ig2ar-saf1 at yahoo.co.uk
2009-Mar-10 20:01 UTC
[R] system() not accepting strings from cat()
Hi again R-ists, How do you construct a string that you can pass to system()? For instance. Say I do> system("echo Hello!")Hello! That works. Now the alternative: I need to construct the string like this> a <- "echo" > b <- "Hello!" > c <- "\n" > cat(a, b, c)echo Hello! Looks nice... but see what happens when I try to use it> system(cat(a, b, c))echo Hello! Error in system(command, intern) : non-empty character argument expected I have googled extensively in and out of r-lists but I can't find a solution. Can anybody help?
try ?paste baptiste On 10 Mar 2009, at 20:01, ig2ar-saf1 at yahoo.co.uk wrote:> > Hi again R-ists, > > How do you construct a string that you can pass to system()? > > For instance. Say I do > >> system("echo Hello!") > Hello! > > That works. Now the alternative: I need to construct the string like > this > >> a <- "echo" >> b <- "Hello!" >> c <- "\n" >> cat(a, b, c) > echo Hello! > > Looks nice... but see what happens when I try to use it > >> system(cat(a, b, c)) > echo Hello! > Error in system(command, intern) : non-empty character argument > expected > > I have googled extensively in and out of r-lists but I can't find a > solution. > > Can anybody help? > > > > > ______________________________________________ > R-help at 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._____________________________ Baptiste Augui? School of Physics University of Exeter Stocker Road, Exeter, Devon, EX4 4QL, UK Phone: +44 1392 264187 http://newton.ex.ac.uk/research/emag