/****************************************************************************
 * stickymap.c - re-run xmodmap on ACPI resume events                       *
 * Version: 0                                                               *
 *                                                                          *
 * Author: D J Capelis                                                      *
 * Contact: mail at capelis dot dj                                          *
 * Released to Public Domain, 2011.                                         *
 *                                                                          *
 * Disclaimer: I'm not responsible for anything at all not even a little.   *
 ***************************************************************************/

/* Documentation */
/* Compile: gcc -o stickymap stickymap.c */
/* Install: Copy it somewhere, chmod +x it */
/* Depends: libc, linux, acpid */
/* Run: Launch stickymap in the background via .xinitrc, it'll re-run xmodmap on ~/.Xmodmap 5 seconds after resume */

#include<stdlib.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<sys/un.h>
#include<pwd.h>
#include<unistd.h>
#include<stdio.h>
#include<errno.h>
#include<string.h>

#define chk_error(cond) if (cond) { goto err; }
#define BUFSIZE 1024

void handle_acpi_event(char * acpi_event);
char * cmd;

int main()
{
    struct passwd * user_ent;
    int buf_max;
    int acpid_sock;
    struct sockaddr_un * sockloc;
    char * parsebuffer;

    /* Setup string to pass to system() */
    user_ent = getpwuid(getuid());
    chk_error(user_ent == NULL);
    buf_max = sysconf(_SC_GETPW_R_SIZE_MAX);
    chk_error(buf_max < 1);
    cmd = calloc(1, 7 + 1 + buf_max + 9 + 1); // "xmodmap" + ' ' + homedir + "/.Xmodmap" + \0
    chk_error(cmd == NULL);
    cmd = strncat(cmd, "xmodmap ", 8);
    cmd = strncat(cmd, user_ent->pw_dir, buf_max);
    cmd = strncat(cmd, "/.Xmodmap", 9);

    /* Connect to acpid socket */
    acpid_sock = socket(AF_UNIX, SOCK_STREAM, 0);
    chk_error(acpid_sock < 0);
    sockloc = calloc(1, sizeof(struct sockaddr_un));
    chk_error(sockloc == NULL);
    sockloc->sun_family = AF_UNIX;
    strcpy(sockloc->sun_path,"/var/run/acpid.socket");
    chk_error(connect(acpid_sock, (struct sockaddr *) sockloc, 108) != 0);

    /* Parse the buffer and do the stuff */
    parsebuffer = calloc(1, BUFSIZE);
    while(1)
    {
        chk_error(read(acpid_sock, parsebuffer, BUFSIZE) < 0);
        handle_acpi_event(parsebuffer);
        memset(parsebuffer, 0, BUFSIZE);
    }

    /* Never reached */
    printf("stickymap is terminating, this shouldn't happen...\n");
    return -2;

err:
    perror("stickymap");
    return -1;
}

void handle_acpi_event(char * acpi_event)
{
    if(strncmp(acpi_event, "button/lid LID open", 19) == 0)
    {
        sleep(5); // Hope X picks up the keyboard within the first 5 seconds of resume
        chk_error(system(cmd) == -1);
    }

    return;

err:
    perror("stickymap");
    exit(-1);
}