Thread: sscanf and parsing strings

  1. #1
    Registered User
    Join Date
    Feb 2008

    sscanf and parsing strings

    Hi all,

    This is my first post here so I don't know if it is a repost but I would appreciate any replies even if it is. I am writing a small command interpreter and after getting a line of input from the user I have to parse it to figure out which command was given. What I have now is as follows:

    //Inside loop getting info from the user
    char *infoa;
    char *infob;
    if (sscanf(line, "command option %s %s", infoa, infob) == 2){
       //Do the command
    There are then other sscanf if statements to check the other commands. The first issue is this is giving me a bus error when i type "command option a b" (a and b can be anything). If I change the %s to %d and the type of infoa and infob to ints, it works so why is it not working with strings? Secondly, I believe there must be a better way to parse strings but I have no idea what it is. If anyone can point me in a better direction, I would definately appreciate it.

    Thanks all

  2. #2
    Beautiful to C Aia's Avatar
    Join Date
    Jun 2007
    >If anyone can point me in a better direction
    pointing direction
    When the eagles are silent, the parrots begin to jabber. ~Winston Churchill

  3. #3
    Registered User
    Join Date
    Oct 2001
    Your pointers don't point anywhere.

    Make them arrays or allocate some memory and make them point there.

  4. #4
    Frequently Quite Prolix dwks's Avatar
    Join Date
    Apr 2005
    I'll have to point you in a cautionary direction:

    In other words, you can't store anything in a pointer that doesn't point to anything. You have to make it point somewhere -- by using dynamic memory allocation -- or use an array.

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
    "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
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  5. #5
    Registered User
    Join Date
    Feb 2008
    thanks for the responses. they were very helpful

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