Article: Q47692
Product(s): Microsoft C Compiler
Version(s): MS-DOS:5.1,6.0,6.00a,6.00ax,7.0; WINDOWS:1.0,1.5; WINDOWS NT:1.0,2.0,2.1,4.0,5.0
Operating System(s):
Keyword(s): kbCRT kbVC kbVC100 kbVC150 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600
Last Modified: 22-JUL-2001
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The information in this article applies to:
- The C Run-Time (CRT), included with:
- Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, 6.0ax
- Microsoft C/C++ for MS-DOS, version 7.0
- Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5
- Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 2.1, 4.0, 5.0, 6.0
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SUMMARY
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When an error occurs in some library routines, the errno variable is set to a
value that can be used to indicate the nature of the error. These error codes
are defined in the file ERRNO.H. The codes were originally set up for use with
UNIX to conform to errors occurring under that operating system. Because of
this, and the differences between the various operating systems, many of the
codes have no relevance to the MS-DOS and Windows NT environments.
To maintain compatibility with UNIX and XENIX, all the codes, whether meaningful
or not, are defined in ERRNO.H. However, in the description of the global
variable errno, the CRT documentation included with each of the above products
lists only those codes (and their meanings) applicable to the corresponding
operating system, either MS-DOS or Windows NT. To output the associated the
error messages of these codes, use the perror() function.
If a returned errno value is not one of the listed codes, it can be assumed that
the error code was generated incorrectly and is not indicative of the true
problem. The documentation for the specific function used denotes which errno
values, if any, may be set by an error in that function.
MORE INFORMATION
================
The following is a listing of all the errno values defined in ERRNO.H along with
brief descriptions of their meanings. Only the values marked with an asterisk
(*) are considered valid under MS-DOS. Those marked with a plus sign (+) are
considered valid under Windows NT.
For more information on the values not marked with an asterisk or a plus sign,
see a UNIX or XENIX system manual.
Value Define Description
----- ------ -----------
EPERM 1 Not owner
ENOENT 2 *+No such file or directory
ESRCH 3 No such process
EINTR 4 Interrupted system call
EIO 5 I/O error
ENXIO 6 No such device or address
E2BIG 7 *+Argument list too long
ENOEXEC 8 *+Exec format error
EBADF 9 *+Bad file number
ECHILD 10 +No spawned processes
EAGAIN 11 +No more processes; not enough memory;
maximum nesting level reached
ENOMEM 12 *+Not enough memory
EACCES 13 *+Permission denied
EFAULT 14 Bad address
ENOTBLK 15 Block device required
EBUSY 16 Mount device busy
EEXIST 17 *+File exists
EXDEV 18 *+Cross-device link
ENODEV 19 No such device
ENOTDIR 20 Not a directory
EISDIR 21 Is a directory
EINVAL 22 *+Invalid argument
ENFILE 23 File table overflow
EMFILE 24 *+Too many open files
ENOTTY 25 Not a teletype
ETXTBSY 26 Text file busy
EFBIG 27 File too large
ENOSPC 28 *+No space left on device
ESPIPE 29 Illegal seek
EROFS 30 Read-only file system
EMLINK 31 Too many links
EPIPE 32 Broken pipe
EDOM 33 *+Math argument
ERANGE 34 *+Result too large
EUCLEAN 35 File system needs cleaning
EDEADLK 36 +Resource deadlock would occur
EDEADLOCK 36 *Resource deadlock would occur
ENAMETOOLONG 38
ENOLCK 39
ENOSYS 40
ENOTEMPTY 41
EILSEQ 42
* Used under both MS-DOS
+ Used under Windows NT
NOTE: With Visual C++ 32-bit Edition, EDEADLK is the preferred manifest constant
for "resource deadlock." However, EDEADLOCK is supported for compatibility with
older MS-C versions.
For more information on errno and its possible values, please consult the Visual
C++ Book Online.
Additional query words:
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Keywords : kbCRT kbVC kbVC100 kbVC150 kbVC200 kbVC210 kbVC400 kbVC500 kbVC600
Technology : kbVCsearch kbAudDeveloper kbCRT
Version : MS-DOS:5.1,6.0,6.00a,6.00ax,7.0; WINDOWS:1.0,1.5; WINDOWS NT:1.0,2.0,2.1,4.0,5.0
Issue type : kbinfo
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