linux - [Solved-5 Solutions] Are there any standard exit status codes in Linux ? - ubuntu - red hat - debian - linux server - linux pc
Linux - Problem :
Are there any standard exit status codes in Linux ?
Linux - Solution 1:
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <signal.h>
int main() {
int status;
pid_t child = fork();
if (child <= 0)
exit(42);
waitpid(child, &status, 0);
if (WIFEXITED(status))
printf("first child exited with %u\n", WEXITSTATUS(status));
/* prints: "first child exited with 42" */
child = fork();
if (child <= 0)
kill(getpid(), SIGSEGV);
waitpid(child, &status, 0);
if (WIFSIGNALED(status))
printf("second child died with %u\n", WTERMSIG(status));
/* prints: "second child died with 11" */
}click below button to copy the code. By - Linux tutorial - team
The shell only stores an 8-bit return code, but sets the high bit if the process was abnormally terminated.
$ sh -c 'exit 42'; echo $?
42
$ sh -c 'kill -SEGV $$'; echo $?
Segmentation fault
139
$ expr 139 - 128
11click below button to copy the code. By - Linux tutorial - team
If you're seeing anything other than this, then the program probably has a SIGSEGV signal handler which then calls exit normally, so it isn't actually getting killed by the signal.
Linux - Solution 2:
Part 1: Advanced Bash Scripting
- 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
Part 2: sysexits.h
The ABSG references sysexits.h.
On Linux:
$ find /usr -name sysexits.h
/usr/include/sysexits.h
$ 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 */click below button to copy the code. By - Linux tutorial - team
Linux - Solution 3:
- 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"
- 130 Script terminated by Control-C
- 255 Exit status out of range
- This is for bash. However, for other applications, there are different exit codes.
Linux - Solution 4:
From the OpenBSD:
- According to style(9), it is not good practice to call exit(3) with arbi- trary values to indicate a failure condition when ending a program.
- In- stead, 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
Linux - Solution 5:
- There are no standard exit codes, aside from 0 meaning success. Non-zero doesn't necessarily mean failure either.
- stdlib.h does define EXIT_FAILURE as 1 and EXIT_SUCCESS as 0, but that's about it.
- The 11 on segfault is interesting, as 11 is the signal number that the kernel uses to kill the process in the event of a segfault.
- There is likely some mechanism, either in the kernel or in the shell, that translates that into the exit code