Question

I have written a program that catches <ctrl> + <c> signals and then outputs a list, but I have one compile-time error that I can’t seem to get past. I keep receiving this error:

cannot convert `void ()()’ to `void (*)(int)’ in assignment

According to the compiler the error is happening at this line of code:

    handler.sa_handler = handle_SIGINT;

Here is the surrounding code as well:

cmdcounter = 1;

/*set up the signal handler*/
struct sigaction handler;
handler.sa_handler = handle_SIGINT;
sigaction(SIGINT, &handler, NULL);

strcpy(buffer, "Caught <ctrl><c>\n");

handle_SIGINT is defined earlier in the program:

void handle_SIGINT()
{
    write(STDOUT_FILENO, buffer, strlen(buffer));

    // Print out last 10 commands that were used.
    printf("Most recent commands entered:\n");
    if(cmdcounter <= 10) {
        for (i=0; i < cmdcounter; i++) {
            printf("%d. %s\n", i+1, cmd[i]);
        }
    }
    else {
        for (i = cmdcounter-10; i < cmdcounter; i++) {
            printf("%d. %f\n", i, cmd[i]);
        }
    }
}

Everything looks fine to me, but something is obviously not. Does anyone know what is throwing this error?

Answer 1

Your function handle_SIGINT is wrong.

Show us that function, and we’ll be able to tell you exactly how it is wrong.

handle_SIGINT is SUPPOSED to be:

void handle_SIGINT(int){....}

You left out the int part as a parameter.