[RndTbl] (Simple?) Perl question
Gilbert E. Detillieux
gedetil at cs.umanitoba.ca
Mon Dec 12 14:04:03 CST 2016
That may actually be command-specific. I don't remember details, but I
have come across some Windows programs that didn't like the "/" being
used where they wanted to see "\" instead. I guess you could try it and
see, but there's no guarantee it will always work that way, either...
Gilbert
On 12/12/2016 1:57 PM, Kevin McGregor wrote:
> Ugh. Even under Windows, doesn't
>
> $cmd = "./psexec.exe //" . $server_name
>
> work the same? Is there any need to use backslashes here?
>
> On Mon, Dec 12, 2016 at 1:53 PM, Gilbert E. Detillieux
> <gedetil at cs.umanitoba.ca <mailto:gedetil at cs.umanitoba.ca>> wrote:
>
> Yup, makes sense now...
>
> After this line...
>
> $cmd = "./psexec.exe \\\\\\\\" . $server_name
>
> ... the cmd variable will contain "./psexec.exe \\\\server" (4
> backslashes. On running this line...
>
> my $output = `$cmd`
>
> ... the shell will see "./psexec.exe \\\\server", and the command
> will see (after shell quote processing) argv[1] set to "\\server".
>
> Each level of "\" escape processing requires that you double the
> number of "\" characters entered to get one through. If you want to
> end up with 2, after 2 levels, you need 8.
>
> Gilbert
>
> On 12/12/2016 1:43 PM, Kevin McGregor wrote:
>
> I should add that this gets run immediately after via
>
> my $output = `$cmd`
>
> if that makes any difference.
>
> On Mon, Dec 12, 2016 at 1:40 PM, Kevin McGregor
> <kevin.a.mcgregor at gmail.com <mailto:kevin.a.mcgregor at gmail.com>
> <mailto:kevin.a.mcgregor at gmail.com
> <mailto:kevin.a.mcgregor at gmail.com>>> wrote:
>
> I'm trying to decipher some Perl code which runs on a Windows
> server, and I ran into this:
>
> $cmd = "./psexec.exe \\\\\\\\" . $server_name
>
> I think the idea is to end up with
>
> ./psexec.exe \\server
>
> but WTF eight backslashes? Does that make any sense? If so, can
> someone ELI5?
>
> Kevin
--
Gilbert E. Detillieux E-mail: <gedetil at cs.umanitoba.ca>
Dept. of Computer Science Web: http://www.cs.umanitoba.ca/~gedetil/
University of Manitoba Phone: (204)474-8161
Winnipeg MB CANADA R3T 2N2 Fax: (204)474-7609
More information about the Roundtable
mailing list