Skip to content

Update %Z specifier with known issue #4381

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 23, 2023
Merged

Update %Z specifier with known issue #4381

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion docs/c-runtime-library/format-specification-syntax-printf-and-wprintf-functions.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,7 @@ Integer types such as `short`, `int`, `long`, `long long`, and their `unsigned`
| **`p`** | Pointer type | Display the argument as an address in hexadecimal digits. |
| **`s`** | String | When used with `printf` functions, specifies a single-byte or multi-byte character string; when used with `wprintf` functions, specifies a wide-character string. Characters are displayed up to the first null character or until the *precision* value is reached. |
| **`S`** | String | When used with `printf` functions, specifies a wide-character string; when used with `wprintf` functions, specifies a single-byte or multi-byte character string. Characters are displayed up to the first null character or until the *precision* value is reached. |
| **`Z`** | `ANSI_STRING` or `UNICODE_STRING` structure | When the address of an [`ANSI_STRING`](/windows/win32/api/ntdef/ns-ntdef-string) or [`UNICODE_STRING`](/windows/win32/api/ntdef/ns-ntdef-_unicode_string) structure is passed as the argument, display the string contained in the buffer pointed to by the `Buffer` field of the structure. Use a *size* modifier prefix of **`w`** to specify a `UNICODE_STRING` argument—for example, `%wZ`. The `Length` field of the structure must be set to the length, in bytes, of the string. The `MaximumLength` field of the structure must be set to the length, in bytes, of the buffer.<br /><br />Typically, the **`Z`** type character is used only in driver debugging functions that use a conversion specification, such as `dbgPrint` and `kdPrint`. |
| **`Z`** | `ANSI_STRING` or `UNICODE_STRING` structure | **VS 2013 and earlier** <br /> When the address of an [`ANSI_STRING`](/windows/win32/api/ntdef/ns-ntdef-string) or [`UNICODE_STRING`](/windows/win32/api/ntdef/ns-ntdef-_unicode_string) structure is passed as the argument, display the string contained in the buffer pointed to by the `Buffer` field of the structure. Use a *size* modifier prefix of **`w`** to specify a `UNICODE_STRING` argument—for example, `%wZ`. The `Length` field of the structure must be set to the length, in bytes, of the string. The `MaximumLength` field of the structure must be set to the length, in bytes, of the buffer.<br /><br /> **Universal C Runtime (UCRT)**<br />There is a known issue in the UCRT that is currently maintained for compatibility. Like the **`S`** specifier, the **`Z`** specifier without a size modifier prefix refers to a `UNICODE_STRING` when using a narrow printing function (like `printf`) and an `ANSI_STRING` when using a wide printing function (like `wprintf`).<br /> Instead of **`Z`**, use **`hZ`** to specify an `ANSI_STRING`. **`wZ`** (or **`lZ`**) can still be used to specify a `UNICODE_STRING`. <br /><br />Typically, the **`Z`** type character is used only in driver debugging functions that use a conversion specification, such as `dbgPrint` and `kdPrint`. |

In Visual Studio 2015 and later versions, if the argument that corresponds to a floating-point conversion specifier (**`a`**, **`A`**, **`e`**, **`E`**, **`f`**, **`F`**, **`g`**, **`G`**) is infinite, indefinite, or NaN, the formatted output conforms to the C99 standard. This table lists the formatted output:

Expand Down