zfs-install doesn't work

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Build zfs xcode project (Debug) 
2. run sh -x support/zfs-install

What is the expected output?
sudo cp ...

What do you see instead?
exit 1

What version of the product are you using?
git tip [70194d2c84b9fea26551411c671792768b7bca58]

On what operating system?
10.6.4 x64

Original issue reported on code.google.com by timel...@gmail.com on 10 Nov 2010 at 1:42

Attachments:

• 0001-Fix-zfs-install-script-to-install-when-directory-is-.patch

[GoogleCodeExporter]

How can I recreate the bug? It's not clear that the patch does anything 
different; if the directory exists then [ -d dir ] will be true (and thus not 
do the exit).

Is this a case of using a different shell instead of bash?

Original comment by alex.ble...@gmail.com on 25 Nov 2010 at 7:31

[GoogleCodeExporter]

> how can I recreate the bug?
steps 1+2 let you recreate the problem.

> it's not clear...
the problem is that the code doesn't do what you think it will do when the 
directory *does* exist.

> Is this a case of using a different shell instead of bash?
Nope, I'm using bash. the shell script is just broken.

I spoke to a couple of people about this and determined that people don't 
really understand the subtle pitfalls of shell scripting.

Here's the technical explanation of the relevant operations from BASH(1):
   Lists
       A  list  is a sequence of one or more pipelines separated by one of the operators ;, &,
       &&, or ||, and optionally terminated by one of ;, &, or <newline>.

       Of these list operators, && and || have equal precedence, followed by ;  and  &,  which
       have equal precedence.
...
   Compound Commands
       A compound command is one of the following:
...
       { list; }
              list is simply executed in the current shell environment.

The key is that the order of operations is such that ; causes the stuff before 
it to be evaluated completely, and then the stuff after it is executed 
independently.
------

As that's unlikely to be helpful, I was suggested to explain the current code
> [ -d build/${CONFIGURATION} ] || echo build/${CONFIGURATION} not found; exit 1
> sudo cp -r build/${CONFIGURATION}/zfs.kext /System/Library/Extensions

... as if it were C instead of Shell:

bool test_dir()  {
  return is_dir("build/configuration");
}

void not_found() {
  printf("build/configuration not found\n");
}

void setup() {
  system("sudo cp ...");
}

int main(void) {
if (test_dir()) not_found(); exit 1;
setup();
return 0;
}

indented for clarity:

int main(void) {
    if (test_dir())
        not_found();
    exit 1;
    setup();
    return 0;
}

This obviously wouldn't be the C that you'd want to write....

In C, you could do this:

if (test_dir()) { not_found(); exit 1; }
setup();

which is equivalent to:
if (test_dir()) {
    not_found();
    exit 1;
}
setup();

So, there are two ways to fix the current code:
> [ -d build/${CONFIGURATION} ] || { echo build/${CONFIGURATION} not found; 
exit 1 }
> sudo cp -r build/${CONFIGURATION}/zfs.kext /System/Library/Extensions

or the attachment form. For people who are unfamiliar w/ shell scripting, I 
think that using if ; then ; fi is probably clearer than using {}s. The 
argument against using {} is that it isn't portable. It doesn't work on (t)csh 
or dash.

Original comment by timel...@gmail.com on 25 Nov 2010 at 9:49

[GoogleCodeExporter]

OK, gotcha. My bad.

Original comment by alex.ble...@gmail.com on 9 Dec 2010 at 2:18

• Changed state: Accepted

[GoogleCodeExporter]

Fixed in 

https://github.com/alblue/mac-zfs/commit/653b45b6b670bc9a179936017e3c7ca655e9c82
b

Will leave this as fixed until this becomes part of an installed build, which 
the 'untested' branch currently is not.

Original comment by alex.ble...@gmail.com on 11 Dec 2010 at 2:18

• Changed state: Fixed