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How to lock a file

 
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How to lock a file
no2pencil
11 Aug, 2008 - 06:24 PM
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I need to recreate an error. Without making a file read-only, how on a Windows System can I open/access the file to have it in a 'Locked' or 'in use' state?

I do not have access to a compiler, or rexx, but I do have access to mks tool kit (Korn Shell).

Basically, what is happening is the Virus Scanner is scanning the file at the specific moment that a process tries to write to it, & all hell breaks loose, so I just need a quick way to recreate the error.

Thanks everyone!
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Tom9729
RE: How To Lock A File
11 Aug, 2008 - 06:53 PM
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Would it be acceptable to just continuously write data to it with echo or something?
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no2pencil
RE: How To Lock A File
11 Aug, 2008 - 06:57 PM
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QUOTE(Tom9729 @ 11 Aug, 2008 - 10:53 PM) *

Would it be acceptable to just continuously write data to it with echo or something?

I need the file to be locked exclusively for writing by a process at the file system level.

Usually I just throw something together like this :

cpp

#include <stdio.h>

int main(void) {
  int ch=0;
  FILE * fp;

  fp=fopen("counter.txt", "w+");
  if(!fp) {
    printf("Failed to lock the file, now exiting.\n");
    return 1;
  }
  printf("File Locked...\n");

  while(ch!=12) {
    sleep(1);
  }
  fclose(fp);

  return 0;
}


But they don't have a compiler on this machine...
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Tom9729
RE: How To Lock A File
11 Aug, 2008 - 07:01 PM
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Could you download one?

TinyCC works just like GCC, and would easily fit on a flash drive or in a temp folder or something.

Edit: Actually I believe it would fit on a floppy if necessary.

This post has been edited by Tom9729: 11 Aug, 2008 - 07:02 PM
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no2pencil
RE: How To Lock A File
11 Aug, 2008 - 07:45 PM
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I was able to achieve this with Rexx.

CODE

/* Open "mytext.txt" for reading, but only if it exists */
IF STREAM('counter.txt', 'C', 'OPEN BOTH') == 'READY:' THEN DO

   SAY 'counter.txt exists'

   /* Here you can use CHARIN and LINEIN to read from the file */

  DO A = 1 TO 100 BY 1
  sleep 1
  END

END

/* File can't be opened. SAY why */
ELSE SAY STREAM('counter.txt', 'D')
RETURN
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Tom9729
RE: How To Lock A File
12 Aug, 2008 - 06:03 AM
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Cool, glad to hear you figured it out. icon_up.gif
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