Re: md5sum and filenames containing \

[Steve Lilly]

Olivier Delhomme wrote:

> On Sun, 03 Apr 2005 23:34:00 +0100, Steve Lilly was saying :
>
>  
>
> > Dear GNU,
> >
> > I was testing one of my own scripts for robustness against exotic 
> > filenames containing "\" when I noticed a peculiar behaviour from the 
> > md5sum utility (version 5.2.1). To demonstrate:
> >
> > address@hidden test]$ touch test\\test
> > address@hidden test]$ ls
> > test\test
> > address@hidden test]$ md5sum *
> > \d41d8cd98f00b204e9800998ecf8427e  test\\test
> >
> > I have tried this with bash and tcsh. ls confirms the file has a single 
> > \ character. It appears (to me at least) that md5sum is escaping the \ 
> > to \\, but I'm baffled as to the extra \ at the beginning of the hash!
> >    
>
> Here I have coreutils 5.2.1, debian 3.1 unstable, bash 3.00.16(1)
> and I can not reproduce your problem. The hash value is correct and
> without the \ at the beginning.
>
> Please could you tell us which is your system and bash version ?
>
>  
>
> > Regards,
> > Steve Lilly
> >    
>
> Regards,
> Olivier Delhomme.
GNU bash, version 2.05b.0(1)-release (i386-redhat-linux-gnu)
Fedora Core release 2 (Tettnang)

On a little further investigation, I think I have found the culprit in 
md5sum.c:

230:
/* Ignore this line if it is too short.
  Each line must have at least `min_digest_line_length - 1' (or one 
more, if
  the first is a backslash) more characters to contain correct message 
digest
  information.  */
if (s_len - i < min_digest_line_length + (s[i] == '\\'))
 return 1;

if (s[i] == '\\')
 {
   ++i;
   escaped_filename = 1;
 }

693:
/* Output a leading backslash if the file name contains
  a newline or backslash.  */
if (strchr (file, '\n') || strchr (file, '\\'))
 putchar ('\\');

So it appears to be intended behaviour, though why I'm not sure...

Steve Lilly.