using paste and "\" to create a valid filename

I was surprise myself that I was having problems, because I have been
doing this for ahile, but I get erros with the RODBC connection.  For
example,

rankFile <- paste("R:\\New Ranks\\SMC\\SMC\\",rankDate,".xls", sep="")				
			rankFile
			xls <- odbcConnectExcel(rankFile)
			xls
			rankFile <- "R:\New Ranks\SMC\SMC\20050818.xls"			
			rankFile
			xls <- odbcConnectExcel(rankFile)
			xls


You won't have my filename, but feel free to try it with any excel
file you may have. Here is the R output.

rankFile <- paste("R:\\New Ranks\\SMC\\SMC\\",rankDate,".xls", sep="")
rankFile

[1] "R:\\New Ranks\\SMC\\SMC\\20050819.xls"

xls <- odbcConnectExcel(rankFile)

Warning messages:
1: [RODBC] ERROR: Could not SQLDriverConnect 
2: ODBC connection failed in: odbcDriverConnect(con) 

xls

[1] -1

rankFile <- "R:\New Ranks\SMC\SMC\20050818.xls"
rankFile

[1] "R:New RanksSMCSMC?50818.xls"

xls <- odbcConnectExcel(rankFile)
xls

RODB Connection 15
Details:
  case=nochange
  DBQ=R:New RanksSMCSMC?50818.xls
  DefaultDir=R:\NEW RANKS\SMC
  Driver={Microsoft Excel Driver (*.xls)}
  DriverId=790
  MaxBufferSize=2048
  PageTimeout=5


On 8/19/05, Uwe Ligges <ligges at statistik.uni-dortmund.de> wrote:

roger bos wrote:

Sometimes even the easy stuff is difficult (for me)... I want to get
input from different places to paste together an excel filename (so
you know I'm using windows) that I can open with RODBC.  I know about
using double "\" since its an escape character, but I get either 2 or
none, I can't get just one "\" where I need it.  See example code
below.  I am using R 2.1.0, but plan to upgrade soon.  Thanks in
advance to anyone who can help.

Roger


rankPath <- "R:\New Ranks\SMC\SMC"
rankDate <- "20050819"
rankFile <- paste(rankPath,rankDate,".xls", sep="")
rankFile
[1] "R:New RanksSMCSMC20050819.xls"


rankPath <- "R:\\New Ranks\\SMC\\SMC"
rankDate <- "20050819"
rankFile <- paste(rankPath,rankDate,".xls", sep="")
rankFile
[1] "R:\\New Ranks\\SMC\\SMC20050819.xls"

This is perfect, "\" is *printed* escaped, hence for file access you can
perfectly use this character vector.

Uwe Ligges