Good morning, You do not need to quote a forward slash / in R, but you do need to quote a backslash when you're inputting it... so to get a string which actually contains "blah\/blah"... you need to use "blah\\/blah"
http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-does-backslash-behave-strangely-inside-strings_003f Unless this is a very very big file you shouldn't need to go out to sed, as gsub() should work adequately... and probably quicker and cleaner. So something along the lines of.. (UNTESTED!!! since I don't have a reproduceable example) tmp1 <- readLines(configurationFile) tmp1 <- gsub("^instance .*", paste("instance = ", data$instancePath, "/", data$newInstance, sep = ""), tmp1) I'm working on 50mb text files, and doing all sorts of manipulations and I do it all inside R under windows XP... reading a 50mb text file across the 100mb network and doing a gsub() on most lines takes an elapsed 16 seconds on this office desktop. hth... Regards, Sean ikarus wrote: > > Hi guys, > I've been struggling to find a solution to the following issue: > I need to change strings in .ini files that are given in input to a > program whose output is processed by R. The strings to be changed looks > like: > "instance = /home/TSPFiles/TSPLIB/berlin52.tsp" > > I normally use Sed for this kind of things. So, inside R I'd like to write > something like: > > command <- paste("sed -i 's/^instance .*/instance = ", data$instancePath, > data$newInstance, "/' ", configurationFile, sep = "") > system(command) > > This will overwrite the line starting with "instance " using "instance = > the_new_instance" > In the example I gave, data$instancePath = /home/TSPFiles/TSPLIB/ and > data$newInstance = berlin52.tsp > > The problem is that I need to pass the above path string to sed in the > form: > "\/home\/TSPFiles\/TSPLIB\/" > > However, I couldn't find a way to "create" such a string in R. I tried in > several different ways, > but it always complains saying that '\/' is an unrecognized escape! > > Any suggestion? > > Thanks! > -- View this message in context: http://www.nabble.com/How-to-create-a-string-containing-%27%5C-%27-to-be-used-with-SED--tp20694319p20696613.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.