kolibrios/programs/develop/metcc/trunk/libc/file/fopen.c

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#include "stdio.h"
#include "string.h"
FILE* fopen(const char* filename, const char *mode)
{
FILE* res;
int imode;
imode=0;
if (*mode=='r')
{
imode=FILE_OPEN_READ;
mode++;
}else if (*mode=='w')
{
imode=FILE_OPEN_WRITE;
mode++;
}else if (*mode=='a')
{
imode=FILE_OPEN_APPEND;
mode++;
}else
return 0;
if (*mode=='t')
{
imode|=FILE_OPEN_TEXT;
mode++;
}else if (*mode=='b')
mode++;
if (*mode=='+')
{
imode|=FILE_OPEN_PLUS;
mode++;
}
if (*mode!=0)
return 0;
res=malloc(sizeof(FILE));
res->buffer=0;
res->buffersize=0;
res->filesize=0;
res->filepos=0;
res->filename=0;
res->mode=imode;
//check if file exists
res=_msys_read_file(filename,0,0,0,&res->filesize);
if (res==5)
{
if ((imode & 3) == FILE_OPEN_READ)
{
free(res);
return 0;
}
res=_msys_write_file(filename,0,0);
if (res!=0)
{
free(res);
return 0;
}
res->filesize=0;
}
if (imode & 3==FILE_OPEN_WRITE)
{
res->buffersize=512;
res->buffer=malloc(res->buffersize);
if (res->buffer=0)
{
free(res);
return 0;
}
res->filesize=0;
}else
{
res->buffersize=(res->filesize & (~511))+512;
res->buffer=malloc(res->buffersize);
if (res->buffer==0)
{
free(res);
return 0;
}
res=_msys_read_file(filename,0,res->filesize,res->buffer,0);
if (res!=0)
{
free(res->buffer);
free(res);
}
if (imode & 3==FILE_OPEN_APPEND)
res->filepos=res->filesize;
}
res->filename=strdup(filename);
return res;
}