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.Dd January 21, 2010
.Dt SYSEXITS 3
.Os
.Sh NAME
.Nm sysexits
.Nd preferable exit codes for programs
.Sh SYNOPSIS
.In sysexits.h
.Sh DESCRIPTION
According to
.Xr style 9 ,
it is not a good practice to call
.Xr exit 3
with arbitrary values to indicate a failure condition when ending
a program.
Instead, the pre-defined exit codes from
.Nm
should be used, so the caller of the process can get a rough
estimation about the failure class without looking up the source code.
.Pp
The successful exit is always indicated by a status of 0, or
.Sy EX_OK .
Error numbers begin at
.Sy EX__BASE
to reduce the possibility of clashing with other exit statuses that
random programs may already return.
The meaning of the codes is
approximately as follows:
.Bl -tag -width "EX_UNAVAILABLEXX(XX)"
.It Sy EX_USAGE Pq 64
The command was used incorrectly, e.g., with the wrong number of
arguments, a bad flag, a bad syntax in a parameter, or whatever.
.It Sy EX_DATAERR Pq 65
The input data was incorrect in some way.
This should only be used
for user's data and not system files.
.It Sy EX_NOINPUT Pq 66
An input file (not a system file) did not exist or was not readable.
This could also include errors like
.Dq \&No message
to a mailer (if it cared to catch it).
.It Sy EX_NOUSER Pq 67
The user specified did not exist.
This might be used for mail
addresses or remote logins.
.It Sy EX_NOHOST Pq 68
The host specified did not exist.
This is used in mail addresses or
network requests.
.It Sy EX_UNAVAILABLE Pq 69
A service is unavailable.
This can occur if a support program or file
does not exist.
This can also be used as a catchall message when
something you wanted to do does not work, but you do not know why.
.It Sy EX_SOFTWARE Pq 70
An internal software error has been detected.
This should be limited
to non-operating system related errors as possible.
.It Sy EX_OSERR Pq 71
An operating system error has been detected.
This is intended to be
used for such things as
.Dq cannot fork ,
.Dq cannot create pipe ,
or the like.
It includes things like getuid returning a user that
does not exist in the passwd file.
.It Sy EX_OSFILE Pq 72
Some system file (e.g.,
.Pa /etc/passwd ,
.Pa /var/run/utx.active ,
etc.) does not exist, cannot be opened, or has some sort of error
(e.g., syntax error).
.It Sy EX_CANTCREAT Pq 73
A (user specified) output file cannot be created.
.It Sy EX_IOERR Pq 74
An error occurred while doing I/O on some file.
.It Sy EX_TEMPFAIL Pq 75
Temporary failure, indicating something that is not really an error.
In sendmail, this means that a mailer (e.g.) could not create a
connection, and the request should be reattempted later.
.It Sy EX_PROTOCOL Pq 76
The remote system returned something that was
.Dq not possible
during a protocol exchange.
.It Sy EX_NOPERM Pq 77
You did not have sufficient permission to perform the operation.
This
is not intended for file system problems, which should use
.Sy EX_NOINPUT
or
.Sy EX_CANTCREAT ,
but rather for higher level permissions.
.It Sy EX_CONFIG Pq 78
Something was found in an unconfigured or misconfigured state.
.El
.Pp
The numerical values corresponding to the symbolical ones are given in
parenthesis for easy reference.
.Sh SEE ALSO
.Xr err 3 ,
.Xr exit 3 ,
.Xr style 9
.Sh HISTORY
The
.Nm
file appeared somewhere after
.Bx 4.3 .
.Sh AUTHORS
This manual page was written by
.An J\(:org Wunsch
after the comments in
.In sysexits.h .
.Sh BUGS
The choice of an appropriate exit value is often ambiguous.