File handle functions | Forex Factory

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File handle functions

  • #1
  • First Post: Nov 7, 2013 2:20pm Nov 7, 2013 2:20pm
...
Inserted Code
      int handle = FileOpen(fileName,FILE_CSV|FILE_READ |FILE_WRITE,",");
      Print(FileReadString(handle) + " File Handle: " + handle);
      int pos = FileTell(handle);
      Print("Before: " + pos);
      FileFlush(handle);
      Print("After Flush: " + FileTell(handle));
      FileSeek(handle,pos,SEEK_SET);
      Print("End: " + FileTell(handle));

2013.11.07 21:15:31 File Writing GBPUSD,H4: 0 File Handle: 1
2013.11.07 21:15:31 File Writing GBPUSD,H4: Before: -89
2013.11.07 21:15:31 File Writing GBPUSD,H4: After Flush: 1102
2013.11.07 21:15:31 File Writing GBPUSD,H4: End: 1102

0 is indeed the first value in the file.

Can someone tell me why I get a negative file position at the very beginning? I just want to jump back to the position I was before flushing. Where did I make the obvious mistake I am not seeing?
  • #2
  • Nov 7, 2013 2:43pm Nov 7, 2013 2:43pm
Quoting Kilian19
... int handle = FileOpen(fileName,FILE_CSV|FILE_READ |FILE_WRITE,","); Print(FileReadString(handle) + " File Handle: " + handle); int pos = FileTell(handle); Print("Before: " + pos); FileFlush(handle); Print("After Flush: " + FileTell(handle)); FileSeek(handle,pos,SEEK_SET); Print("End: " + FileTell(handle)); 2013.11.07 21:15:31 File Writing GBPUSD,H4: 0 File Handle: 1 2013.11.07 21:15:31 File Writing GBPUSD,H4: Before: -89 2013.11.07 21:15:31 File Writing GBPUSD,H4: After Flush: 1102 2013.11.07 21:15:31 File Writing GBPUSD,H4: End: 1102 0 is indeed...
Use the get lasterror function after opening the file and after reading the position. The 0 value could be because the file didn't open and not a value read
  • #3
  • Nov 7, 2013 2:48pm Nov 7, 2013 2:48pm
Quoting MaxDoom
{quote} Use the get lasterror function after reading the position
No error occurs.. That is the problem. A negative offset is wrong in the first place isn't it?
  • #4
  • Nov 7, 2013 2:53pm Nov 7, 2013 2:53pm
Quoting Kilian19
{quote} No error occurs.. That is the problem. A negative offset is wrong in the first place isn't it?
I will have a look tomorrow for you if you have not solved before
  • #5
  • Nov 7, 2013 2:58pm Nov 7, 2013 2:58pm
Quoting MaxDoom
{quote} I will have a look tomorrow for you if you have not solved before
FileSeek(handle,0,SEEK_CUR);

will set the pointer to the end in an instant. It might be a windows related issue as I don't have administrator access in the folders and everything gets temporarily saved at "C:\\Users\\Kilian\\AppData\\Local\\VirtualStore\\Program Files (x86)\\MetaTrader - Alpari UK\\experts\\files\\Tester.csv"
I am just surprised that reading and writing to the file works like a charm ...
  • #6
  • Last Post: Nov 8, 2013 1:44am Nov 8, 2013 1:44am
Quoting Kilian19
{quote} FileSeek(handle,0,SEEK_CUR); will set the pointer to the end in an instant. It might be a windows related issue as I don't have administrator access in the folders and everything gets temporarily saved at "C:\Users\Kilian\AppData\Local\VirtualStore\Program Files (x86)\MetaTrader - Alpari UK\experts\files\Tester.csv" I am just surprised that reading and writing to the file works like a charm ...
Hil Kilian

I think that you might be right, it all works fine for me

try installing MT4 outside of c:\program files

also you could try running MT4 as administrator when you launch the program.
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