Thread: execl failing

  1. #1
    carrythe0
    Guest

    Thumbs down execl failing

    I am trying to run execl from a child process. it runs another program I wrote called producer, which takes two parameters: a single char and an int. the producer program is in the same directory as the parent. here is what I have:

    if(fork() == 0){
    if((execl("./producer", "producer", 'A', 0, NULL)) == -1){
    perror("execl failed");
    exit(1);
    }

    there are actually two producers, A and B, and when I run the program, I get these error messages:

    execl producer A failed: bad address
    execl producer B failed: bad address

    why?

  2. #2
    and the hat of int overfl Salem's Avatar
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    All the args should be const char *'s

    'A' is an integer, which when cast to a pointer will be something like 0x00000041 (this isn't good).

    So
    if((execl("./producer", "producer", "A", "0", NULL)) == -1){

    In your producer, which has
    int main ( int argc, char *argv[] ).....
    argv[0] == "producer"
    argv[1] == "A"
    argv[2] == "0"
    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.

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