As in sysexits.h, but in a (sometimes) more accessible place. Formatted painlessly in Vim
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:
| Exit Code | Description |
|---|---|
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 catch-all 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 state. |