Exit Codes

Part 1: Advanced Bash Scripting Guide

1: Catchall for general errors

2: Misuse of shell builtins (according to Bash documentation)

126: Command invoked cannot execute

127: "command not found"

128: Invalid argument to exit

128+n: Fatal error signal "n"

255: Exit status out of range (exit takes only integer args in the range 0 - 255)

Part 2: sysexits.h

python https://docs.python.org/2/library/os.html#process-management

$ cat /usr/include/sysexits.h

/*
* Copyright (c) 1987, 1993
*  The Regents of the University of California.  All rights reserved.

(A whole bunch of text left out.)

#define EX_OK           0       /* successful termination */
#define EX__BASE        64      /* base value for error messages */
#define EX_USAGE        64      /* command line usage error */
#define EX_DATAERR      65      /* data format error */
#define EX_NOINPUT      66      /* cannot open input */
#define EX_NOUSER       67      /* addressee unknown */
#define EX_NOHOST       68      /* host name unknown */
#define EX_UNAVAILABLE  69      /* service unavailable */
#define EX_SOFTWARE     70      /* internal software error */
#define EX_OSERR        71      /* system error (e.g., can't fork) */
#define EX_OSFILE       72      /* critical OS file missing */
#define EX_CANTCREAT    73      /* can't create (user) output file */
#define EX_IOERR        74      /* input/output error */
#define EX_TEMPFAIL     75      /* temp failure; user is invited to retry */
#define EX_PROTOCOL     76      /* remote error in protocol */
#define EX_NOPERM       77      /* permission denied */
#define EX_CONFIG       78      /* configuration error */

#define EX__MAX 78      /* maximum listed value */