Re: Converting double slashes - C# Discussion Boards

steve_dunne27-Jul-07 2:52

steve_dunne

27-Jul-07 2:52

Or from within the stored procedure you can use something like this:

declare @test as nvarchar(40)
set @test = 'C:\\test\\rubbish\\file.asp'
select replace(@test, '\\', '\')

Guffa27-Jul-07 2:59

27-Jul-07 2:59

That will not do anything at all, as the string doesn't contain any double backslashes.

---
single minded; short sighted; long gone;

Guffa27-Jul-07 3:01

27-Jul-07 3:01

Martin# wrote:
filename.Replace("\\","\");

That won't even compile. What you intended to write was:

filename.Replace("\\\\","\\");

or

filename.Replace(@"\\",@"\");

However, that will not do anything at all, as the string doesn't contain any double backslashes.

---
single minded; short sighted; long gone;

Martin#27-Jul-07 3:05

Martin#

27-Jul-07 3:05

Sure!

All the best,

Martin

leppie27-Jul-07 3:05

leppie

27-Jul-07 3:05

LOL, that wont compile Smile | :)

Guffa27-Jul-07 2:54

27-Jul-07 2:54

Mark06 wrote:
sp_UpdateLogFile

Don't put "sp_" in the name of your stored procedure. "sp_" stands for "system procedure", and they are handled differently from normal stored procedures.

Mark06 wrote:
sql doesnt accept the \\ directory seperators

First of all, your string doesn't contain any double backslashes. The backslash is the escape character in string literals in C#. When you put double backslashes in a string literal, the string will contain a single backslash.

Second, the database has no problems with backslashes in string literals. In MS SQL the apostrophe is the escape character, the backslash has no special meaning at all.

What has made you come to the conclusion that the database would have any problem with double backslashes, especially as your string doesn't even contain any?

---
single minded; short sighted; long gone;

Mike Dimmick27-Jul-07 3:01

27-Jul-07 3:01

Guffa wrote:
Don't put "sp_" in the name of your stored procedure. "sp_" stands for "system procedure", and they are handled differently from normal stored procedures.

Specifically, SQL Server looks in the master database first, before looking in the database you're actually trying to use. This extra lookup doesn't cost a lot of time, but could break your application if Microsoft, or someone else, add a procedure with that name to the master database at a later date.

Stability. What an interesting concept. -- Chris Maunder

Mike Dimmick27-Jul-07 2:59

27-Jul-07 2:59

The backslash is an escape character within a string literal in C-based languages (C, C++, C#, Java), used to include non-printable characters within a string (for example, the newline character U+000A[^] is represented as '\n'). For that reason, to get an actual backslash in the string, you have to double it. This is processed by the compiler - in the compiled file, only a single backslash appears. Therefore you don't need to do anything to remove them at runtime - the compiler has already done it.

C# also supports @-quoted strings where the backslash is a literal backslash, not an escape character. The only escape available for this type of literal is "", which indicates that a single " character should be included in the string.

Stability. What an interesting concept. -- Chris Maunder

Mark0627-Jul-07 2:59

Mark06

27-Jul-07 2:59

appologies, I was trying to keep it simple.
I'm actually calling the stored proc 'sp_attach_db'
and I've tried command.CommandText.Replace("\\",@"\");
but it didnt do anything to the commandtext value.

Nouman Bhatti27-Jul-07 4:21

Nouman Bhatti

27-Jul-07 4:21

ms-help://MS.MSDNQTR.v80.en/MS.MSDN.v80/MS.NETDEVFX.v20.en/cpref2/html/M_System_String_Replace_1_d460c748.htm

use filename.replace("\\","\")

Mike Dimmick27-Jul-07 3:02

27-Jul-07 3:02

That's not surprising, both literals end up as a single backslash.

I suggest you post the actual problem you're encountering on the SQL/ADO/ADO.NET forum.

