Files
oldlinux-files/docs/interrupts/int-html/rb-2779.htm
2024-02-19 00:23:35 -05:00

285 lines
16 KiB
HTML

<HTML>
<HEAD>
<TITLE>Int 21/AH=3Dh
</TITLE>
<META NAME="Description" CONTENT="
Int 21/AH=3Dh - DOS 2+ - OPEN - OPEN EXISTING FILE -
AH = 3Dh
AL = access and sharing modes (see #01402)
DS:DX - ASCIZ filename
CL = attribute mask of files to look for (server call only)
Return: CF clear if successful
AX = file handle
CF set on error
AX = error code (01h,02h,03h,04h,05h,0Ch,56h) (see #01680 at AH=59h)
Notes: file pointer is set to start of file
if SHARE or a network is loaded, the file open may fail if the file
">
<META NAME="robots" CONTENT="none">
</HEAD>
<BODY BGCOLOR="#FFD0A0">
<center>
<h2>Int 21/AH=3Dh
</h2>
</center><p>
<table border=1 cellpadding=3 cellspacing=1>
<td>
<a href="rb-2778.htm" tppabs="http://www.ctyme.com/intr/rb-2778.htm">
<img src="lup.gif" tppabs="http://graphics.ctyme.com/gif/lup.gif" border=0 alt=Prev></a>
<a href="rb-2780.htm" tppabs="http://www.ctyme.com/intr/rb-2780.htm">
<img src="ldown.gif" tppabs="http://graphics.ctyme.com/gif/ldown.gif" border=0 alt=Next></a>
<a href="javascript:if(confirm('http://www.ctyme.com/rbrown.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/rbrown.htm'" tppabs="http://www.ctyme.com/rbrown.htm">
<img src="lhome.gif" tppabs="http://graphics.ctyme.com/gif/lhome.gif" border=0 alt=Ralf Brown Page></a>
<td><a href="int.htm" tppabs="http://www.ctyme.com/intr/int.htm">Interrups</a></td>
<td><a href="cat.htm" tppabs="http://www.ctyme.com/intr/cat.htm">Categories</a></td>
<td><a href="alpha.htm" tppabs="http://www.ctyme.com/intr/alpha.htm">Contents</a></td>
</td></table><p>
<p><img src="rbline.gif" tppabs="http://graphics.ctyme.com/gif/rbline.gif" width="100%" alt="------"><p>
<h3><font color=#C00040>DOS 2+ - OPEN - OPEN EXISTING FILE</font></h3>
<PRE>
AH = 3Dh
AL = access and sharing modes <a href="rb-2779.htm#Table1402" tppabs="http://www.ctyme.com/intr/rb-2779.htm#Table1402">(see #01402)</a>
DS:DX -> ASCIZ filename
CL = attribute mask of files to look for (server call only)<br>
<p><b>Return:</b><br>CF clear if successful
AX = file handle
CF set on error
AX = error code (01h,02h,03h,04h,05h,0Ch,56h) <a href="javascript:if(confirm('http://www.ctyme.com/intr/rb-0000.htm \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/intr/rb-0000.htm#Table0'" tppabs="http://www.ctyme.com/intr/rb-0000.htm#Table0"></a>(see #01680 at AH=59h)
</PRE>
<p><b>Notes:</b>
File pointer is set to start of file.
If SHARE or a network is loaded, the file open may fail if the file
is already open, depending on the combination of sharing modes
<a href="javascript:if(confirm('http://www.ctyme.com/intr/rb-0000.htm \n\nThis file was not retrieved by Teleport Pro, because it was unavailable, or its retrieval was aborted, or the project was stopped too soon. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/intr/rb-0000.htm#Table0'" tppabs="http://www.ctyme.com/intr/rb-0000.htm#Table0"></a>(see #01403,#01404).
File handles which are inherited from a parent also inherit sharing
and access restrictions.
Files may be opened even if given the hidden or system attributes.
Under the FlashTek X-32 DOS extender, the pointer is in DS:EDX.
DR DOS checks the system password or explicitly supplied password at
the end of the filename (following a semicolon) against the reserved
field in the directory entry before allowing access.
