How to convert backslash to slash?

x <- readline("Input File: ")

x

gsub("\\\\", "/", x)  # notice the double escape

On Wed, 24 Sep 2008, Duncan Murdoch wrote:

Shengqiao Li wrote:

On Tue, 23 Sep 2008, Duncan Murdoch wrote:

On 23/09/2008 4:00 PM, Shengqiao Li wrote:

How to use sub, gsub, etc. to replace "\" in a string to "/"?

For example,convert "C:\foo\bar" to "C:/foo/bar".

If those are R strings, there are no backslashes in the first one.  It
has a formfeed and a backspace in it.

I did notice that this string  was special. It's a legimate R string. If
"f" and "b" are replaced by "d", it will not.

I didn't say it was not legitimate, I said that it contains no
backslashes. If you replace f or b with d, you do not have a legitimate
string.

My purpose is to convert a Windows file path (eg. copied from Explorer
location bar) to a R file path through some R function inside R terminal.
The "File->Change dir..." takes a file path like "C:\Acer", but setwd
function will fail.

That's not true.  If you enter a backslash in the string, setwd() works
fine.

Your problem is that you are confusing R source code with the strings that
it represents.  The R source code for the file path C:\Acer is "C:\\Acer".
 The
R source code "C:\foo\bar" contains no backslashes, it contains the
characters C, :, formfeed, o, o,  backspace, a, r.

If you have the string C:\Acer in the Windows clipboard, then you can read
it from there using readClipboard().  (There are many other ways to read the
clipboard as well;
using 'clipboard' as a filename generally works.) You can then pass it to
setwd(), and it will be fine.

Thank you for your reply. readClipboard is a partial solution to this case.
More generally, if I want to wrtie a R program in which users are asked to
input a file path. I want this program to be robust and tolerant, that is
users can type in C:\Acer or C:/Acer.  What's the way to do this?

Shengqiao Li

Duncan Murdoch

I guess there must be some ways in R to replace a backslash by slash, eg.
C:\Acer -> C:/Acer. The first problem may be how to pass and save this kind
of strings. encodeString does not work for this, it will just ignore "\".
 Shengqiao Li

Duncan Murdoch