
");
break;
.
.
.
default:
printf("unknown error
");
break;
}
continue;
}
/* Display attribute value to application user */
printf ("%s
", 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() rou-
tine 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 appli-
cation displays the default value of attributes that return CFG_ATTR_SUCCESS.
RETURN VALUES
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).
RELATED INFORMATION
Commands: cfgmgr(8), sysconfig(8)
Routines: cfg_connect(3), cfg_subsys_defaults_all(3), libcfg(3)
Files: sysconfigtab(4) delim off
cfg_subsys_defaults(3)