Sharing modes are only effective on local drives if SHARE is loaded
<p><b>BUG:</b>
Novell DOS 7 SHARE v1.00 would refuse file access in the cases in
#01403 marked with [1] (read-only open of a read-only file
which had previously been opened in compatibility mode); this was
fixed in SHARE v1.01 of 09/29/94
<p><b>See Also:</b>
<a href="rb-2574.htm" tppabs="http://www.ctyme.com/intr/rb-2574.htm">AH=0Fh</a> - <a href="rb-2778.htm" tppabs="http://www.ctyme.com/intr/rb-2778.htm">AH=3Ch</a> - <a href="rb-2803.htm" tppabs="http://www.ctyme.com/intr/rb-2803.htm">AX=4301h</a> - <a href="rb-3017.htm" tppabs="http://www.ctyme.com/intr/rb-3017.htm">AX=5D00h</a> - <a
<PRE>
<p>
Bitfields for access and sharing modes:
<a name=table1402></a>
Bit(s) Description (Table 01402)
2-0 access mode.
000 read only.
001 write only.
010 read/write.
011 (DOS 5+ internal) passed to redirector on EXEC to allow
case-sensitive filenames
3 reserved (0)
6-4 sharing mode (DOS 3.0+) <a href="rb-2779.htm#Table1403" tppabs="http://www.ctyme.com/intr/rb-2779.htm#Table1403">(see #01403)</a>.
000 compatibility mode.
001 "DENYALL" prohibit both read and write access by others.
010 "DENYWRITE" prohibit write access by others.
011 "DENYREAD" prohibit read access by others.
100 "DENYNONE" allow full access by others.
111 network FCB (only available during server call)
7 inheritance.
If set, file is private to current process and will not be inherited
by child processes
</PRE>
<p><b>See Also:</b>
#01782 - #01403
<PRE>
<p>
<a name=table1403></a>
(Table 01403)
Values of DOS 2-6.22 file sharing behavior:
| Second and subsequent Opens
First |Compat Deny Deny Deny Deny
Open | All Write Read None
|R W RW R W RW R W RW R W RW R W RW
- - - - -| - - - - - - - - - - - - - - - - -
Compat R |Y Y Y N N N 1 N N N N N 1 N N.
W |Y Y Y N N N N N N N N N N N N.
RW|Y Y Y N N N N N N N N N N N N
- - - - -|
Deny R |C C C N N N N N N N N N N N N
All W |C C C N N N N N N N N N N N N.
RW|C C C N N N N N N N N N N N N
- - - - -|
Deny R |2 C C N N N Y N N N N N Y N N
Write W |C C C N N N N N N Y N N Y N N.
RW|C C C N N N N N N N N N Y N N
- - - - -|
Deny R |C C C N N N N Y N N N N N Y N
Read W |C C C N N N N N N N Y N N Y N.
RW|C C C N N N N N N N N N N Y N
- - - - -|
Deny R |2 C C N N N Y Y Y N N N Y Y Y
None W |C C C N N N N N N Y Y Y Y Y Y.
RW|C C C N N N N N N N N N Y Y Y
<p><b>Legend:</b><br>Y = open succeeds, N = open fails with error code 05h.
C = open fails, INT 24 generated.
1 = open succeeds if file read-only, else fails with error code.
2 = open succeeds if file read-only, else fails with INT 24
</PRE>
<p><b>See Also:</b>
#01636 - #01404
<PRE>
<p>
<a name=table1404></a>
(Table 01404)
Values for DOS 7.x file sharing behavior:
| Second and subsequent Opens
First |Compat Deny Deny Deny Deny
Open | All Write Read None
|R W RW A R W RW A R W RW A R W RW A R W RW A
- - - - -| - - - - - - - - - - - - - - - - - - - - - - - -
Compat R |Y Y Y Y N N N N Y N N Y N N N Y Y N N Y.
W |Y Y Y C N N N N N N N N N N N Y Y N N Y.
RW|Y Y Y C N N N N N N N N N N N Y Y N N Y.
NA|Y C C Y N N N N Y N N Y N N N Y Y N N Y
- - - - -|
Deny R |C C C C N N N N N N N N N N N N N N N N
All W |C C C C N N N N N N N N N N N N N N N N.
RW|C C C C N N N N N N N N N N N N N N N N.
NA|C C C C N N N N N N N N N N N N N N N N
- - - - -|
Deny R |Y C C Y N N N N Y N N Y N N N Y Y N N Y
Write W |C C C C N N N N N N N N Y N N Y Y N N Y.
RW|C C C C N N N N N N N N N N N Y Y N N Y.
NA|Y C C Y N N N N Y N N Y N N N Y Y N N Y
- - - - -|
Deny R |C C C C N N N N N Y N N N N N N N Y N N
Read W |C C C C N N N N N N N N N Y N N N Y N N.
