sysexits.h

Section: Misc. Reference Manual Pages (3head)
Updated: 2022-12-15
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NAME

sysexits.h - exit codes for programs

LIBRARY

Standard C library (libc)

SYNOPSIS

#include <sysexits.h>

#define EX_OK	0	/*	successful termination */
#define EX__BASE	64	/*	base value for error messages */
#define EX_USAGE	64	/*	command line usage error */
#define EX_DATAERR	65	/*	data format error */
#define EX_NOINPUT	66	/*	cannot open input */
#define EX_NOUSER	67	/*	addressee unknown */
#define EX_NOHOST	68	/*	host name unknown */
#define EX_UNAVAILABLE	69	/*	service unavailable */
#define EX_SOFTWARE	70	/*	internal software error */
#define EX_OSERR	71	/*	system error (e.g., can't fork) */
#define EX_OSFILE	72	/*	critical OS file missing */
#define EX_CANTCREAT	73	/*	can't create (user) output file */
#define EX_IOERR	74	/*	input/output error */
#define EX_TEMPFAIL	75	/*	temp failure; user is invited to retry */
#define EX_PROTOCOL	76	/*	remote error in protocol */
#define EX_NOPERM	77	/*	permission denied */
#define EX_CONFIG	78	/*	configuration error */
#define EX__MAX	...	/*	maximum listed value */

DESCRIPTION

A few programs exit with the following error codes.

The successful exit is always indicated by a status of 0, or EX_OK (equivalent to EXIT_SUCCESS from <stdlib.h>). Error numbers begin at EX__BASE to reduce the possibility of clashing with other exit statuses that random programs may already return. The meaning of the code is approximately as follows:

EX_USAGE: The command was used incorrectly, e.g., with the wrong number of arguments, a bad flag, bad syntax in a parameter, or whatever.
EX_DATAERR: The input data was incorrect in some way. This should only be used for user's data and not system files.
EX_NOINPUT: An input file (not a system file) did not exist or was not readable. This could also include errors like "No message" to a mailer (if it cared to catch it).
EX_NOUSER: The user specified did not exist. This might be used for mail addresses or remote logins.
EX_NOHOST: The host specified did not exist. This is used in mail addresses or network requests.
EX_UNAVAILABLE: A service is unavailable. This can occur if a support program or file does not exist. This can also be used as a catch-all message when something you wanted to do doesn't work, but you don't know why.
EX_SOFTWARE: An internal software error has been detected. This should be limited to non-operating system related errors if possible.
EX_OSERR: An operating system error has been detected. This is intended to be used for such things as "cannot fork", "cannot create pipe", or the like. It includes things like getuid(2) returning a user that does not exist in the passwd(5) file.
EX_OSFILE: Some system file (e.g., /etc/passwd, /etc/utmp, etc.) does not exist, cannot be opened, or has some sort of error (e.g., syntax error).
EX_CANTCREAT: A (user specified) output file cannot be created.
EX_IOERR: An error occurred while doing I/O on some file.
EX_TEMPFAIL: Temporary failure, indicating something that is not really an error. For example that a mailer could not create a connection, and the request should be reattempted later.
EX_PROTOCOL: The remote system returned something that was "not possible" during a protocol exchange.
EX_OSFILE: You did not have sufficient permission to perform the operation. This is not intended for file system problems, which should use EX_NOINPUT or EX_CANTCREAT, but rather for higher level permissions.
EX_CONFIG: Something was found in an unconfigured or misconfigured state.

The numerical values corresponding to the symbolical ones are given in parenthesis for easy reference.

STANDARDS

Not in POSIX.1. Present on the BSDs. The <sysexits.h> file appeared in 4.0BSD for use by the deliverymail utility, later renamed to sendmail(8).

BUGS

The choice of an appropriate exit value is often ambiguous.

This document was created by man2html, using the manual pages.
Time: 16:41:42 GMT, May 18, 2024