Read first line of a file and store in a variable

This is a discussion on Read first line of a file and store in a variable within the C Programming forums, part of the General Programming Boards category; Dear friends, I have a file named "in.txt" with following data: 10 20 30 40 and now I want to ...

  1. #1
    Registered User
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    May 2009
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    Read first line of a file and store in a variable

    Dear friends,

    I have a file named "in.txt" with following data:

    10
    20
    30
    40


    and now I want to store the first line of this file which is "10" in a variable of type integer. would you please help with this? so that after running the program lets say variable "nFirst" equals to "10".

    Regrads.

  2. #2
    and the Hat of Guessing tabstop's Avatar
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    Which part of the problem is the problem? Do you know how to do input in general? Do you know how to open a file? What?

  3. #3
    Registered User slingerland3g's Avatar
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    Please google around and read up on fgets() and fopen(). This may point you in the right direction to learn how to open up a file and get its contents.

  4. #4
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    u can wrote it like this
    tag
    #include<stdio.h>
    main()
    {
    FILE *o;
    o=fopen("in.txt","r");
    if((o=fopen("in.txt","r"))!=NULL)
    {
    int x;
    fscanf(o,"%d",&x);
    printf("nfirst = %d",x);
    fclose(o);
    }
    }
    tag

  5. #5
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    @mustafa:

    It's better to give them a hint, and let them work at it for awhile. If our plumbers can't work with toilets, I don't want them to be plumbers.

    Instead of tag, try:

    [code1]
    Code:
    Your code in here
    [/code1]

    Just leave off the 1, to make it work.

  6. #6
    Frequently Quite Prolix dwks's Avatar
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    Canada
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    Instead of saying "tag", you can use the real code tags, [code] [/code]

    Also, doesn't it seem a bit strange to name an input file "o"? . . . .

    [edit] @Adak: try [noparse][code] [/code][/noparse] to display what you intend. [/edit]
    dwk

    Seek and ye shall find. quaere et invenies.

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