RW|C C C C N N N N N N N N N N N N N Y N N.
NA|Y Y Y Y N N N N Y Y Y Y N N N Y Y Y Y Y
- - - - -|
Deny R |Y Y Y Y N N N N Y Y Y Y N N N Y Y Y Y Y
None W |C C C C N N N N N N N N Y Y Y Y Y Y Y Y.
RW|C C C C N N N N N N N N N N N Y Y Y Y Y.
NA|Y Y Y Y N N N N Y Y Y Y N N N Y Y Y Y Y
<p><b>Legend:</b><br>R -> reading, W -> writing, RW -> both reading & writing,.
A/NA -> reading without access time update.
Y = open succeeds, N = open fails with error code 05h.
C = open fails, INT 24 generated
</PRE>
<p><b>See Also:</b>
#01403 - #01636
<p>
<b>Category: <a href="cat-010.htm" tppabs="http://www.ctyme.com/intr/cat-010.htm">
DOS Kernel</a>
- <a href="int-21.htm" tppabs="http://www.ctyme.com/intr/int-21.htm">
Int 21h</a>
- <a href="alpha-d.htm" tppabs="http://www.ctyme.com/intr/alpha-d.htm">
D</a>
</b><p><p><img src="rbline.gif" tppabs="http://graphics.ctyme.com/gif/rbline.gif" width="100%" alt="------"><p>
<table border=1 cellpadding=3 cellspacing=1>
<td>
<a href="rb-2778.htm" tppabs="http://www.ctyme.com/intr/rb-2778.htm">
<img src="lup.gif" tppabs="http://graphics.ctyme.com/gif/lup.gif" border=0 alt=Prev></a>
<a href="rb-2780.htm" tppabs="http://www.ctyme.com/intr/rb-2780.htm">
<img src="ldown.gif" tppabs="http://graphics.ctyme.com/gif/ldown.gif" border=0 alt=Next></a>
<a href="javascript:if(confirm('http://www.ctyme.com/rbrown.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/rbrown.htm'" tppabs="http://www.ctyme.com/rbrown.htm">
<img src="lhome.gif" tppabs="http://graphics.ctyme.com/gif/lhome.gif" border=0 alt=Ralf Brown Page></a>
<td><a href="int.htm" tppabs="http://www.ctyme.com/intr/int.htm">Interrups</a></td>
<td><a href="cat.htm" tppabs="http://www.ctyme.com/intr/cat.htm">Categories</a></td>
<td><a href="alpha.htm" tppabs="http://www.ctyme.com/intr/alpha.htm">Contents</a></td>
</td></table><p>
<!-- Bottom Link Start -->
<center>
<p><table border=1 bgcolor="#ffff99"><tr><td>
<table border=0 height=80>
<tr align=center><td width="65">
<a href="javascript:if(confirm('http://www.ctyme.com/sponsor.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/sponsor.htm'" tppabs="http://www.ctyme.com/sponsor.htm">
<img src="tip.gif" tppabs="http://graphics.ctyme.com/gif/tip.gif" ALT="Sponsors" height="40" width="40"></a>
<br><a href="javascript:if(confirm('http://www.ctyme.com/sponsor.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/sponsor.htm'" tppabs="http://www.ctyme.com/sponsor.htm">Shopping</a>
</td><td width="65">
<a href="javascript:if(confirm('http://talk.ctyme.com/webx.cgi?13@@.ee6b2be \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://talk.ctyme.com/webx.cgi?13@@.ee6b2be'" tppabs="http://talk.ctyme.com/webx.cgi?13@@.ee6b2be">
<img src="comment.gif" tppabs="http://graphics.ctyme.com/gif/comment.gif" ALT="Forum" height="40" width="40"></a>
<br><a href="javascript:if(confirm('http://talk.ctyme.com/webx.cgi?13@@.ee6b2be \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://talk.ctyme.com/webx.cgi?13@@.ee6b2be'" tppabs="http://talk.ctyme.com/webx.cgi?13@@.ee6b2be">Forum</a>
</td><td width="65">
<a href="javascript:if(confirm('http://www.ctyme.com/mail.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/mail.htm'" tppabs="http://www.ctyme.com/mail.htm">
<img src="mail.gif" tppabs="http://graphics.ctyme.com/gif/mail.gif" ALT="email" height="40" width="40"></a>
<br><a href="javascript:if(confirm('http://www.ctyme.com/mail.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/mail.htm'" tppabs="http://www.ctyme.com/mail.htm">EMail</a>
</td><td width="65">
