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Internals of the printf function?
Post 302417819 by Christian.B on Saturday 1st of May 2010 02:19:16 AM
05-01-2010
Internals of the printf function?
hey all, im a new programmer.
i was wondering how you would go about writing the printf function yourself? it is my understanding that when you call printf you are calling an already written function and just providing an argument? if this is the case, is it possible to write that function yourself with just the bare primitives of the language? i only want to know because i am curious about how things like that work.
---------- Post updated 05-01-10 at 01:19 AM ---------- Previous update was 04-30-10 at 10:05 PM ----------
just to update, i've researched that the gcc compiler is written mostly in C, and so it's likely that the code for all these built-in c functions are written in C as well. so i take that to mean i could somehow write a printf-like function.
i suppose my best bet would be to look at the gcc source and just find it. however, not being a good programmer yet ( i only started just last week), i have no idea where i would find it
. if anyone could point me in the right direction, or explain how i might write it, i would be very happy
i was wondering how you would go about writing the printf function yourself? it is my understanding that when you call printf you are calling an already written function and just providing an argument? if this is the case, is it possible to write that function yourself with just the bare primitives of the language? i only want to know because i am curious about how things like that work.
---------- Post updated 05-01-10 at 01:19 AM ---------- Previous update was 04-30-10 at 10:05 PM ----------
just to update, i've researched that the gcc compiler is written mostly in C, and so it's likely that the code for all these built-in c functions are written in C as well. so i take that to mean i could somehow write a printf-like function.
i suppose my best bet would be to look at the gcc source and just find it. however, not being a good programmer yet ( i only started just last week), i have no idea where i would find it
. if anyone could point me in the right direction, or explain how i might write it, i would be very happy |
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winegcc
WINEGCC(1) Wine Developers Manual WINEGCC(1) NAME
winegcc - Wine C and C++ MinGW Compatible Compiler SYNOPSIS
winegcc [options] infile... DESCRIPTION
winegcc is a gcc wrapper which tries to provide a MinGW compatible compiler under Linux. This is most useful to Win32 developers who can simply take their MinGW code from Windows, and recompile it without modifications under Winelib on Linux. wineg++ accepts mostly the same options as winegcc. The goal of winegcc is to be able to simply replace gcc/g++/windres with winegcc/wineg++/wrc in a MinGW Makefile, and just recompile the application using Winelib under Wine. While typically there are small adjustments that must be made to the application source code and/or Makefile, it is quite easy to do them in a fashion that is compatible between the MinGW and Wine environments. This manual will document only the differences from gcc; please consult the gcc manual for more information on those options. OPTIONS
gcc options: All gcc options are supported, and are passed along to the backend compiler. -Bprefix This option specifies where to find the executables, libraries, include files, and data files of the compiler itself. This is a standard gcc option that has been extended to recognize a prefix ending with '/tools/winebuild', in which case winegcc enters a spe- cial mode for building Wine itself. Developers should avoid prefixes ending with the magic suffix, or if that is not possible, sim- ply express it differently, such as '/tools/winebuild/', to avoid the special behaviour. -fno-short-wchar Override the underlying type for wchar_t to be the default for the target, instead of using short unsigned int, which is the default for Win32. -mconsole This option passes '--subsystem console' to winebuild, to build console applications. It is the default. -mno-cygwin Use Wine's implementation of MSVCRT, instead of linking against the host system's libc. This is necessary for the vast majority of Win32 applications, as they typically depend on various features of MSVCRT. This switch is also used by the MinGW compiler to link against MSVCRT on Windows, instead of linking against Cygwin's libc. Sharing the syntax with MinGW makes it very easy to write Make- files that work under Wine, MinGW+MSYS, or MinGW+Cygwin. -municode Set the default entry point of the application to be the Unicode wmain() instead of the standard main(). -mwindows This option adds -lgdi32, -lcomdlg32, and -lshell32 to the list of default libraries, and passes '--subsystem windows' to winebuild to build graphical applications. -nodefaultlibs Do not use the standard system libraries when linking. These include at a minimum -lkernel32, -luser32, -ladvapi32, and any default libraries used by the backend compiler. The -mwindows option augments the list of default libraries as described above. -nostartfiles Do not add the winecrt0 library when linking. -Wb,option Pass option as an option to winebuild. If option contains commas, it is split into multiple options at the commas. DEFINES
winegcc defines __WINE__, for code that needs to know when it is being compiled under Wine. It also defines WIN32, _WIN32, __WIN32, __WIN32__, __WINNT, and __WINNT__ for compatibility with MinGW. BUGS
The dllimport/dllexport attributes are not supported at the moment, due to lack of support for these features in the ELF version of gcc. Static linking is not currently supported against Wine's DLL. As a result, the -static, --static, and -Wl,-static options will generate an error. AUTHORS
winegcc was written by Dimitrie O. Paun. SEE ALSO
gcc(1), winebuild(1), wrc(1), wine(1), Winelib User Guide, Wine Developers Guide. Wine 1.2-rc6 October 2005 WINEGCC(1)