//////////////////////////////////////////////////
    else if (op == MALC) { ax = (int)malloc(*sp);}
    else if (op == MSET) { ax = (int)memset((char *)sp[2], sp[1], *sp);}
    else if (op == MCMP) { ax = memcmp((char *)sp[2], (char *)sp[1], *sp);}


    ////////////// MY PART ///////////////////////////
    else if (op == TEMP)  { ax = m_sensor.GetDataByValType( num, SENS_VAL_TYPE_TEMP); }
    else if (op == HUM)  { ax = m_sensor.GetDataByValType( num, SENS_VAL_TYPE_HUM); }
}

// allocate memory for virtual machine
if (!(text = old_text = malloc(poolsize)))
    return -1;

if (!(data = malloc(poolsize))) 
    return -1;

if (!(stack = malloc(poolsize))) 
    return -1;

if (!(symbols = malloc(poolsize)))
    return -1;

memset(text, 0, poolsize);
memset(data, 0, poolsize);
memset(stack, 0, poolsize);
memset(symbols, 0, poolsize);
bp = sp = (int *)((int)stack + poolsize);
ax = 0;

src = "char else enum if int return sizeof while "
      "open read close printf malloc memset memcmp exit void main";

// add keywords to symbol table
i = Char;
while (i <= While) 
{
    next();
    current_id[Token] = i++;
}

// add library to symbol table
i = OPEN;
while (i <= EXIT) 
{
    next();
    current_id[Class] = Sys;
    current_id[Type] = INT;
    current_id[Value] = i++;
}

next(); current_id[Token] = Char;
next(); idmain = current_id; 

 program();

g++ xc.c
xc.c: In function 'long long int eval()':
xc.c:83:62: error: 'open' was not declared in this scope
         else if (op == OPEN) { ax = open((char *)sp[1], sp[0]); }
                                                              ^
xc.c:84:46: error: 'close' was not declared in this scope
         else if (op == CLOS) { ax = close(*sp);}
                                              ^
xc.c:85:67: error: 'read' was not declared in this scope
         else if (op == READ) { ax = read(sp[2], (char *)sp[1], *sp); }
                                                                   ^
xc.c: In function 'int main(int, char**)':
xc.c:112:28: error: 'open' was not declared in this scope
     if ((fd = open(*argv, 0)) < 0) {
                            ^
xc.c:117:42: error: invalid conversion from 'void*' to 'char*' [-fpermissive]
     if (!(src = old_src = malloc(poolsize))) {
                                          ^
xc.c:122:38: error: 'read' was not declared in this scope
     if ((i = read(fd, src, poolsize-1)) <= 0) {
                                      ^
xc.c:127:13: error: 'close' was not declared in this scope
     close(fd);
             ^
xc.c:130:44: error: invalid conversion from 'void*' to 'long long int*' [-fpermissive]
     if (!(text = old_text = malloc(poolsize))) {
                                            ^
xc.c:134:33: error: invalid conversion from 'void*' to 'char*' [-fpermissive]
     if (!(data = malloc(poolsize))) {
                                 ^
xc.c:138:34: error: invalid conversion from 'void*' to 'long long int*' [-fpermissive]
     if (!(stack = malloc(poolsize))) {

PS C:\Users\AlexC\Documents\GitHub\write-a-C-interpreter> gcc -m32 -o xc xc.c
xc.c: In function 'next':
xc.c:111:57: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
                 if (current_id[Hash] == hash && !memcmp((char *)current_id[Name], last_pos, src - last_pos)) {
                                                         ^
xc.c:121:32: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
             current_id[Name] = (int)last_pos;
                                ^
xc.c:188:29: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
                 token_val = (int)last_pos;
                             ^
xc.c: In function 'expression':
xc.c:363:30: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
             data = (char *)(((int)data + sizeof(int)) & (-sizeof(int)));
                              ^
xc.c:363:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
             data = (char *)(((int)data + sizeof(int)) & (-sizeof(int)));
                    ^
xc.c:629:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
                 *addr = (int)(text + 3);
                         ^
xc.c:633:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
                 *addr = (int)(text + 1);
                         ^
.....

PS C:\Users\AlexC\Documents\compiler> gcc -m32 .\compiler.c .\helloworld.c
.\compiler.c: In function 'main':
.\compiler.c:46:15: warning: implicit declaration of function 'open' [-Wimplicit-function-declaration]
     if ((fd = open(*argv, 0)) < 0) {
               ^~~~
.\compiler.c:56:14: warning: implicit declaration of function 'read' [-Wimplicit-function-declaration]
     if ((i = read(fd, src, poolsize-1)) <= 0) {
              ^~~~
.\compiler.c:61:5: warning: implicit declaration of function 'close' [-Wimplicit-function-declaration]
     close(fd);

#include <fcntl.h> // for open
#include <unistd.h> // for close

int main(int argc, char *argv[])
{
    size_t linecap = 0;
    ssize_t linelen;
    while ((linelen = getline(&line, &linecap, stdin)) > 0) {
        src = line;
        next();
        printf("%d\n", expr());
    }
    return 0;
}