On Wed, Mar 26, 2008 at 8:43 PM, Francisco J Ballesteros <[EMAIL PROTECTED]>
wrote:
> but
> echo -n '-n
> '
> is a hack.
yes
so is any of the other solutions, each with its own constraints.
> with a different implementation it might as well
> complaint that '
> ' is an invalid flag.
no. This breaks unnecesarily:
echo -a
-a
which is useful.
The kind of change I was suggesting was minimal. Just solved the problem
did not break anything else. The only thing it could have potentialy
break was
echo --
which before wrote
--
and now writes only the newline.
This could be easily solved by rewriting it as
echo -- --
and I haven't seen any instance of this in /rc/bin (I looked even
if it was not very carefully).
The benefits of the change are easy to see. If you write
echo -- anything
you know the anything is now being echoed, whatever that is.
>
> And in any case, the "do the same thing the same way
> all the times" argument suggests that -- should terminate
> option processing. doesn't it?
>
Yes, it is probably true that another "if" to ignore -- after the -n could
be added. I wrote it just as an example of how little change would be
needed. The complete change to do it "right" would be again:
(written as an example, untried and not being overly careful)
#include <u.h>
#include <libc.h>
void
main(int argc, char *argv[])
{
int nflag, argi;
int i, len;
char *buf, *p;
nflag = 0;
argi = 0;
if(argc > 1)
if(strcmp(argv[1], "--") == 0)
argi++;
else if(strcmp(argv[1], "-n") == 0){
nflag++;
argi++;
if(argc > 2 && strcmp(argv[2], "--") == 0)
argi++;
}
len = 1;
for(i = 1+argi; i < argc; i++)
len += strlen(argv[i])+1;
buf = malloc(len);
if(buf == 0)
exits("no memory");
p = buf;
for(i = 1+argi; i < argc; i++){
strcpy(p, argv[i]);
p += strlen(p);
if(i < argc-1)
*p++ = ' ';
}
if(!nflag)
*p++ = '\n';
if(write(1, buf, p-buf) < 0)
fprint(2, "echo: write error: %r\n");
exits((char *)0);
}
--
- curiosity sKilled the cat
