C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Portable way to retrieve path separator Goto page 1, 2, 3  Next          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message Matthias Hofmann Guest Posted: Tue Sep 06, 2005 4:07 pm    Post subject: Portable way to retrieve path separator Hello everyone! I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. The standard says nothing about path separators, and I found no information on the internet either. If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? What I have in mind is something like this: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif However, as far as I know the message pragma is not portable. -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Victor Bazarov Guest Posted: Wed Sep 07, 2005 12:56 am    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. The standard says nothing about path separators, and I found no information on the internet either. The Standard says nothing because the system doesn't have to have any "paths" and hence nothing like "path separator" can be standardized. Quote: If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? Tell them to supply it. Quote: What I have in mind is something like this: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif However, as far as I know the message pragma is not portable. Right, it's not. V [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Russell Hind Guest Posted: Wed Sep 07, 2005 12:57 am    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: Hello everyone! I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. The standard says nothing about path separators, and I found no information on the internet either. If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? What I have in mind is something like this: Have you looked at boost::filesystem library? http://www.boost.org/libs/filesystem/doc/index.htm Cheers Russell [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Ulrich Eckhardt Guest Posted: Wed Sep 07, 2005 1:05 am    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif #if defined(WIN32) || defined(_WIN32) # define PATH_SEPARATOR "\" #else # error "Could not determine path separator." #endif Uli -- Questions ? see C++-FAQ Lite: http://parashift.com/c++-faq-lite/ first ! [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Carl Barron Guest Posted: Wed Sep 07, 2005 1:06 am    Post subject: Re: Portable way to retrieve path separator In article <431d82af$0$2110$9b4e6d93 (AT) newsread2 (DOT) arcor-online.net>, Matthias Hofmann <hofmann (AT) anvil-soft (DOT) com> wrote: Quote: Hello everyone! I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. The standard says nothing about path separators, and I found no information on the internet either. If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? What I have in mind is something like this: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif However, as far as I know the message pragma is not portable. replace #pragma messsage with #error Could not determine path separator is easiest solution. #error generates a complier error with the text after #error on the same line. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Greg Herlihy Guest Posted: Wed Sep 07, 2005 9:58 am    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: Hello everyone! I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. The standard says nothing about path separators, and I found no information on the internet either. If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? What I have in mind is something like this: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif However, as far as I know the message pragma is not portable. Actually, Windows will accept the slash character in either direction as a file system delimiter (see below). But the issue is not necessarily OS-dependent since the delimiter could depend on the format of the volume being accessed The good news is that there there is a portable way to specify file path names, just not one that C++ provides. As far as I know #include directives are about the only place where file system paths would have much bearing on a C++ program. But the C++ Standard leaves the interpretation of an include directive open. It simply states that the mapping between the the contents of the include directive and the local file system is implementation-defined. But as long as the C++ program can check the system APIs for POSIX compliance at runtime, then the program can call POSIX routines with POSIX compliant path names (which look like traditional UNIX paths). Most of the popular OSes including Windows, Linux, and MacOS X do have POSIX APIs for accessing their file systems; so a portable implementation in C++ should be possible. Greg [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top ThosRTanner Guest Posted: Wed Sep 07, 2005 10:08 am    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: Hello everyone! I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. The standard says nothing about path separators, and I found no information on the internet either. Acutally, windows32 will let you use / as a path separator, so as long as you intend to use only windows or unix, you needn't worry. Quote: If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? What I have in mind is something like this: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif However, as far as I know the message pragma is not portable. To what precisely? [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top kanze Guest Posted: Wed Sep 07, 2005 10:08 am    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: I wonder if there is a portable way to retrieve the platform-dependant path separator. Windows uses '' while Linux uses '/', and other platforms might still use other characters. Windows uses both. If you're parsing pathnames, you have to accept both '/' and '' as path separators. If you're displaying pathnames, '' is preferred. Quote: The standard says nothing about path separators, and I found no information on the internet either. If there is no way to tell the path separator, then can anyone please tell me a portable way to make clients of my code aware of the problem? What I have in mind is something like this: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif However, as far as I know the message pragma is not portable. Never heard of it. And