BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  va_arg question          BorlandTalk.com Forum Index -> C++ Builder (Language C++) View previous topic :: View next topic   Author Message py Guest Posted: Fri Nov 25, 2005 3:39 pm    Post subject: va_arg question Hello I want to pass va argss of a function as va argss of another function. how can I do that ? example: int func_1(...) { /*...*/ } int func_2(...) { /*...*/ } int func(bool x;...) { if (x) func_1(/*the va args*/); else func_2(/*the va args*/) } What must be the args when calling func_1 and func_2 ? Thank you s.pierre-yves (s.py) Back to top Liz Albin Guest Posted: Fri Nov 25, 2005 4:29 pm    Post subject: Re: va_arg question On Fri, 25 Nov 2005 16:39:15 +0100, py wrote: Quote: What must be the args when calling func_1 and func_2 ? How about looking up va_args in the help. There are examples of just what you're asking for -- liz Back to top py Guest Posted: Fri Nov 25, 2005 5:19 pm    Post subject: Re: va_arg question Thank you for the try, Liz but sounds like you missed my question. How about looking up the whole message before answering ? I obviously started with the help, and the vc help too, and search on the web etc. And finally I posted here. copy/past from borland help : #include <stdio.h> #include <stdarg.h> /* calculate sum of a 0 terminated list */ void sum(char *msg, ...) { int total = 0; va_list ap; int arg; va_start(ap, msg); while ((arg = va_arg(ap,int)) != 0) { total += arg; } printf(msg, total); va_end(ap); } int main(void) { sum("The total of 1+2+3+4 is %dn", 1,2,3,4,0); return 0; } Ok, nothing I don't know (in fact there is really few things which I do not know on c++ or pascal) My question is: having already va args in a function, how can I pass them to another function ? (note the 'already' word above) A more complete sample is here: int my_sprintf(char *buffer, const char *format[, argument, ...]) { if (is_std_format_specifiers(format)) return sprintf(buffer,format[,arguments,...]); // <<<<< HERE, how can I pass the whole 'argument(s)' to sprintf else { /* process the format string by hand */ }; } Note that watching the implementation of va_start,va_arg etc, the only solution i've found is by using 'naked' functions. what I m searching for is a portable way, if any exists. s.pierre-yves (s.py) "Liz Albin" 1oqjajo307nq0$.1or5i9y0bntlp.dlg (AT) 40tude (DOT) net... Quote: On Fri, 25 Nov 2005 16:39:15 +0100, py wrote: What must be the args when calling func_1 and func_2 ? How about looking up va_args in the help. There are examples of just what you're asking for -- liz Back to top Chris Uzdavinis (TeamB) Guest Posted: Fri Nov 25, 2005 5:32 pm    Post subject: Re: va_arg question "py" <spy200205 (AT) hotmail (DOT) com> writes: Quote: Thank you for the try, Liz but sounds like you missed my question. How about looking up the whole message before answering ? I obviously started with the help, and the vc help too, and search on the web etc. And finally I posted here. Take a look at the source to AnsiString. ($BCB6sourcevcldstring.cpp, I think) It has a member function called sprintf, which forwards its calls into the internal vsprintf function, I believe. That may be an example you can use. (I don't have it handy to check for myself, and don't do this sort of thing often enough to memorize it.) -- Chris (TeamB); Back to top Liz Albin Guest Posted: Fri Nov 25, 2005 6:11 pm    Post subject: Re: va_arg question On Fri, 25 Nov 2005 18:19:56 +0100, py wrote: Quote: (note the 'already' word above) Please try to be slightly less condescending. I presumed you knew enough to check the most common use of va_args: vsprintf. Here's the example from the online help: you get the arglist in a function, and pass that along. int vspf(char *fmt, ...) { va_list argptr; int cnt; va_start(argptr, fmt); cnt = vsprintf(buffer, fmt, argptr); va_end(argptr); return(cnt); } -- liz Back to top py Guest Posted: Fri Nov 25, 2005 8:39 pm    Post subject: Re: va_arg question "Liz Albin" <lizalbinNotThis (AT) yahoo (DOT) com> a écrit dans le message de news: o8x0xoybiyzo$.nj65kkodszwp$.dlg (AT) 40tude (DOT) net... Quote: On Fri, 25 Nov 2005 18:19:56 +0100, py wrote: (note the 'already' word above) Please try to be slightly less condescending. Yes ! I was (intentionnally) condescending, and even agitator, bc u was first - law of retaliation, I never fire first. Yes I neglected search on the bdn, bc I'm not accustomed to find there what I need. This time it was an error ok, but who never do ? Liz Albin wrote: Quote: How about looking up va_args in the help. There are examples of just what you're asking for -- liz but now peace and thanks for your last post :) s.pierre-yves (s.py) Back to top Liz Albin Guest Posted: Sat Nov 26, 2005 1:42 pm    Post subject: Re: va_arg question On Fri, 25 Nov 2005 21:39:11 +0100, py wrote: Quote: Yes ! I was (intentionnally) condescending, and even agitator, bc u was first - law of retaliation, I never fire first. Actually, I wasn't . I was terse. Had you looked through examples, and remembered printf and its cousins, you might have found a solution more quickly. Quote: Yes I neglected search on the bdn, bc I'm not accustomed to find there what I need. This time it was an error ok, but who never do ? I'm not sure why you're bringing up bdn, which is not whence the example came. Do yourself a favor, write conservatively, read forgivingly. Also, don't quote entire posts when you respond, trim to the relevent bits. Follow-up set to bpot. -- liz Back to top Remy Lebeau (TeamB) Guest Posted: Mon Nov 28, 2005 6:29 pm    Post subject: Re: va_arg question "py" <spy200205 (AT) hotmail (DOT) com> wrote Quote: My question is: having already va args in a function, how can I pass them to another function ? You pass in the va_list like you do any other function parameter value. Quote: if (is_std_format_specifiers(format)) return sprintf(buffer,format[,arguments,...]); how can I pass the whole 'argument(s)' to sprintf You cannot. You need to use vsprintf() instead of sprintf(). vsprintf() accepts a va_list as a parameter: int my_sprintf(char *buffer, const char *format, ...) { va_list ap; va_start(ap, format); int ret; if( is_std_format_specifiers(format) ) ret = vsprintf(buffer, format, ap); else { // process the format string by hand ... // ret = ...; } va_end(ap); return ret; } Gambit Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> C++ Builder (Language C++) All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.