GLib.String.prepend_len

### Method

# GLib Stringprepend_len

#### Declaration

    GString*
    g_string_prepend_len (
      GString* string,
      const gchar* val,
      gssize len
    )

#### Description

Prepends `len` bytes of `val` to `string`.

If `len` is positive, `val` may contain embedded nuls and need not be nul-terminated. It is the caller’s responsibility to ensure that `val` has at least `len` addressable bytes.

If `len` is negative, `val` must be nul-terminated and `len` is considered to request the entire string length. This makes `g_string_prepend_len()` equivalent to g_string_prepend().

#### Parameters

`val`

  Type: `const gchar*`

  Bytes to prepend.

  The data is owned by the caller of the method.
  The value is a NUL terminated UTF-8 string.

`len`

  Type: `gssize`

  Number of bytes in `val` to prepend, or -1 for all of `val`.

#### Return value

Type: `GString`

`string`.

The data is owned by the instance.