SYSEXITS(3)

SYSEXITS(3) | Library Functions Manual | SYSEXITS(3)

# NAME

`sysexits` —
preferable exit codes for programs

# SYNOPSIS

`#include <sysexits.h>`

# DESCRIPTION

It is not a good practice to call exit(3) with arbitrary values to indicate a failure condition when ending a program. In addition to the two standard constants in `<stdlib.h>`, `EXIT_SUCCESS` and `EXIT_FAILURE`, the header `<sysexits.h>` defines few exit codes that can be used as a parameter to the exit(3) function. By using these constants 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), stdlib(3)

# HISTORY

The `<sysexits.h>` header appeared somewhere after 4.3BSD. The manual page for it appeared in NetBSD 4.0.

# AUTHORS

This manual page was written by Jörg Wunsch after the comments in `<sysexits.h>`.

# BUGS

The choice of an appropriate exit value is often ambiguous.

March 25, 2010 | NetBSD 9.0