C++Talk.NET C++ language newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  What is a good way to use c++ to delete all files in a direc          C++Talk.NET Forum Index -> C++ Language (Moderated) View previous topic :: View next topic   Author Message matoos80@hotmail.com Guest Posted: Tue Jun 07, 2005 10:55 pm    Post subject: What is a good way to use c++ to delete all files in a direc I'm developing a command-line program that needs to clear its temporary workspace and this involves deleting all previous files. Say the current working directory has all the temp-files ... I'm currently using: system("del *.dat"); but I would like to avoid the error message that occurs if there are no files of that type to delete. My problem is that I do not have advanced knowledge of the file names. So i cannot loop over a list of filename strings. Does anyone know of a better way of deleting all files in a directory without using the "del" system function like in DOS? Thanks, Matoos [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top 77123036@163.com Guest Posted: Wed Jun 08, 2005 7:54 am    Post subject: Re: What is a good way to use c++ to delete all files in a d if you have install "cygwin", you can use: system("rm *.dat"); [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top russelyang@gmail.com Guest Posted: Wed Jun 08, 2005 7:55 am    Post subject: Re: What is a good way to use c++ to delete all files in a d you can try system("del *.dat 1>NUL 2>NUL") [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Allan W Guest Posted: Wed Jun 08, 2005 7:56 am    Post subject: Re: What is a good way to use c++ to delete all files in a d [email]matoos80 (AT) hotmail (DOT) com[/email] wrote: Quote: I'm currently using: system("del *.dat"); but I would like to avoid the error message that occurs if there are no files of that type to delete. You're already non-portable, and that doesn't seem to bother you. So the best answer might also be system-dependant. Not sure what system you're on, but this might work on Windows (untested): system("del *.dat>nul"); Otherwise, you can just make sure that there is always at least one file of that type to delete! system("echo HELLO>killme.dat"); system("del *.dat"); The more-portable (but still not completely portable) way would be to use functions that look up the names of files in the current directory. Look at your system documentation for the names of functions and even code samples. One gotcha if you go this route: on some systems, if you look up the names of the files and delete them as you go, you won't get them all. Assume files are named FILE1 through FILE9 inclusive. You ask "what's the first file name that matches?" and you get FILE1. Now you delete FILE1. Next you ask "what's the second file name that matches?" But now the first file name that matches is FILE2, and the second name is FILE3. So you delete FILE3, but leave FILE2 alone. The answer to this problem (which doesn't happen on all OS's) is to first make a list of ALL files to delete, and THEN delete them. Good luck. [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Catalin Marinas Guest Posted: Wed Jun 08, 2005 12:21 pm    Post subject: Re: What is a good way to use c++ to delete all files in a [email]matoos80 (AT) hotmail (DOT) com[/email] wrote: Quote: I'm developing a command-line program that needs to clear its temporary workspace and this involves deleting all previous files. Say the current working directory has all the temp-files ... I'm currently using: system("del *.dat"); Have a look at the boost fs library. Maybe something like this: #include <boost/filesystem/operations.hpp> namespace fs = boost::filesystem; .... fs::remove_all(path) -- Catalin [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top msalters Guest Posted: Wed Jun 08, 2005 12:23 pm    Post subject: Re: What is a good way to use c++ to delete all files in a d [email]matoos80 (AT) hotmail (DOT) com[/email] schreef: Quote: I'm developing a command-line program that needs to clear its temporary workspace and this involves deleting all previous files. ... Does anyone know of a better way of deleting all files in a directory without using the "del" system function like in DOS? Have a look at boost(www.boost.org) FileSystem library. HTH, Michiel Salters [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Pete Becker Guest Posted: Thu Jun 09, 2005 9:40 am    Post subject: Re: What is a good way to use c++ to delete all files in a d [email]matoos80 (AT) hotmail (DOT) com[/email] wrote: Quote: system("del *.dat"); but I would like to avoid the error message that occurs if there are no files of that type to delete. Since nobody else has come up with the right answer <g>: system("if exist *.dat del *.dat") -- Pete Becker Dinkumware, Ltd. (http://www.dinkumware.com) [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top matoos Guest Posted: Thu Jun 09, 2005 9:43 am    Post subject: Re: What is a good way to use c++ to delete all files in a d Thanks all for the amazing feedback! For now, system("del *.dat 1>NUL 2>NUL") is working like a charm but I am also taking a look at the boost libraries. Portability isn't an issue for this design. I find the std library is pretty limited in terms of functions that create or check for the existence of files. You could use error flags to check for a file's existence, but then you end up doing a brute-force search by generating every possible string and checking error flags for those strings ... [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] Back to top Anand Hariharan Guest Posted: Fri Jun 10, 2005 10:28 am    Post subject: Re: What is a good way to use c++ to delete all files in a d Pete Becker wrote: Quote: matoos80 (AT) hotmail (DOT) com wrote: system("del *.dat"); but I would like to avoid the error message that occurs if there are no files of that type to delete. Since nobody else has come up with the right answer <g>: system("if exist *.dat del *.dat") How about - void main() {} ;-) - Anand [NB: Have seen the OP's most recent post] [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. 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