- libbson 1.13.1 »
- API Reference »
- bson_iter_t

# bson_iter_init_from_data()

## Synopsis

    bool
    bson_iter_init_from_data (bson_iter_t *iter, const uint8_t *data, size_t length);

## Parameters

- `iter`: A bson_iter_t.
- `data`: A buffer to initialize with.
- `length`: The length of `data` in bytes.

## Description

The `bson_iter_init_from_data()` function shall initialize `iter` to iterate upon the buffer `data`, which must contain a BSON document. Upon initialization, `iter` is placed before the first element. Callers must call bson_iter_next(), bson_iter_find(), or bson_iter_find_case() to advance to an element.

## Returns

Returns true if the iter was successfully initialized.

## Example

    static void
    print_doc_id (const uint8_t *data, size_t length)
    {
       bson_iter_t iter;
       bson_oid_t oid;
       char oidstr[25];

       if (bson_iter_init_from_data (&iter, data, length) && bson_iter_find (&iter, "_id") &&
           BSON_ITER_HOLDS_OID (&iter)) {
          bson_iter_oid (&iter, &oid);
          bson_oid_to_string (&oid, oidstr);
          printf ("%s\n", oidstr);
       } else {
          printf ("Document is missing _id.\n");
       }
    }

### See Also:

bson_iter_init

bson_iter_init_find

bson_iter_init_find_case

bson_iter_init_find_w_len

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