Introduction to POSIX

The errno Variable

As described in in Chapter 1, "Introduction to the SAS/C Library," in SAS/C Library Reference, Volume 1, the external int variable errno contains the number of the most recent error or warning condition detected by the run-time library. To use this value, include the header file <errno.h> .

POSIX and USS Error Numbers

The <errno.h> header file contains definitions for the macro identifiers that name system error status conditions. When a SAS/C Library function sets an error status by assigning a nonzero valued to errno , the calling program can check for a particular value by using the name defined in <errno.h> .

The following USS related, POSIX defined errno values are defined in <errno.h> :

E2BIG argument list for exec function too large

EAGAIN resource temporarily unavailable

EBUSY resource busy (synonym for EINUSE )

ECHILD child process not found

EDEADLK resource deadlock avoided

EFAULT invalid argument address

EFBIG file too large

EINVAL invalid function argument (synonym for EARE )

EISDIR output file is a directory

ELOOP too many symbolic links in pathname (1003.1a)

EMFILE open file limit exceeded (synonym for ELIMIT )

EMLINK system limit on links exceeded

EMVSEXPIRE expired password (non-POSIX extension)

EMVSINITIAL error in establishing USS process (non-POSIX extension)

EMVSNOTUP USS kernel is not active (non-POSIX extension)

EMVSPASSWORD incorrect password (non-POSIX extension)

ENAMETOOLONG filename too long

ENDENT file or directory not found (synonym for ENFOUND )

ENFILE too many open files in system

ENODEV inappropriate use of device

ENOEXEC attempt to execute non-executable file

ENOLCK no HFS record locks were available

ENOSYS function not implemented by system

ENOTDIR pathname component not a directory

ENOTEMPTY directory not empty

ENOTTY file is not a terminal

ENXIO non-existent or inappropriate device

EPERM operation not permitted

EPIPE write to pipe without headers

EROFS file system mounted read only

ESPIPE seek to unseekable file (synonym for EUNSUPP )

ESRCH process not found

EXDEV link from one file system to another

GIO input/output error (synonym for EDEVICE )

Note: In addition to the values listed above, common SAS/C errno values are listed in Chapter 1, "Introduction to the SAS/C Library," in SAS/C Library Reference, Volume 1. Also refer to errno.h for socket-related errno values. For a complete listing of all errno values, see the SAS/C Compiler and Library Quick Reference Guide. [cautionend]

Also note that USS frequently uses a reason code to provide additional information about errors occuring in POSIX functions. See "System Macro Information" in Chapter 1 of SAS/C Library Reference, Volume 1 for information on accessing USS reason codes.

Internal Error Numbers

The following errno values represent USS internal errors. Contact IBM Technical Support if you receive one of these errors. These errno values are described in more detail in the manual, OpenEdition Assembler Callable Services.

EIBMCANCELLED

EIBMCONFLICT

EIBMSOCKINUSE

EIBMSOCKOUTOFRANGE

EMVSCATLG

EMVSCVAF

EMVSDYNALC

EMVSPFSFILE

EMVSPFSPERM

EMVSSAF2ERR

EMVSSAFEXTRERR

EOFFLOADBOXDOWN

EOFFLOADBOXERROR

EOFFLOADBOXRESTART

Consult The POSIX.1 Standard: A Programmer's Guide by Fred Zlotnick (1991, Benjamin/Cummings Publishing) or the POSIX standards for information on the POSIX errno values; consult IBM USS documentation for information on the EMVS- and EIBM- errno values.

Because the errno values resulting from POSIX functions are well organized and well-defined, the SAS/C Library does not diagnose many problems that can occur with these functions, even when it diagnoses similar problems occurring with OS/390 files. This eases porting programs from other open systems, since these systems do not, in general, have library diagnostics. In general, the SAS/C Library will issue diagnostics for failures of USS functionality only when (a) the failure is certainly the result of programmer error, or (b) the error is so esoteric that diagnosis is unlikely without a message.

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`E2BIG`	argument list for `exec` function too large
`EAGAIN`	resource temporarily unavailable
`EBUSY`	resource busy (synonym for `EINUSE` )
`ECHILD`	child process not found
`EDEADLK`	resource deadlock avoided
`EFAULT`	invalid argument address
`EFBIG`	file too large
`EINVAL`	invalid function argument (synonym for `EARE` )
`EISDIR`	output file is a directory
`ELOOP`	too many symbolic links in pathname (1003.1a)
`EMFILE`	open file limit exceeded (synonym for `ELIMIT` )
`EMLINK`	system limit on links exceeded
`EMVSEXPIRE`	expired password (non-POSIX extension)
`EMVSINITIAL`	error in establishing USS process (non-POSIX extension)
`EMVSNOTUP`	USS kernel is not active (non-POSIX extension)
`EMVSPASSWORD`	incorrect password (non-POSIX extension)
`ENAMETOOLONG`	filename too long
`ENDENT`	file or directory not found (synonym for `ENFOUND` )
`ENFILE`	too many open files in system
`ENODEV`	inappropriate use of device
`ENOEXEC`	attempt to execute non-executable file
`ENOLCK`	no HFS record locks were available
`ENOSYS`	function not implemented by system
`ENOTDIR`	pathname component not a directory
`ENOTEMPTY`	directory not empty
`ENOTTY`	file is not a terminal
`ENXIO`	non-existent or inappropriate device
`EPERM`	operation not permitted
`EPIPE`	write to pipe without headers
`EROFS`	file system mounted read only
`ESPIPE`	seek to unseekable file (synonym for `EUNSUPP` )
`ESRCH`	process not found
`EXDEV`	link from one file system to another
`GIO`	input/output error (synonym for `EDEVICE` )

	`EIBMCANCELLED`
	`EIBMCONFLICT`
	`EIBMSOCKINUSE`
	`EIBMSOCKOUTOFRANGE`
	`EMVSCATLG`
	`EMVSCVAF`
	`EMVSDYNALC`
	`EMVSPFSFILE`
	`EMVSPFSPERM`
	`EMVSSAF2ERR`
	`EMVSSAFEXTRERR`
	`EOFFLOADBOXDOWN`
	`EOFFLOADBOXERROR`
	`EOFFLOADBOXRESTART`