add text in existing file problam
in [Win32 API]
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From: B.S on 23 Oct 2009 16:58 I am tring to add some text in existing file but it doesn't work.I am using this code code: HANDLE hfile; DWORD din; TCHAR *programa[256]="some text"; TCHAR KEY[2]; hfile=CreateFile("file.txt",GENERIC_WRITE, 0,0,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0); int size=GetFileSize(hfile,0); SetFilePointer(hfile,size,0,FILE_BEGIN); WriteFile(hfile,programa,sizeof(programa),&din,0); SetFilePointer(hfile,size+sizeof(programa),0,FILE_BEGIN); WriteFile(hfile,KEY,2,&din,0); CloseHandle(hfile);
From: Seetharam on 23 Oct 2009 18:08 What do you mean by "doesn't work" ? Here is sample code in MSDN that writes to an existing file: http://msdn.microsoft.com/en-us/library/bb540534%28VS.85%29.aspx -Seetharam
From: ScottMcP [MVP] on 23 Oct 2009 18:32 On Oct 23, 4:58 pm, "B.S" <giobs...(a)gmail.com> wrote: > I am tring to add some text in existing file but it doesn't work.I am > using this code > > code: > > HANDLE hfile; > DWORD din; > > TCHAR *programa[256]="some text"; That is declared as an array of TCHAR*, not an array of char.
From: B.S on 24 Oct 2009 15:46 Seetharam wrote: > What do you mean by "doesn't work" ? > > Here is sample code in MSDN that writes to an existing file: > > http://msdn.microsoft.com/en-us/library/bb540534%28VS.85%29.aspx > > > -Seetharam I wont to write in existing file. I dont wont to creat new file.
From: r_z_aret on 24 Oct 2009 15:49
On Fri, 23 Oct 2009 13:58:52 -0700 (PDT), "B.S" <giobs111(a)gmail.com> wrote: >I am tring to add some text in existing file but it doesn't work.I am >using this code > >code: > >HANDLE hfile; >DWORD din; > >TCHAR *programa[256]="some text"; This won't compile if UNICODE is enabled when you compile. If you don't understand this statement than I strongly recommend avoiding TCHAR or taking time to understand UNICODE and TCHAR. Otherwise, you'll waste a lot of your time tracking down strange symptoms. >TCHAR KEY[2]; > hfile=CreateFile("file.txt",GENERIC_WRITE, >0,0,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0); This will also fail if UNICODE is enabled. >int size=GetFileSize(hfile,0); > >SetFilePointer(hfile,size,0,FILE_BEGIN); >WriteFile(hfile,programa,sizeof(programa),&din,0); sizeof( programa) is _not_ what you want here. You want the number of bytes in the string, not the size of the storage space. Especially when you defined the array wrong (see previous post). Also, if UNICODE is defined, number of bytes is not the same as number of characters. > >SetFilePointer(hfile,size+sizeof(programa),0,FILE_BEGIN); >WriteFile(hfile,KEY,2,&din,0); > >CloseHandle(hfile); ----------------------------------------- To reply to me, remove the underscores (_) from my email address (and please indicate which newsgroup and message). Robert E. Zaret, eMVP PenFact, Inc. 20 Park Plaza, Suite 400 Boston, MA 02116 www.penfact.com Useful reading (be sure to read its disclaimer first): http://catb.org/~esr/faqs/smart-questions.html |