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man pages section 3: Extended Library Functions, Volume 3

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Updated: Thursday, June 13, 2019
 
 

nvpair_name(3NVPAIR)

Name

nvlist_next_nvpair, nvpair_name, nvpair_type - return data regarding name-value pairs

Synopsis

cc [ flag... ] file... –lnvpair [ library... ]
#include <libnvpair.h>

nvpair_t *nvlist_next_nvpair(nvlist_t *nvl, nvpair_t *nvpair);
char *nvpair_name(nvpair_t *nvpair);
data_type_t nvpair_type(nvpair_t *nvpair);

Parameters

nvl

The nvlist_t to be processed.

nvpair

Handle to a name-value pair.

Description

The nvlist_next_nvpair() function returns a handle to the next nvpair in the list following nvpair. If nvpair is NULL, the first pair is returned. If nvpair is the last pair in the nvlist, NULL is returned.

The nvpair_name() function returns a string containing the name of nvpair.

The nvpair_type() function retrieves the value of the nvpair in the form of enumerated type data_type_t. This is used to determine the appropriate nvpair_*() function to call for retrieving the value.

Return Values

Upon successful completion, nvpair_name() returns a string containing the name of the name-value pair.

Upon successful completion, nvpair_type() returns an enumerated data type data_type_t. Possible values for data_type_t are as follows:

  • DATA_TYPE_BOOLEAN

  • DATA_TYPE_BOOLEAN_VALUE

  • DATA_TYPE_BYTE

  • DATA_TYPE_INT8

  • DATA_TYPE_UINT8

  • DATA_TYPE_INT16

  • DATA_TYPE_UINT16

  • DATA_TYPE_INT32

  • DATA_TYPE_UINT32

  • DATA_TYPE_INT64

  • DATA_TYPE_UINT64

  • DATA_TYPE_STRING

  • DATA_TYPE_NVLIST

  • DATA_TYPE_BOOLEAN_ARRAY

  • DATA_TYPE_BYTE_ARRAY

  • DATA_TYPE_INT8_ARRAY

  • DATA_TYPE_UINT8_ARRAY

  • DATA_TYPE_INT16_ARRAY

  • DATA_TYPE_UINT16_ARRAY

  • DATA_TYPE_INT32_ARRAY

  • DATA_TYPE_UINT32_ARRAY

  • DATA_TYPE_INT64_ARRAY

  • DATA_TYPE_UINT64_ARRAY

  • DATA_TYPE_STRING_ARRAY

  • DATA_TYPE_NVLIST_ARRAY

Upon reaching the end of a list, nvlist_next_pair() returns NULL. Otherwise, the function returns a handle to next nvpair in the list.

These and other libnvpair(3LIB) functions cannot manipulate nvpairs after they have been removed from or replaced in an nvlist. Replacement can occur during pair additions to nvlists created with NV_UNIQUE_NAME_TYPE and NV_UNIQUE_NAME. See nvlist_alloc(3NVPAIR).

Errors

No errors are defined.

Examples

Example 1 Example of usage of nvlist_next_nvpair().
/*
 * usage of nvlist_next_nvpair() 
 */
 static int 
 edit_nvl(nvlist_t *nvl) 
 {
     nvpair_t *curr = nvlist_next_nvpair(nvl, NULL); 
 
     while (curr != NULL) { 
         int err; 
        nvpair_t *next = nvlist_next_nvpair(nvl, curr); 
 
        if (!nvl_check(curr)) 
            if ((err = nvlist_remove(nvl, nvpair_name(curr), 
                nvpair_type(curr))) != 0) 
                    return (err); 
 
         curr = next; 
     } 
    return (0); 
 }

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
MT-Level
MT-Safe

See Also

libnvpair(3LIB), nvlist_alloc(3NVPAIR), attributes(7)

Notes

The enumerated nvpair data types might not be an exhaustive list and new data types can be added. An application using the data type enumeration, data_type_t, should be written to expect or ignore new data types.