sysexits -- preferable exit codes for programs
According to style(9), 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
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
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 doesn't work, but you don't 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
The numerical values corresponding to the symbolical ones are given in
parenthesis for easy reference.
The sysexits file appeared somewhere after 4.3BSD.
This man page has been written by Jorg Wunsch after the comments in
The choice of an appropriate exit value is often ambiguous.
FreeBSD 5.2.1 March 31, 1996 FreeBSD 5.2.1 [ Back ]