mirror of https://github.com/FreeRDP/FreeRDP
132 lines
6.0 KiB
Markdown
132 lines
6.0 KiB
Markdown
|
# Print Format Specifiers
|
||
|
|
|
||
|
|
## Lookup Table
|
||
|
|
|
||
|
|
We use the following format specifiers for all \*printf\* and WLog_* functions:
|
||
|
|
|
||
|
|
| Type | signed | unsigned | octal | hex | HEX |
|
||
|
|
| ------------------ | --------- | --------- | --------- | --------- | --------- |
|
||
|
|
| signed char | %hhd | | | | |
|
||
|
|
| unsigned char | | %hhu | %hho | %hhx | %hhX |
|
||
|
|
| short | %hd | | | | |
|
||
|
|
| unsigned short | | %hu | %ho | %hx | %hX |
|
||
|
|
| int | %d | | | | |
|
||
|
|
| unsigned int | | %u | %o | %x | %X |
|
||
|
|
| long | %ld | | | | |
|
||
|
|
| unsigned long | | %lu | %lo | %lx | %lX |
|
||
|
|
| long long | %lld | | | | |
|
||
|
|
| unsigned long long | | %llu | %llo | %llx | %llX |
|
||
|
|
| size_t | | %"PRIuz" | %"PRIoz" | %"PRIxz" | %"PRIXz" |
|
||
|
|
| INT8 | %"PRId8" | | | | |
|
||
|
|
| UINT8 | | %"PRIu8" | %"PRIo8" | %"PRIx8" | %"PRIX8" |
|
||
|
|
| BOOLEAN | | %"PRIu8" | %"PRIo8" | %"PRIx8" | %"PRIX8" |
|
||
|
|
| BYTE | | %"PRIu8" | %"PRIo8" | %"PRIx8" | %"PRIX8" |
|
||
|
|
| CHAR | %"PRId8" | | | | |
|
||
|
|
| UCHAR | | %"PRIu8" | %"PRIo8" | %"PRIx8" | %"PRIX8" |
|
||
|
|
| INT16 | %"PRId16" | | | | |
|
||
|
|
| UINT16 | | %"PRIu16" | %"PRIo16" | %"PRIx16" | %"PRIX16" |
|
||
|
|
| WORD | | %"PRIu16" | %"PRIo16" | %"PRIx16" | %"PRIX16" |
|
||
|
|
| WCHAR | | %"PRIu16" | %"PRIo16" | %"PRIx16" | %"PRIX16" |
|
||
|
|
| SHORT | %"PRId16" | | | | |
|
||
|
|
| USHORT | | %"PRIu16" | %"PRIo16" | %"PRIx16" | %"PRIX16" |
|
||
|
|
| INT32 | %"PRId32" | | | | |
|
||
|
|
| UINT32 | | %"PRIu32" | %"PRIo32" | %"PRIx32" | %"PRIX32" |
|
||
|
|
| INT | %"PRId32" | | | | |
|
||
|
|
| UINT | | %"PRIu32" | %"PRIo32" | %"PRIx32" | %"PRIX32" |
|
||
|
|
| LONG | %"PRId32" | | | | |
|
||
|
|
| HRESULT | %"PRId32" | | | %"PRIx32" | %"PRIX32" |
|
||
|
|
| NTSTATUS | %"PRId32" | | | %"PRIx32" | %"PRIX32" |
|
||
|
|
| ULONG | | %"PRIu32" | %"PRIo32" | %"PRIx32" | %"PRIX32" |
|
||
|
|
| DWORD | | %"PRIu32" | %"PRIo32" | %"PRIx32" | %"PRIX32" |
|
||
|
|
| DWORD32 | | %"PRIu32" | %"PRIo32" | %"PRIx32" | %"PRIX32" |
|
||
|
|
| BOOL | %"PRId32" | | | | |
|
||
|
|
| INT64 | %"PRId64" | | | | |
|
||
|
|
| LONG64 | %"PRId64" | | | | |
|
||
|
|
| LONGLONG | %"PRId64" | | | | |
|
||
|
|
| UINT64 | | %"PRIu64" | %"PRIo64" | %"PRIx64" | %"PRIX64" |
|
||
|
|
| ULONG64 | | %"PRIu64" | %"PRIo64" | %"PRIx64" | %"PRIX64" |
|
||
|
|
| ULONGLONG | | %"PRIu64" | %"PRIo64" | %"PRIx64" | %"PRIX64" |
|
||
|
|
| DWORDLONG | | %"PRIu64" | %"PRIo64" | %"PRIx64" | %"PRIX64" |
|
||
|
|
| QWORD | | %"PRIu64" | %"PRIo64" | %"PRIx64" | %"PRIX64" |
|
||
|
|
| ULONG64 | | %"PRIu64" | %"PRIo64" | %"PRIx64" | %"PRIX64" |
|
||
|
|
|
||
|
|
|
||
|
|
## Pointers
|
||
|
|
|
||
|
|
When printing pointers you should cast the argument to ``(void*)``:
