M2-Planet/functions/file.c

104 lines
2.2 KiB
C

/* Copyright (C) 2016 Jeremiah Orians
* This file is part of M2-Planet.
*
* M2-Planet is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* M2-Planet is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with M2-Planet. If not, see <http://www.gnu.org/licenses/>.
*/
// CONSTANT stdin 0
// CONSTANT stdout 1
// CONSTANT stderr 2
// CONSTANT EOF 0xFFFFFFFF
int fgetc(FILE* f)
{
asm("LOAD_IMMEDIATE_eax %3"
"LOAD_EFFECTIVE_ADDRESS_ebx %4"
"LOAD_INTEGER_ebx"
"PUSH_ebx"
"COPY_esp_to_ecx"
"LOAD_IMMEDIATE_edx %1"
"INT_80"
"TEST"
"POP_eax"
"JUMP_NE8 !FUNCTION_fgetc_Done"
"LOAD_IMMEDIATE_eax %-1"
":FUNCTION_fgetc_Done");
}
void fputc(char s, FILE* f)
{
asm("LOAD_IMMEDIATE_eax %4"
"LOAD_EFFECTIVE_ADDRESS_ebx %4"
"LOAD_INTEGER_ebx"
"LOAD_EFFECTIVE_ADDRESS_ecx %8"
"LOAD_IMMEDIATE_edx %1"
"INT_80");
}
/* Important values needed for open
* O_RDONLY => 0
* O_WRONLY => 1
* O_RDWR => 2
* O_CREAT => 64
* O_TRUNC => 512
* S_IRWXU => 00700
* S_IXUSR => 00100
* S_IWUSR => 00200
* S_IRUSR => 00400
*/
FILE* open(char* name, int flag, int mode)
{
asm("LOAD_EFFECTIVE_ADDRESS_ebx %12"
"LOAD_INTEGER_ebx"
"LOAD_EFFECTIVE_ADDRESS_ecx %8"
"LOAD_INTEGER_ecx"
"LOAD_EFFECTIVE_ADDRESS_edx %4"
"LOAD_INTEGER_edx"
"LOAD_IMMEDIATE_eax %5"
"INT_80");
}
FILE* fopen(char* filename, char* mode)
{
FILE* f;
if('w' == mode[0])
{ /* 577 is O_WRONLY|O_CREAT|O_TRUNC, 384 is 600 in octal */
f = open(filename, 577 , 384);
}
else
{ /* Everything else is a read */
f = open(filename, 0, 0);
}
/* Negative numbers are error codes */
if(0 > f)
{
return 0;
}
return f;
}
int close(int fd)
{
asm("LOAD_EFFECTIVE_ADDRESS_ebx %4"
"LOAD_IMMEDIATE_eax %6"
"INT_80");
}
int fclose(FILE* stream)
{
int error = close(stream);
return error;
}