i.e. BASH feeds that string into cat unmolested. Also check this:
Code:
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
int main(void)
{
int fd=open("///etc///passwd", O_RDONLY);
printf("fd=%d\n", fd);
if(fd >= 0) close(fd);
return(0);
}
open() itself swallows the extra slashes.
Of course, this is on a linux system. Let's try OSX, which at heart is still BSD:
Code:
# OSX defaults to bash
$ mkdir -p path/to/this
$ ls -l path/to/this
$ ls -l path///to///this
# ...but he's got lots of shells installed.
$ exec ksh
$ ls -l path/to/this
$ ls -l path///to///this
$ exec csh
% ls -l path/to/this
% ls -l path///to///this
% exec zsh
% ls -l path/to/this
% ls -l path///to///this
%
We can even do this:
Code:
> dir "c:/"
Volume in drive C has no label.
Volume Serial Number is 503A-5695
Directory of c:\
....
> dir "c://////////////////////////////////////"
Volume in drive C has no label.
Volume Serial Number is 503A-5695
Directory of c:\
....
> dir "c:\"
Volume in drive C has no label.
Volume Serial Number is 503A-5695
Directory of c:\
....
> dir "c:\\\\\\"
The filename, directory name, or volume label syntax is incorrect.
>
So even Windows CMD of all things swallows multiple slashes happily when processing UNIX-style paths because Microsoft is such a stickler for cross-platform compatibility. But not when processing normal paths, oddly.
Three operating systems, five shells -- this is not a "BASH-ism". I suspect this behavior is actually more common than rejecting them just because it's so easy to get extra slashes in things when scripting. Has anyone observed Solaris, HP-UX, AIX etc. rejecting them?
Last edited by Corona688; 12-02-2010 at 02:17 PM..
Solaris definitely and AIX, HP-UX, most if not all other Unix certainly ignore these extra slashes. Doing otherwise would be a bug as the Unix specification states "non-leading sequences of two or more slashes are treated as a single slash".
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