Thread: lines in a file

  1. #1
    Registered User
    Join Date
    May 2004

    lines in a file

    OK last query of theday.

    Is there a way to obtain the number of lines in a file?

    I'm using

    fstream finput;, ios::in);
    read my file.

    I could just loop through to the end and increase a counter but this seems very inefficient, so thought there must be a better way


  2. #2
    and the hat of int overfl Salem's Avatar
    Join Date
    Aug 2001
    The edge of the known universe
    > I could just loop through to the end and increase a counter but this seems very inefficient
    Yes, that's pretty much the way you do it.

    Perhaps you should consider another approach, one which say doesn't rely on knowing the number of lines in advance. That way, you only read the file once instead of twice.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
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  3. #3
    Registered User manofsteel972's Avatar
    Join Date
    Mar 2004
    Just a quick note. I have been messing around with compiler options and the __LINE__ macro gives the line# on which it is placed I tried this

    unsigned long test=(unsigned long)__LINE__; cout<<test+otherfile; return 0;} //for main
    and then did a similar thing in each of the header files with a global variable. granted it counts white space and blank lines as well so it prolly isn't what your looking for but I just thought it was cool
    Last edited by manofsteel972; 09-29-2004 at 01:51 PM.
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  4. #4
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    May 2004
    Thanks for the response.

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