NAME
sysexits
- preferable exit codes for programs
SYNOPSIS
DESCRIPTION
It is not a good practice to call
exit(3)
with arbitrary values to indicate a failure condition when ending
a program.
Instead, the pre-defined exit codes from
sysexits
should be used, so the caller of the process can get a rough
estimation about the failure class without looking up the source code.
The successful exit is always indicated by a status of 0, or
EX_OK
.
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 codes is
approximately as follows:
EX_USAGE (
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.
EX_DATAERR (
65)
-
The input data was incorrect in some way.
This should only be used
for user's data and not system files.
EX_NOINPUT (
66)
-
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 (
67)
-
The user specified did not exist.
This might be used for mail
addresses or remote logins.
EX_NOHOST (
68)
-
The host specified did not exist.
This is used in mail addresses or
network requests.
EX_UNAVAILABLE (
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.
EX_SOFTWARE (
70)
-
An internal software error has been detected.
This should be limited
to non-operating system related errors as possible.
EX_OSERR (
71)
-
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 returning a user that
does not exist in the passwd file.
EX_OSFILE (
72)
-
Some system file (e.g.,
/etc/passwd
,
/var/run/utmp
,
etc.) does not exist, cannot be opened, or has some sort of error
(e.g., syntax error).
EX_CANTCREAT (
73)
-
A (user specified) output file cannot be created.
EX_IOERR (
74)
-
An error occurred while doing I/O on some file.
EX_TEMPFAIL (
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.
EX_PROTOCOL (
76)
-
The remote system returned something that was
``not possible''
during a protocol exchange.
EX_NOPERM (
77)
-
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 (
78)
-
Something was found in an unconfigured or misconfigured state.
The numerical values corresponding to the symbolical ones are given in
parenthesis for easy reference.
SEE ALSO
err(3),
exit(3)
HISTORY
The
sysexits
file appeared somewhere after
4.3BSD.
The
sysexits
man page appeared in
NetBSD4.0.
AUTHORS
This manual page was written by
Jörg Wunsch
after the comments in
BUGS
The choice of an appropriate exit value is often ambiguous.