1.0.0	Jan 10, 2023

Apache-2.0

16KB
170 lines

Semantic Exit Codes

os.Exit(exit.Forbidden) // The user isn't permitted to perform this action
os.Exit(exit.Unavailable) // An API this program consumes isn't available

use semantic_exit::{exit, Code};

exit(Code::Forbidden);
exit(Code::Unavailable);

Conventionally, exiting a program with zero indicates success while nonzero indicates failure.

os.Exit(0) // success
os.Exit(1) // failure

But the system call exit accepts values between 0 and 255, leaving 254 different ways of expressing failure.

This library's goals are to define exit codes that are:

It defines codes in two unreserved ranges: 80-99 for user errors and 100-119 for software or system errors.

Exit Code	Name	Meaning
0	`OK`	The program exited successfully.
1	`NotOK`	The program exited unsuccessfully but gives no extra context as to what the failure was.
80	`UsageError`	The program exited unsuccessfully because it was was used incorrectly. (e.g. a required argument was omitted or an invalid value was supplied for a flag.)
81	`UnknownSubcommand`	The program exited unsuccessfully because an unrecognized subcommand was invoked. (Used by CLI multi-tools.)
82	`RequirementNotMet`	The program exited unsuccessfully because a prerequisite of it wasn't met.
83	`Forbidden`	The program exited unsuccessfully because the user isn't authorized to perform the requested action.
84	`MovedPermanently`	The program exited unsuccessfully because it has been migrated to a new location.
100	`InternalError`	The program exited unsuccessfully because of a problem in its own code. (Used instead of 1 when the problem is known to be with the program's code or dependencies.)
101	`Unavailable`	The program exited unsuccessfully because a service it depends on was not available. (e.g. A local daemon or remote service did not respond, a connection was closed unexpectedly, an HTTP service responded with 503.)

Values above 128 are reserved for signals. (When a program is terminated with a signal, its exit code is 128 + the signal's numeric value. When you terminate a program with Ctrl C, for example, you send it the signal SIGINT — whose value is 2 — and the program exits with 130.)
Bash reserves 2, 126, and 127.
sysexits.h defines 64-78. The sysexits.h codes were originally defined for sendmail but have been used many places since. (Compare Semantic Exit Codes to sysexits.h codes)

~1.5MB
~40K SLoC