Linux Joystick Mapper Git

#include <ctype.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

int should_be_daemon = 0;


void set_daemonize(int set) {
    should_be_daemon = set;
}

int should_daemonize() {
    return should_be_daemon;
}

void kill_running_joymap() {
    char *home = getenv("HOME");
    char pid_file[1024];
    char exe_link[1024];
    char exe_file[1024];
    char digits[10];
    FILE *f;
    int i, count;
    int pid = 0;

    if (home == NULL) {
        return;
    }

    sprintf(pid_file, "%s/.joymap.pid", home);
    f = fopen(pid_file, "r");
    if (f != NULL) {
        count = fread(digits, 1, 10,  f);
        fclose(f);
        for (i=0; i<count && isdigit(digits[i]); i++) {
            pid = pid * 10;
            pid = pid + digits[i] - '0';
        }
    }

    if (pid == 0) {
        return;
    }
    sprintf(exe_link, "/proc/%d/exe", pid);
    if ((count = readlink(exe_link, exe_file, 1023)) < 0) {
        return;
    }
    if (strncmp(exe_file + count - 7, "loadmap", 7) != 0) {
        return;
    }
    kill(pid, SIGTERM);
    sleep(1);
}

void write_pid_file() {
    char *home = getenv("HOME");
    char pid_file[1024];
    FILE *f;

    if (home != NULL) {
        sprintf(pid_file, "%s/.joymap.pid", home);
        f = fopen(pid_file, "w");
        if (f != NULL) {
            fprintf(f, "%d", getpid());
            fclose(f);
        }
    }
}

void daemonize() {
    if (fork() == 0) {
        write_pid_file();
    } else {
        sleep(1);
        exit(0);
    }
}