Create a file in DOS??

This is a discussion on Create a file in DOS?? within the A Brief History of Cprogramming.com forums, part of the Community Boards category; I need to create a file from within a batch file, but I can't find a DOS command anywhere that ...

  1. #1
    Guest Sebastiani's Avatar
    Join Date
    Aug 2001
    Location
    Waterloo, Texas
    Posts
    5,670

    Create a file in DOS??

    I need to create a file from within a batch file, but I can't find a DOS command anywhere that does this. For now, I'm just redirecting a single character to the file (and thus creating it) - ugly hack, right?

    Cheers.



    ITSA
    Socket Library!

  2. #2
    and the hat of wrongness Salem's Avatar
    Join Date
    Aug 2001
    Location
    The edge of the known universe
    Posts
    32,452
    Just a guess

    copy nul myfile
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  3. #3
    Guest Sebastiani's Avatar
    Join Date
    Aug 2001
    Location
    Waterloo, Texas
    Posts
    5,670
    Nope (but nice try).

    OK, ugly hack #2:

    type nul > myfile

    ...dos sucks.
    Last edited by Sebastiani; 03-14-2004 at 02:10 AM.



    ITSA
    Socket Library!

  4. #4
    Super Moderator VirtualAce's Avatar
    Join Date
    Aug 2001
    Posts
    9,590
    Look up DOS interrupt 21h in Ralph Brown's Interrupt List.

  5. #5
    Guest Sebastiani's Avatar
    Join Date
    Aug 2001
    Location
    Waterloo, Texas
    Posts
    5,670
    You can call an interrupt from a batch file?



    ITSA
    Socket Library!

  6. #6
    End Of Line Hammer's Avatar
    Join Date
    Apr 2002
    Posts
    6,231
    >>I need to create a file from within a batch file
    And you can't write a program to do that for you (create the file)?

    >>copy nul myfile
    ... as expected, this works for me. What errors do you get?

    >>type nul > myfile
    ... would've been my second choice after copy.
    When all else fails, read the instructions.
    If you're posting code, use code tags: [code] /* insert code here */ [/code]

  7. #7
    Super Moderator VirtualAce's Avatar
    Join Date
    Aug 2001
    Posts
    9,590
    Well no, but creating a file from within a batch file does not fall under DOS programming. That falls more under what can be done in DOS from a user viewpoint rather than what can be accomplished in code under DOS.


    edit <some_name>.bat



    There are several batch commands for you to use inside of batch files. Look up DOS 6.22 batch commands on www.google.com and you will find all of em.

  8. #8
    Guest Sebastiani's Avatar
    Join Date
    Aug 2001
    Location
    Waterloo, Texas
    Posts
    5,670
    >> And you can't write a program to do that for you (create the file)?

    I'm invoking a chain of compilation tools, the file in question gets created/destroyed somewhat dynamically.

    >>copy nul myfile

    All I get is '(0) Files copied' and no file.

    Anyway, thanks for all of the suggestions.



    ITSA
    Socket Library!

  9. #9
    Super Moderator VirtualAce's Avatar
    Join Date
    Aug 2001
    Posts
    9,590
    Gimme more info Sebastiani and I can help. If anything I could code a simple program in C that could invoke DOS int 21h to do this for you.

  10. #10
    and the hat of wrongness Salem's Avatar
    Join Date
    Aug 2001
    Location
    The edge of the known universe
    Posts
    32,452
    Well if you're going to the trouble of writing an external program, then a simple
    fclose(fopen("file","w"));
    type hack seems to be easy enough.

    The 'touch' program on linux is a more capable version, and there are ports to the MS world.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. To find the memory leaks without using any tools
    By asadullah in forum C Programming
    Replies: 2
    Last Post: 05-12-2008, 07:54 AM
  2. Need Help Fixing My C Program. Deals with File I/O
    By Matus in forum C Programming
    Replies: 7
    Last Post: 04-29-2008, 07:51 PM
  3. Can we have vector of vector?
    By ketu1 in forum C++ Programming
    Replies: 24
    Last Post: 01-03-2008, 04:02 AM
  4. Inventory records
    By jsbeckton in forum C Programming
    Replies: 23
    Last Post: 06-28-2007, 04:14 AM
  5. Replies: 3
    Last Post: 03-04-2005, 01:46 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21