|
||
|
|
|
||
|
|
```c
|
||
|
|
rdpContext *pContext;
|
||
|
|
fprintf(stderr, "rdp context is %p\n", (void*) pContext);
|
||
|
|
```
|
||
|
|
|
||
|
|
If you need more formatting options cast the pointer argument to `size_t` and use
|
||
|
|
any %"PRI*z" format specifier:
|
||
|
|
|
||
|
|
```c
|
||
|
|
rdpContext *pContext;
|
||
|
|
fprintf(stderr, "rdp context is %" PRIuz " (0x%" PRIXz ")\n", (size_t) pContext, (size_t) pContext);
|
||
|
|
```
|
||
|
|
|
||
|
|
|
||
|
|
## Integer Promotion
|
||
|
|
|
||
|
|
Remember that integer types smaller than int are promoted when an operation is
|
||
|
|
performed on them.
|
||
|
|
|
||
|
|
Wrong:
|
||
|
|
|
||
|
|
```c
|
||
|
|
UINT8 a, b;
|
||
|
|
fprintf(stderr, "a - b is %" PRIu8 "\n", a - b);
|
||
|
|
// depending on the system's PRIu8 definition you might get:
|
||
|
|
// warning: format specifies type 'unsigned char' but the argument has type 'int'
|
||
|
|
```
|
||
|
|
|
||
|
|
Correct:
|
||
|
|
|
||
|
|
```c
|
||
|
|
UINT8 a, b;
|
||
|
|
fprintf(stderr, "a - b is %d\n", a - b);
|
||
|
|
// or ...
|
||
|
|
fprintf(stderr, "a - b is %" PRIu8 "\n", (UINT8) (a - b));
|
||
|
|
```
|
||
|
|
|
||
|
|
## TCHAR
|
||
|
|
|
||
|
|
When using `_tprintf` or similar TCHAR formatting functions or macros you
|
||
|
|
need to enclose the PRI format defines:
|
||
|
|
|
||
|
|
```c
|
||
|
|
LPCTSTR lpFileName1;
|
||
|
|
UINT64 fileSize1;
|
||
|
|
|
||
|
|
_tprintf(_T("The size of %s is %") _T(PRIu64) _T("\n"), lpFileName1, fileSize1);
|
||
|
|
```
|
||
|
|
|
||
|
|
Since this makes the strings a lot harder to read try to avoid _tprintf if the
|
||
|
|
arguments don't contain TCHAR types.
|
||
|
|
|
||
|
|
Note: If all compilers were C99 compliant we could simply write ...
|
||
|
|
|
||
|
|
```c
|
||
|
|
_tprintf(_T("The size of %s is %") PRIu64 "\n"), lpFileName1, fileSize1);
|
||
|
|
```
|
||
|
|
|
||
|
|
... since the standard says that only one of the character sequences must be
|
||
|
|
prefixed by an encoding prefix and the rest of them are treated to have the
|
||
|
|
same. However, Microsoft Visual Studio versions older than VS 2015 are not C99
|
||
|
|
compliant in this regard.
|
||
|
|
|
||
|
|
See [How to use stdint types with _tprintf in Visual Studio 2013](http://stackoverflow.com/questions/41126081/how-to-use-stdint-types-with-tprintf-in-visual-studio-2013)
|
||
|
|
for more information.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
## Links
|
||
|
|
|
||
|
|
- [[MS-DTYP] 2.2 Common Data Types](https://msdn.microsoft.com/en-us/library/cc230309.aspx)
|
||
|
|
- [Understand integer conversion rules](https://www.securecoding.cert.org/confluence/display/c/INT02-C.+Understand+integer+conversion+rules)
|
||
|
|
- [Printf format strings](https://en.wikipedia.org/wiki/Printf_format_string)
|
||
|
|
- [C data types - Basic Types](https://en.wikipedia.org/wiki/C_data_types#Basic_types)
|