diff options
Diffstat (limited to 'i386/dos/dos_open.c')
-rw-r--r-- | i386/dos/dos_open.c | 158 |
1 files changed, 0 insertions, 158 deletions
diff --git a/i386/dos/dos_open.c b/i386/dos/dos_open.c deleted file mode 100644 index 7e6ef2b..0000000 --- a/i386/dos/dos_open.c +++ /dev/null @@ -1,158 +0,0 @@ -/* - * Copyright (c) 1995-1994 The University of Utah and - * the Computer Systems Laboratory at the University of Utah (CSL). - * All rights reserved. - * - * Permission to use, copy, modify and distribute this software is hereby - * granted provided that (1) source code retains these copyright, permission, - * and disclaimer notices, and (2) redistributions including binaries - * reproduce the notices in supporting documentation, and (3) all advertising - * materials mentioning features or use of this software display the following - * acknowledgement: ``This product includes software developed by the - * Computer Systems Laboratory at the University of Utah.'' - * - * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS - * IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF - * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * - * CSL requests users of this software to return to csl-dist@cs.utah.edu any - * improvements that they make and grant CSL redistribution rights. - * - * Author: Bryan Ford, University of Utah CSL - */ - -#include <sys/types.h> -#include <sys/stat.h> -#include <fcntl.h> -#include <stdio.h> -#include <errno.h> - -#include "dos_io.h" -#include "vm_param.h" -#include "debug.h" - -int dos_open(const char *s, int flags, int mode, dos_fd_t *out_fh) -{ - struct real_call_data real_call_data; - int err = EINVAL; /*XXX*/ - vm_offset_t dos_buf_phys = (vm_offset_t)kvtophys(dos_buf); - - assert(dos_buf); assert(dos_buf_phys); - assert(dos_buf_phys < 0x100000); - - dos_init_rcd(&real_call_data); - - if (strlen(s)+1 > DOS_BUF_SIZE) - return E2BIG; - strcpy(dos_buf, s); - real_call_data.ds = dos_buf_phys >> 4; - real_call_data.edx = dos_buf_phys & 15; - - /* Possible situations: - - - 3d - C 3d || 3c - T 3d (ensure that it exists), close, 3c - CT 3c - X 3d - C X 3d (ensure that it doesn't exist), 3c - TX 3d (ensure that it exists), close, 3c - CTX 3d (ensure that it doesn't exist), 3c - */ - - if ((flags & (O_CREAT | O_EXCL | O_TRUNC)) != (O_CREAT | O_TRUNC)) - { - /* First try opening the file with function 0x3D. */ - real_call_data.eax = 0x3d40 | (flags & O_ACCMODE); - real_call_data.ecx = 0; - real_int(0x21, &real_call_data); - err = dos_check_err(&real_call_data); - if (!err) - *out_fh = real_call_data.eax & 0xffff; - } - - /* Now based on the result, determine what to do next. */ - switch (flags & (O_CREAT | O_EXCL | O_TRUNC)) - { - case 0: - case 0 | O_EXCL: - if (!err) - goto success; - else - return err; - case O_CREAT: - if (!err) - goto success; - else - break; - case O_CREAT | O_EXCL: - case O_CREAT | O_TRUNC | O_EXCL: - if (!err) - { - /* The file exists, but wasn't supposed to. - Close it and return an error. */ - dos_close(real_call_data.eax & 0xffff); - return EEXIST; - } - else - break; - case O_TRUNC: - case O_TRUNC | O_EXCL: - if (!err) - { - /* We've verified that the file exists - - now close it and reopen it with CREAT - so it'll be truncated as requested. */ - dos_close(real_call_data.eax & 0xffff); - break; - } - else - return err; - case O_CREAT | O_TRUNC: - /* This is the one case in which - we didn't try to open the file above at all. - Just fall on through and open it with CREAT. */ - break; - } - - /* Now try opening the file with DOS's CREAT call, - which truncates the file if it already exists. */ - real_call_data.eax = 0x3c00; - real_call_data.ecx = mode & S_IWUSR ? 0 : 1; - real_int(0x21, &real_call_data); - if (!(err = dos_check_err(&real_call_data))) - { - *out_fh = real_call_data.eax & 0xffff; - - /* We don't have to worry about O_APPEND here, - because we know the file starts out empty. */ - - return 0; - } - - return err; - - success: - - /* If the caller requested append access, - just seek to the end of the file once on open. - We can't implement full POSIX behavior here without help, - since DOS file descriptors don't have an append mode. - To get full POSIX behavior, - the caller must seek to the end of the file before every write. - However, seeking to the end only on open - is probably enough for most typical uses. */ - if (flags & O_APPEND) - { - vm_offset_t newpos; - err = dos_seek(*out_fh, 0, SEEK_END, &newpos); - if (err) - { - dos_close(*out_fh); - return err; - } - } - - return 0; -} - |