<?php

/*
  Linha de comando
  ipcs ->  mostra blocos de memoria alocados
  ipcrm -m "shmid" ->   remove o bloco de memória referenciado por shmid
 */

function ShmGetId($file) {
    if (!file_exists($file)) {
        touch($file);
    }
    return ftok($file, 'R');
}

function ShmOpen($key, $flags = SHM_ACESS_MODE, $mode = SHM_ACESS_PERMISSION, $size = SHM_SIZE) {
    $shmkey = shmop_open($key, $flags, $mode, $size);

    if (!$shmkey) {
        return false;
    } else {
        return $shmkey;
    }
}

function ShmWrite($shmkey, $data, $offset = 0) {
    $fsize = strlen($data);
    $shm_bytes_written = shmop_write($shmkey, $data, $offset);

    if ($shm_bytes_written != $fsize) {
        return false;
    } else {
        return $shm_bytes_written;
    }
}

function ShmRead($shmkey, $start, $count) {
    $my_string = shmop_read($shmkey, $start, $count);
    if (!$my_string) {
        return false;
    } else {
        return $my_string;
    }
}

function ShmWriteVar($shmkey, $data, $offset) {
    $fdata = serialize($fdata);
    $fsize = strlen($fdata);
    $shm_bytes_written = shmop_write($shmkey, $fdata, $offset);

    if ($shm_bytes_written != $fsize) {
        return false;
    } else {
        return $shm_bytes_written;
    }
}

function ShmReadVar($shmkey, $start, $count) {
    $my_string = shmop_read($shmkey, $start, $count);
    if (!$my_string) {
        return false;
    } else {
        return unserialize($my_string);
    }
}

function ShmDelete($shmkey) {
    if (!@shmop_delete($shmkey)) {
        return false;
    } else {
        return true;
    }
}

function ShmClose($shmkey) {
    return @shmop_close($shmkey);
}

function ShmExist($key) {
    return @shmop_open($key, 'a', 0, 0);
}

?>