Stability. What an interesting concept. -- Chris Maunder

Mark0627-Jul-07 3:06

Mark06

27-Jul-07 3:06

but this isnt an sql problem.
the problem is, c# setting a commandtext to "sp_attach_db N'c:\\temp\\logfile.txt'" when it should be "sp_attach_db N'c:\temp\logfile.txt'"

the actual sql command is irrelevant. its the double slashes thats the issue.

Guffa27-Jul-07 3:12

27-Jul-07 3:12

Mark06 wrote:
the problem is, c# setting a commandtext to "sp_attach_db N'c:\\temp\\logfile.txt'" when it should be "sp_attach_db N'c:\temp\logfile.txt'"

It doesn't.

Why do you think that it would?

---
single minded; short sighted; long gone;

Mike Dimmick27-Jul-07 3:14

27-Jul-07 3:14

Damn debugger watch window (and tooltips) shows it as doubled.

Stability. What an interesting concept. -- Chris Maunder

Mark0627-Jul-07 3:31

Mark06

27-Jul-07 3:31

Yup, that'll be it!! Mad | :mad:

Mike Dimmick27-Jul-07 3:13

27-Jul-07 3:13

Visual Studio shows escapes in the C# debugger watch window and tooltips. I think that's a stupid idea, but there you are: that's what it does.

If you output the string to the console (Console.WriteLine) you will see that the backslashes are not doubled. If you're having trouble attaching the database, please ask on the other forum (including all error messages) - this is not the problem.

Stability. What an interesting concept. -- Chris Maunder

Luc Pattyn27-Jul-07 10:42

Luc Pattyn

27-Jul-07 10:42

Never, never apply Console.WriteLine on a suspicious variable.
You might find the cause of a problem...

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Guffa27-Jul-07 3:10

27-Jul-07 3:10

Mark06 wrote:
I've tried command.CommandText.Replace("\\",@"\");
but it didnt do anything to the commandtext value.

Of course not. You are replacing each single backslash with a single backslash.

Also, the Replace method doesn't change the string, it returns the new string, so you have to use the result of the method:

str = str.Replace("\\\\", "\\");

Still, the string literal that you showed doesn't contain any double backslashes, so that will not have any effect at all.

What has made you come to the conclusion that the database has any problems with double backslashes, and why do you think that your string contains any?

---
single minded; short sighted; long gone;

Hard drive serial number

Yosh_27-Jul-07 2:37

Yosh_

27-Jul-07 2:37

Hey all,
OK, I know how to get the hard drives installed on a system. Please I need to know how to retrieve the serial number of a hard disk. Can I use DriveInfo? Don,t think so.

Thanx a lot,
all d best.

Bekjong27-Jul-07 2:46

Bekjong

27-Jul-07 2:46

No, you can't use DriveInfo. You'll probably have to use a p/invoke function. Check out this one.

Standards are great! Everybody should have one!

Mike Dimmick27-Jul-07 3:09

27-Jul-07 3:09

You can only get the drive's serial number (printed on the case) if the drive manufacturer provides a way to do this.

You can get the volume serial number, generated by Windows, using the GetVolumeInformation function. Here[^] is a P/Invoke declaration for that function.

Microsoft defines a volume like so:

"An area of storage on a hard disk. A volume is formatted by using a file system, such as FAT or NTFS, and has a drive letter assigned to it. You can view the contents of a volume by clicking its icon in Windows Explorer or in My Computer. A single hard disk can have multiple volumes, and volumes can also span multiple disks."

- from Windows XP's Help and Support Center.

Note that even this is not the full story, as a volume may not have a drive letter. Since Windows 2000, a volume can appear as a directory under another volume (if the first volume is formatted with NTFS) - this is referred to as a volume mount point.

Stability. What an interesting concept. -- Chris Maunder

zeno_nz28-Jul-07 0:06

zeno_nz

28-Jul-07 0:06

try this article http://www.codeproject.com/csharp/hard_disk_serialno.asp

Yosh_30-Jul-07 1:58

Yosh_

30-Jul-07 1:58

Zeno, thanx a lot really appreciate your help.

Thanx a lot,
all d best.