what happens when you have twenty different systems, with twenty different attributes. The usual solution is to create a system dependant include file for each system, which contains all of this sort of information. Things like: static char const GB_optId = '-' ; // - under UNIX static char const GB_altOptId = '+' ; // + under UNIX static char const GB_asciiEsc = '\' ; // under UNIX static char const GB_preferredPathSep = '/' ; // / under UNIX static char const GB_allowedPathSep[] = "/" ; static bool const GB_ignoreCase = false ; // in filenames only. static char const GB_stdinName[] = "-" ; static int const GB_exitSuccess = 0 ; static int const GB_exitWarning = 1 ; static int const GB_exitError = 2 ; static int const GB_exitFatal = 3 ; static int const GB_exitInternal = 4 ; This version is for Unix based systems. For Windows, GB_allowedPathSep becomes "/\". Put the version for each system in a separate directory, and use -I to select at compile time. (Your compiler invocation is pretty system dependant anyway, so adding a system dependant option to it won't change much.) -- James Kanze GABI Software Conseils en informatique orientée objet/ Beratung in objektorientierter Datenverarbeitung 9 place Sémard, 78210 St.-Cyr-l'École, France, +33 (0)1 30 23 00 34 [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Matthias Hofmann Guest Posted: Wed Sep 07, 2005 5:14 pm    Post subject: Re: Portable way to retrieve path separator "Greg Herlihy" <greghe (AT) pacbell (DOT) net> schrieb im Newsbeitrag news:1126048768.497680.4010 (AT) g14g2000cwa (DOT) googlegroups.com... Quote: Most of the popular OSes including Windows, Linux, and MacOS X do have POSIX APIs for accessing their file systems; so a portable implementation in C++ should be possible. What I actually want to do is take the __FILE__ predefined macro and cut off the path in front of the filename, so that "C:MyDocumentsMyProjectmain.cpp" turns into "main.cpp". In order to achieve this, I usually write code like the following: char* cutoff_path( char* p ) { char* _p; if ( ( _p = strrchr( p, '\' ) ) != NULL ) p = _p + 1; return p; } However, it seems to be a bad idea to hard code the backslash if you want to be portable. -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Matthias Hofmann Guest Posted: Wed Sep 07, 2005 5:16 pm    Post subject: Re: Portable way to retrieve path separator "ThosRTanner" <ttanner2 (AT) bloomberg (DOT) net> schrieb im Newsbeitrag news:1126082481.385997.154230 (AT) g47g2000cwa (DOT) googlegroups.com... Quote: However, as far as I know the message pragma is not portable. To what precisely? Actually to any platform that supports C++, although I mainly use Windows. Nevertheless, I want to make my code available to other people as well, and they might use systems of any kind. -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Matthias Hofmann Guest Posted: Wed Sep 07, 2005 5:19 pm    Post subject: Re: Portable way to retrieve path separator "Carl Barron" <cbarron413 (AT) adelphia (DOT) net> schrieb im Newsbeitrag news:060920051629433708%cbarron413 (AT) adelphia (DOT) net... Quote: In article <431d82af$0$2110$9b4e6d93 (AT) newsread2 (DOT) arcor-online.net>, However, as far as I know the message pragma is not portable. replace #pragma messsage with #error Could not determine path separator is easiest solution. #error generates a complier error with the text after #error on the same line. Is #error a platform independent directive? It is not even listed in the MSDN-Library, but maybe I simply oversaw it. -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Matthias Hofmann Guest Posted: Wed Sep 07, 2005 5:20 pm    Post subject: Re: Portable way to retrieve path separator "Russell Hind" <rh_gmane (AT) mac (DOT) com> schrieb im Newsbeitrag news:dfkfjh$p0l$1$8300dec7 (AT) news (DOT) demon.co.uk... Quote: Have you looked at boost::filesystem library? http://www.boost.org/libs/filesystem/doc/index.htm No, but this looks very interesting, thank you for this link. However, it would be great if my code would not require separate libraries. -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Matthias Hofmann Guest Posted: Wed Sep 07, 2005 5:21 pm    Post subject: Re: Portable way to retrieve path separator "Ulrich Eckhardt" <doomster (AT) knuut (DOT) de> schrieb im Newsbeitrag news:3o6db5F4fdbtU2 (AT) uni-berlin (DOT) de... Quote: Matthias Hofmann wrote: #ifdef _WIN32 #define PATH_SEPARATOR "\" #else #pragma message ( "Could not determine path separator." ) #endif #if defined(WIN32) || defined(_WIN32) # define PATH_SEPARATOR "\" #else # error "Could not determine path separator." #endif Thank you, that looks promising. Is there a list of macros for other systems, like Linux or Mac? -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Matthias Hofmann Guest Posted: Wed Sep 07, 2005 5:21 pm    Post subject: Re: Portable way to retrieve path separator "Victor Bazarov" <v.Abazarov (AT) comAcast (DOT) net> schrieb im Newsbeitrag news:bqjTe.33701$Tf5.22212 (AT) newsread1 (DOT) mlpsca01.us.to.verio.net... Quote: The Standard says nothing because the system doesn't have to have any "paths" and hence nothing like "path separator" can be standardized. The standard also uses locales to support internationalization, though the system does not have to have formats for the display of date and time. All that would be required is a function that returns a character, which would be the implementation-dependent path separator. -- Matthias Hofmann Anvil-Soft, CEO http://www.anvil-soft.com - The Creators of Klomanager http://www.anvil-soft.de - Die Macher des Klomanagers [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Bjorn Reese Guest Posted: Wed Sep 07, 2005 7:09 pm    Post subject: Re: Portable way to retrieve path separator Matthias Hofmann wrote: Quote: Thank you, that looks promising. Is there a list of macros for other systems, like Linux or Mac? http://predef.sourceforge.net/ -- mail1dotstofanetdotdk [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         C++Talk.NET Forum Index -> C++ Language (Moderated) All times are GMT Goto page 1, 2, 3  Next Page 1 of 3   Jump to: Select a forum C/C++----------------C LanguageC Language (Moderated)C++ Language (Moderated)C++ language (comp.lang.c++)C++ language, library and standards Non-English C/C++ Newsgroups----------------C++ (German)C++ (French)  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.