# `./fio-stl/004 urlencoded.h`

3 public symbols.

### Types

#### `fio_url_encoded_parser_callbacks_s`

```c
typedef struct {
/**
* Called for each name=value pair found.
*
* `name` and `value` point directly into the original input data.
* The data is NOT decoded - caller must decode if needed.
*
* Returns the (possibly updated) udata, or NULL to stop parsing.
*/
void *(*on_pair)(void *udata, fio_buf_info_s name, fio_buf_info_s value);
/**
* Called on parsing error (optional).
*
* Currently not used since URL-encoded parsing is very permissive,
* but reserved for future use.
*/
void (*on_error)(void *udata);
} fio_url_encoded_parser_callbacks_s
```

The URL-encoded parser callbacks.

Callbacks receive `udata` as their first argument.

_Symbol type:_ `type`

#### `fio_url_encoded_result_s`

```c
typedef struct {
/** Number of bytes consumed from the buffer. */
size_t consumed;
/** Number of name=value pairs found. */
size_t count;
/** Non-zero if an error occurred (callback returned NULL). */
int err;
} fio_url_encoded_result_s
```

The URL-encoded parse result type.

_Symbol type:_ `type`

### Functions

#### `fio_url_encoded_parse`

```c
fio_url_encoded_result_s fio_url_encoded_parse(const fio_url_encoded_parser_callbacks_s *callbacks, void *udata, const char *data, size_t len)
```

Parse URL-encoded data from buffer.

`callbacks` contains the callback functions (should be static const).
`udata` is user data passed to callbacks.
`data` is the URL-encoded data to parse.
`len` is the length of the data.

Returns a result struct containing:
- `consumed`: Number of bytes consumed from the buffer
- `count`: Number of name=value pairs found
- `err`: Non-zero if parsing was stopped (callback returned NULL)

Parsing rules:
- Pairs are separated by `&`
- Name and value are separated by `=`
- Empty value is valid: `name=` → value.len = 0
- Missing `=` means value is empty: `name` → name="name", value.len = 0
- Empty name with value: `=value` → name.len = 0, value="value"
- Empty pairs (`&&`) are skipped

Note: The parser does NOT decode percent-encoded characters.
Use `fio_string_write_url_dec` to decode if needed.

_Symbol type:_ `function`

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