A (user specified) output file cannot be created.
Something was found in an unconfigured or misconfigured state.
The input data was incorrect in some way.
The input data was incorrect in some way.
This should only be used for user's data and not system files.
An error occurred while doing I/O on some file.
The host specified did not exist.
The host specified did not exist.
This is used in mail addresses or network requests.
An input file (not a system file) did not exist or was not readable.
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).
You did not have sufficient permission to perform the operation.
The user specified did not exist.
The user specified did not exist.
This might be used for mail addresses or remote logins.
An operating system error has been detected.
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.
Some system file does not exist, cannot be opened, or has some sort of error.
Some system file does not exist, cannot be opened, or has some sort of error.
E.g., there is a syntax error in /etc/passwd
or /var/run/utx.active
.
The command succeeded.
The remote system returned something that was **not possible** during a protocol exchange.
An internal software error has been detected.
An internal software error has been detected.
This should be limited to non-operating system related errors as possible.
Temporary failure, indicating something that is not really an error.
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.
A service is unavailable.
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.
The command was used incorrectly.
The command was used incorrectly.
E.g., it was used with the wrong number of arguments, a bad flag, a bad syntax in a parameter, or whatever.
A container of standardized exit codes.
These are based on the BSD standardized exit codes. Linux and SysV don't really have a OS-level standard, and many applications use different codes, but these are the most standardized codes that exist.