The Support Kit: Error Codes

Declared in: be/support/Errors.h

Error codes are returned by various functions to indicate the success or to describe the failure of a requested operation.

All Be error constants except for B_NO_ERROR are negative integers; any function that returns an error code can thus be lazily tested for success or failure by the following:

   if ( funcCall() < B_NO_ERROR )
      /* failure */
   else
      /* success */

All constants (except B_NO_ERROR and B_ERROR) are less than or equal to the value of the B_ERRORS_END constant. If you want to define your own negative-valued error codes, you should begin with the value (B_ERRORS_END + 1) and work your way toward 0.

POSIX Errors and sterror()

The BeOS supports the POSIX error code constants (these constants start with the letter "E", as in EBADF or ENOENT). A number of Be-defined constants aresynonyms for the POSIX constants; for example, the Be equivalent for ENOENT is B_ENTRY_NOT_FOUND.

Most of the General Error Codes, and all the File System Error Codes are covers for POSIX errors. The POSIX equivalents are listed where applicable.

The POSIX constants, and the Be synonyms, can be passed to the POSIX strerror() function. The function, which is defined in posix/string.h, returns a human-readable description of the error:

   char *strerror(int error_code)

General Error Codes

Code	POSIX	Description
B_NO_MEMORY	ENOMEM	There's not enough memory for the operation
B_IO_ERROR	EIO	A general input/output error occurred
B_PERMISSION_DENIED	EACCESS	Illegal access
B_BAD_INDEX		The index is out of range.
B_BAD_VALUE	EINVAL	An illegal value was passed to the function
B_MISMATCHED_VALUES		Conflicting values were passed to the function
B_BAD_TYPE		An illegal argument type was named or passed
B_NAME_NOT_FOUND		There's no match for the specified name.
B_NAME_IN_USE		The requested (unique) name is already used
B_BUSY	EBUSY	A device is busy, or a file is locked
B_NOT_ALLOWED	EPERM	Operation not allowed
B_NO_INIT		An object or structure isn't properly initialized
B_TIMED_OUT	ETIMEDOUT	Time expired before the operation was finished
B_INTERRUPTED	EINTR	A signal interrupted the operation
B_WOULD_BLOCK	EAGAIN/EWOULDBLOCK	But you don't want to
B_ERROR = -1		A convenient catchall for general errors
B_NO_ERROR = 0		Everything's OK
B_OK		Same as B_NO_ERROR

File System Error Codes

Code	POSIX	Description
B_FILE_ERROR	EBADF	A file error occurred
B_FILE_EXISTS	EEXIST	And you don't want to clobber it
B_ENTRY_NOT_FOUND	ENOENT	The requested entry doesn't exist
B_NAME_TOO_LONG	ENAMETOOLONG	Leaf or pathname too long
B_NO_MORE_FDS	EMFILE	No more file descriptors
B_NOT_A_DIRECTORY	ENOTDIR	When it should have been
B_IS_A_DIRECTORY	EISDIR	When it shouldn't be
B_DIRECTORY_NOT_EMPTY	ENOTEMPTY	Attempt to delete a non-empty directory
B_DEVICE_FULL	ENOSPC	Full disk
B_READ_ONLY_DEVICE	EROFS	Write request on a read-only file system
B_CROSS_DEVICE_LINK	EXDEV	Hard link across devices not allowed
B_LINK_LIMIT	ELOOP	Nested links too deep
B_BUSTED_PIPE	EPIPE	Pipe no longer functional.

Application Kit Error Codes

Code	Description
B_DUPLICATE_REPLY	A reply message has already been sent
B_BAD_REPLY	The reply message is inappropriate and can't be sent
B_BAD_HANDLER	The designated message handler isn't valid
B_MESSAGE_TO_SELF	A thread is trying to send a message to itself
B_ALREADY_RUNNING	The application can't be launched again
B_LAUNCH_FAILED	The attempt to launch the application failed
B_AMBIGUOUS_APP_LAUNCH	Odd things happening in app land
B_UNKOWN_MIME_TYPE	Application signature unknown
B_BAD_SCRIPT_SYNTAX	Script syntax malformed

Kernel Kit Error Codes

Code	Description
B_BAD_THREAD_ID	Specified thread identifier (thread_id) is invalid
B_BAD_THREAD_STATE	The thread is in the wrong state for the operation
B_NO_MORE_THREADS	All thread identifiers are currently taken
B_BAD_TEAM_ID	Specified team identifier (team_id) is invalid
B_NO_MORE_TEAMS	All team identifiers are currently taken
B_BAD_PORT_ID	Specified port identifier (port_id) is invalid
B_NO_MORE_PORTS	All port identifiers have been taken
B_BAD_SEM_ID	Semaphore identifier (sem_id) is invalid
B_NO_MORE_SEMS	All semaphores are currently taken
B_BAD_IMAGE_ID	Specified image identifier (image_id)is invalid
B_NOT_AN_EXECUTABLE	An executable image was expected
B_BAD_ADDRESS	Illegal address.

Media Kit Error Codes

Code	Description
B_STREAM_NOT_FOUND	The attempt to locate the stream failed
B_SERVER_NOT_FOUND	The attempt to locate the server failed
B_RESOURCE_NOT_FOUND	The attempt to locate the resource failed
B_RESOURCE_UNAVAILABLE	Permission to access the resource was denied
B_BAD_SUBSCRIBER	The BSubscriber is invalid.
B_SUBSCRIBER_NOT_ENTERED	The BSubscriber hasn't entered the stream
B_BUFFER_NOT_AVAILABLE	The attempt to acquire the buffer failed.

Mail Errors

Code	Description
B_MAIL_NO_DAEMON	mail_daemon not running
B_MAIL_UNKNOWN_USER	User unknown
B_MAIL_WRONG_PASSWORD	Password doesn't match user
B_MAIL_UNKNOWN_HOST	POP or SMTP host unrecognized
B_MAIL_ACCESS_ERROR	Couldn't access host
B_MAIL_UNKNOWN_FIELD	Unrecognized message field name
B_MAIL_NO_RECIPIENT	Return to sender, address unknown
B_MAIL_INVALID_MAIL	Invalid mail invalid mail invalid

Device Kit Errors

Code
B_DEV_INVALID_IOCTL
B_DEV_NO_MEMORY
B_DEV_BAD_DRIVE_NUM
B_DEV_NO_MEDIA
B_DEV_UNREADABLE
B_DEV_FORMAT_ERROR
B_DEV_TIMEOUT
B_DEV_RECALIBRATE_ERROR
B_DEV_SEEK_ERROR
B_DEV_ID_ERROR
B_DEV_READ_ERROR
B_DEV_WRITE_ERROR
B_DEV_NOT_READY
B_DEV_MEDIA_CHANGED

The Be Book, in lovely HTML, for the BeOS Preview Release.

Copyright © 1997 Be, Inc. All rights reserved.

Be is a registered trademark; BeOS, BeBox, BeWare, GeekPort, the Be logo, and the BeOS logo are trademarks of Be, Inc.

Last modified June 30, 1997.