Add error checking for poorly-formed crossystem args

Add error checking for poorly-formed crossystem args

R=petkov@chromium.org
BUG=chromium-os:13322
TEST=manual

The following command lines should cause crossystem to fail with a
warning about a poorly formed parameter:
  crossystem ''
  crossystem '=cros_debug'
  crossystem '?cros_debug'

The following command line should warn that you can't use both = and ?:
  crossystem cros_debug?=0
(that is, it warns, not just compares with '=0')

The following should print 'UNEQUAL'
  crossystem cros_debug? || echo UNEQUAL
(because it's comparing cros_debug with an empty string)

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=f27583f

[petkov, 2011-03-21 22:42:30]

LGTM although I don't see where the foo?=0 warning is coming from?

http://codereview.chromium.org/6718012/diff/1/utility/crossystem_main.c
File utility/crossystem_main.c (right):

http://codereview.chromium.org/6718012/diff/1/utility/crossystem_main.c#newco...
utility/crossystem_main.c:232: if (!name || has_set == argv[i] || has_expect ==
argv[i]) {
is

if (!name || strlen(name) == 0)

a bit more readable?

then you wouldn't some of the other changes.

[Randall Spangler, 2011-03-21 22:47:51]

On 2011/03/21 22:42:30, petkov wrote:
> LGTM although I don't see where the foo?=0 warning is coming from?

if (has_set && has_expect)

> is
> 
> if (!name || strlen(name) == 0)
> 
> a bit more readable?
> 
> then you wouldn't some of the other changes.

strtok() ignores leading delimiter chars, so strtok("=foo", "=?") returns "foo"

(though in python, argv[i].split('=foo') does return ['', 'foo'])

[Randall Spangler, 2011-03-21 22:49:12]

On 2011/03/21 22:47:51, Randall Spangler wrote:
> On 2011/03/21 22:42:30, petkov wrote:
> > LGTM although I don't see where the foo?=0 warning is coming from?
> 
> if (has_set && has_expect)
> 
> > is
> > 
> > if (!name || strlen(name) == 0)
> > 
> > a bit more readable?
> > 
> > then you wouldn't some of the other changes.
> 
> strtok() ignores leading delimiter chars, so strtok("=foo", "=?") returns
"foo"
> 
> (though in python, argv[i].split('=foo') does return ['', 'foo'])

... I meant, '=foo'.split('=')

[petkov, 2011-03-21 23:00:53]

On 2011/03/21 22:47:51, Randall Spangler wrote:
> On 2011/03/21 22:42:30, petkov wrote:
> > LGTM although I don't see where the foo?=0 warning is coming from?
> 
> if (has_set && has_expect)
> 
> > is
> > 
> > if (!name || strlen(name) == 0)
> > 
> > a bit more readable?
> > 
> > then you wouldn't some of the other changes.
> 
> strtok() ignores leading delimiter chars, so strtok("=foo", "=?") returns
"foo"

ah -- ugly..

> 
> (though in python, argv[i].split('=foo') does return ['', 'foo'])