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L in C

I am a novice C learner. And I don't have much advanced tutorial/
documentations on it too. yesterday i tried to write a windows console
timer program in C and i struck with some ...very unclear solutions....
(should say). First i was trying to write something on the title bar
of the consol window using following code:
LPWSTR sWTitle;
sWTitle = "my Title";
SetWindowsTitle(sWTitle);
Above code gave me some unknown characters in my console title bar.
Then I changed sWrite value with {L"my Title";} which performed
excatly as i needed. I added L unknowingly. Can you tell me what is
this L for? Is there any other `prefix/type caster/whatever`(i don't
know what it is called) in C? And one more... I used threads in my
program and i want it to be paused on some keyboard events without
interrupting another running threads. Is there a way to pause running
thread in C? Thanking you all for the reply in advance.
Aug 5 '08 #1
4 1571
|-|e|_|_ B0 wrote:
I am a novice C learner. And I don't have much advanced tutorial/
documentations on it too. yesterday i tried to write a windows console
timer program in C and i struck with some ...very unclear
solutions.... (should say). First i was trying to write something on
the title bar of the consol window using following code:
LPWSTR sWTitle;
sWTitle = "my Title";
SetWindowsTitle(sWTitle);
Above code gave me some unknown characters in my console title bar.
Then I changed sWrite value with {L"my Title";} which performed
excatly as i needed. I added L unknowingly. Can you tell me what is
this L for?
It isn't defined by Standard C.
Is there any other `prefix/type caster/whatever`(i don't
know what it is called) in C?
Prefix for what?

There are a number of conversion specifiers for the Standard I/O
functions, but if you are using a non-Standard function then you will
have to ask in a group for your system.
And one more... I used threads in my
program and i want it to be paused on some keyboard events without
interrupting another running threads. Is there a way to pause running
thread in C? Thanking you all for the reply in advance.
C doesn't even have the concept of threads.

You want <news:comp.os.ms-windows.programmer.win32>.

Aug 5 '08 #2
|-|e|_|_ B0 said:
I am a novice C learner. And I don't have much advanced tutorial/
documentations on it too. yesterday i tried to write a windows console
timer program in C and i struck with some ...very unclear solutions....
(should say). First i was trying to write something on the title bar
of the consol window using following code:
LPWSTR sWTitle;
sWTitle = "my Title";
SetWindowsTitle(sWTitle);
I'd be very surprised if that were true. Almost certainly, for example, the
third of those lines is mistyped.
Above code gave me some unknown characters in my console title bar.
Then I changed sWrite value with {L"my Title";} which performed
excatly as i needed.
Whether Windows API calls take wide strings or normal strings is, I
believe, dependent on a compiler setting. See my last paragraph, though.
I added L unknowingly. Can you tell me what is
this L for?
It allows you to specify a string literal that uses "wide characters" -
wchar_t characters - rather than ordinary chars. This allows you to use,
for example, Unicode characters in your program.
Is there any other `prefix/type caster/whatever`(i don't
know what it is called) in C? And one more... I used threads in my
program and i want it to be paused on some keyboard events without
interrupting another running threads. Is there a way to pause running
thread in C?
This is really a question about Windows rather than about C itself, so I
suggest you take it up in comp.os.ms-windows.programmer.win32 - which is
an excellent newsgroup for Windows questions, really first class.

--
Richard Heathfield <http://www.cpax.org.uk>
Email: -http://www. +rjh@
Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
"Usenet is a strange place" - dmr 29 July 1999
Aug 5 '08 #3
|-|e|_|_ B0Ý wrote:
I am a novice C learner. And I don't have much advanced tutorial/
documentations on it too.
You don't need "advanced tutorial/documentations". A simple elementary
C text and the FAQ for this news group should do the trick, except...
yesterday i tried to write a windows console
timer program in C and i struck with some ...very unclear solutions....
(should say).
suggests strongly that you are interested in Windows programming, using
a language that appears C-like but probably isn't.
First i was trying to write something on the title bar
of the consol window using following code:
LPWSTR sWTitle;
sWTitle = "my Title";
SetWindowsTitle(sWTitle);
LPWSTR means nothing in C. Unless it is a type pointer-to-char, the
assignment of the pointer to the anonymous string "my Title" is absurd.

SetWindowsTitle() means nothing in C.

It appears that you are using some implementation-specific types and
implementation-specific functions. You need to ask in a newsgroup for
your implementation. There is a good chance that it's one of the many
witn "windows", "microsoft", or "MSC" in their names.
Aug 5 '08 #4
|-|e|_|_ B0 wrote:
I am a novice C learner. And I don't have much advanced tutorial/
documentations on it too. yesterday i tried to write a windows console
timer program in C and i struck with some ...very unclear solutions....
(should say). First i was trying to write something on the title bar
of the consol window using following code:
LPWSTR sWTitle;
sWTitle = "my Title";
SetWindowsTitle(sWTitle);
Above code gave me some unknown characters in my console title bar.
Then I changed sWrite value with {L"my Title";} which performed
excatly as i needed. I added L unknowingly. Can you tell me what is
this L for? Is there any other `prefix/type caster/whatever`(i don't
know what it is called) in C?
You don't tell us what a LPWSTR* is, so anything here is a guess.

However, assuming they're using Microsoft's usual naming convention:

STR = string
W = wide
LP = long pointer

Most likely, LPWSTR* is just a fancy name for wchar_t*.

"my Title" is a narrow string. L"my Title" is a wide string. LPWSTR*
implies you want a pointer to the latter. If you assign a pointer to a
narrow string to a function expecting a pointer to a wide string, it's
not surprising at all that you strange results.

<OT>
Most Windows API functions are actually implemented as a pair of
functions, with A (ASCII) and U (Unicode) suffixes, and the unsuffixed
function name is actually an alias to one of them, which varies
depending on compiler options. If you want to pass a narrow string to
SetWindowTitle() when compiling in Unicode mode, you could probably use
SetWindowTitleA() -- but I don't know if the convention applies to that
particular function.

Typical Windows implementations also have a macro _T() which prefixes
its argument with L if compiling in Unicode mode. This is so you can
write SetWindowTitle(_T("my Title)); and it'd work in either mode.
</OT>
And one more... I used threads in my program and i want it to be paused
on some keyboard events without interrupting another running threads.
Is there a way to pause running thread in C? Thanking you all for the
reply in advance.
This is so far off-topic I can't even guess. You need to ask these
sorts of questions in a Windows-specific newsgroup.

S
Aug 5 '08 #5

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