PATCH: POSIX exit codes (not quite Re: status codes on Dec OSF)

["Bart Schaefer" <schaefer@candle.brasslantern.com>]

On Jun 22, 10:01am, Andrej Borsenkow wrote:
} Subject: RE: status codes on Dec OSF
}
} > >From the dec 4.0F machine
} > % /opt/bcs/packages/zsh-4.0.1/bin/zsh -x foo
} > +foo:1> FOO=+foo:1> jfkljfs
} > foo:1: command not found: jfkljfs
} > +foo:1> FOO=
} > +foo:2> echo 0
} > 0
} 
} 
} Sigh, this is a bug :-(

It's a bug on a particular operating system, and one which Sven was not
able to reproduce.

I'm made suspicious by "/opt/bcs/" in the command name.  That smells of
"binary compatibility standard" to me -- which could mean that zsh was
not compiled for the operating system under which it is executing.

Apparently quoting from the POSIX standard, Andrej goes on:
 
} If there is a command name, execution will continue as described in Command
} Search and Execution . If there is no command name, but the command
} contained a command substitution, the command will complete with the exit
} status of the last command substitution performed. Otherwise, the command
} will complete with a zero exit status.
} 
} If a command is not found, the exit status will be 127. If the command name
} is found, but it is not an executable utility, the exit status will be 126.
} Applications that invoke utilities without using the shell should use these
} exit status values to report similar errors.

Zsh already conforms to the first paragraph (or at least attempts to); the
patch below deals with the second paragraph.  Sample output:

zagzig% foo=`stamp-h`
zsh: command not found: stamp-h
zagzig% echo $?
127
zagzig% foo=`./stamp-h`
zsh: permission denied: ./stamp-h
zagzig% echo $?        
126
zagzig% echo foo=`./stamp-h`
zsh: permission denied: ./stamp-h
foo=
zagzig% echo $?
0

Is there any possibility that anyone is relying explicitly upon (($? == 1))
as was formerly the case for both command-not-found and permission-denied?

--- zsh-forge/current/Src/exec.c	Wed Jun 20 08:57:01 2001
+++ zsh-4.0/Src/exec.c	Fri Jun 22 20:04:31 2001
@@ -502,7 +502,7 @@
 		(arg0[0] == '.' && (arg0 + 1 == s ||
 				    (arg0[1] == '.' && arg0 + 2 == s)))) {
 		zerr("%e: %s", arg0, errno);
-		_exit(1);
+		_exit(errno == EACCES ? 126 : 127);
 	    }
 	    break;
 	}
@@ -556,7 +556,7 @@
 	zerr("%e: %s", arg0, eno);
     else
 	zerr("command not found: %s", arg0, 0);
-    _exit(1);
+    _exit(eno == EACCES ? 126 : 127);
 }
 
 #define RET_IF_COM(X) { if (iscom(X)) return docopy ? dupstring(X) : arg0; }

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com

Zsh: http://www.zsh.org | PHPerl Project: http://phperl.sourceforge.net