[BusyBox] Re: busybox-cvs Digest, Vol 29, Issue 4

[Vladimir N. Oleynik]

Rainer,

> What actually is unecessary is that each and every program contains a
> virtually identical sequence of code to turn it into a background
> process, especially given that there is at least one program that
> always runs in the background, namely, init, and which already
> contains everything required to be a 'supervisor' process. For special
> tasks that should run in the background, a tool can be used to just
> start them that way (please note that the code below needs
> POSIXLY_CORRECT=1 in the environment, to work around serious GNU
> getopt braindamage, and that it contains some features that are specific
> to the enviroment it usually operates in).
> 
> -------------------------------
> /*
>   run a program in a background session
> */

Its strange applet and haven`t 'supervisor' features:
fork()+exec*() only, and have not wait and restart if damage.

> /*  functions */
> static int sys_die(char const *fnc, char const *sysc) __attribute__ ((noreturn));
> 
> static int sys_die(char const *fnc, char const *sysc)
> {
>     syslog(LOG_ERR, "%s: %s: %m(%d)", fnc, sysc, errno);
>     exit(1);
> }

Hmm. This compiled without warning: return for not returned function?

> static void remove_lock_params(void)
> {
>     char **e_run, **e_last;
> 
>     e_last = e_run = environ;
>     if (!*e_last) return;
>     while (e_last[1]) ++e_last;
>     
>     e_run = environ;
>     while (e_run < e_last)
> 	if (strncmp(*e_run, LOCK_PREFIX, LOCK_PREFIX_LEN) == 0) {
> 	    *e_run = *e_last;
> 	    *e_last-- = NULL;
> 	} else
> 	    ++e_run;
>     
>     if (strncmp(*e_run, LOCK_PREFIX, LOCK_PREFIX_LEN) == 0) *e_run = NULL;
> }

Hmm. Knotty.
May be simply (not tested):

static void remove_lock_params(void)
{
     char **e, **t;

     for (e = t = environ; t && *t; t++)
	if (strncmp(*t, LOCK_PREFIX, LOCK_PREFIX_LEN) != 0) {
	    *e = *t;
	    e++;	
	}
     if(e)
	*e = NULL;
}


--w
vodz