<a href="javascript:if(confirm('http://www.ctyme.com/map.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/map.htm'" tppabs="http://www.ctyme.com/map.htm">
<img src="toc.gif" tppabs="http://graphics.ctyme.com/gif/toc.gif" ALT="Index" height="40" width="40"></a>
<br><a href="javascript:if(confirm('http://www.ctyme.com/map.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/map.htm'" tppabs="http://www.ctyme.com/map.htm">Index</a>
</td><td width="65">
<a href="javascript:if(confirm('http://www.ctyme.com/ \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/'" tppabs="http://www.ctyme.com/">
<img src="home.gif" tppabs="http://graphics.ctyme.com/gif/home.gif" ALT="Home" height="40" width="40"></a>
<br><a href="javascript:if(confirm('http://www.ctyme.com/ \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/'" tppabs="http://www.ctyme.com/">Home</a>
</td><td width="90">
<center>
<FORM ACTION="https://secure.paypal.com/cgi-bin/webscr" tppabs="https://secure.paypal.com/cgi-bin/webscr" METHOD="POST" traget="_blank">
<INPUT TYPE="hidden" NAME="cmd" VALUE="_xclick">
<INPUT TYPE="hidden" NAME="business" VALUE="marc@perkel.com">
<INPUT TYPE="hidden" NAME="return" VALUE="http://www.perkel.com">
<INPUT TYPE="hidden" NAME="item_name" VALUE="Donation To Support this Site">
<INPUT TYPE="hidden" NAME="no_intl" VALUE="1">
<INPUT TYPE="image" SRC="x-click-but7.gif" tppabs="http://images.paypal.com/images/x-click-but7.gif" vspace=9
NAME="submit" ALT="Make payments with PayPal - it's fast, free and secure!">
</FORM>
</td></tr></table></td></tr></table><p>
<center>
<p>
<a href="javascript:if(confirm('http://www.ctyme.com/hosting/index.htm \n\nThis file was not retrieved by Teleport Pro, because it is addressed on a domain or path outside the boundaries set for its Starting Address. \n\nDo you want to open it from the server?'))window.location='http://www.ctyme.com/hosting/index.htm'" tppabs="http://www.ctyme.com/hosting/index.htm" target="_blank">
<img src="ctymehost.gif" tppabs="http://graphics.ctyme.com/gif/ctymehost.gif"
border=3 height=60 width=468></a>
<p>
<!-- Ad End --->
</center>
<FORM ACTION="http://service.bfast.com/bfast/click" target="_blank">
<INPUT TYPE="hidden" NAME="siteid" VALUE="30472466" >
<INPUT TYPE="hidden" NAME="bfpage" VALUE="horizontal">
<INPUT TYPE="hidden" NAME="bfmid" VALUE="27253343" >
<INPUT TYPE="hidden" NAME="num" VALUE="30">
<table bgcolor=white border=3><tr><td>
<table bgcolor=white border=0>
<tr><td>
<IMG SRC="serve-bfmid=27253343&siteid=30472466&bfpage=horizontal.gif" tppabs="http://service.bfast.com/bfast/serve?bfmid=27253343&siteid=30472466&bfpage=horizontal" BORDER="0" WIDTH="1" HEIGHT="1" align=right NOSAVE >
<center><b>Search the web with Google</b></center>
</td></tr><tr><td>
<TABLE cellpadding=0 cellspacing=5 bgcolor="#FFFFFF">
<tr><td bgcolor="#0000cc"><IMG SRC="cleardot.gif" tppabs="http://www.google.com/images/cleardot.gif" height=1 border="0" ALT="Google"></td></tr><tr><td>
<IMG SRC="affiliate_logo.gif" tppabs="http://www.google.com/affiliates/affiliate_logo.gif" border="0" ALT="Google" align="center">
<INPUT TYPE=text name=q size=30 maxlength=255 value="">
<INPUT type=submit name=sa VALUE="Go">
</td></tr>
<tr><td bgcolor="#0000cc"><IMG SRC="cleardot.gif" tppabs="http://www.google.com/images/cleardot.gif" height=1 border="0" ALT="Google"></td></tr></TABLE>
</td></tr></table>
</tr></td></table>
</FORM>
</center>
<p><img src="rbline.gif" tppabs="http://graphics.ctyme.com/gif/rbline.gif" width="100%" alt="------"><p>
<!-- Bottom Link End -->
</BODY>
</HTML>