stdin() is not the same as file("stdin"), see the note in ?stdin.Gabor On Mon, 28 May 2018, 10:41 Martin Maechler, <maech...@stat.math.ethz.ch> wrote: > >>>>> Martin Maechler > >>>>> on Mon, 28 May 2018 10:28:01 +0200 writes: > > >>>>> Ralf Stubner > >>>>> on Fri, 25 May 2018 19:18:58 +0200 writes: > > >> Dear all, I would like to draw you attention to this > >> question on SO: > >> > https://stackoverflow.com/questions/50372043/readlines-function-with-new-version-of-r > > > >> Based on the OP's code I used the script > > >> ####################################### > >> create_matrix <- function() { > >> cat("Write the numbers of vertices: ") > >> user_input <- readLines("stdin", n=1) > >> user_input <- as.numeric(user_input) > >> print(user_input) > >> } > >> create_matrix() > >> ####################################### > > >> and called it with "R -f <filename>" from the command line. > > >> With 'R version 3.4.4 (2018-03-15) -- "Someone to Lean On"' the > script > >> prints the inputed number as expected. With both 'R version 3.5.0 > >> (2018-04-23) -- "Joy in Playing"' and 'R Under development > (unstable) > >> (2018-05-19 r74746) -- "Unsuffered Consequences"' the script does > not > >> continue after inputing a number. > > > I can confirm. > > It "works" if you additionally (the [Enter], i.e., EOL) you also > > "send" an EOF -- in Unix alikes via <Ctrl>-D > > > The same happens if you use 'Rscript <filename>' > > > I'm not the expert here, but am close to sure that we (R core) > > did not intend this change, when fixing other somewhat subtle > > bugs in Rscript / 'R -f' > > > Martin Maechler > > The same behavior in regular R , no need for a script etc. > > > str(readLines("stdin", n=1)) > > then in addition to the input you need to "give" an EOF (Ctrl D) in R >= > 3.5.0 > > Interestingly, everything works fine if you use stdin() instead > of "stdin" : > > > rr <- readLines(stdin(), n=1) > foo > > rr > [1] "foo" > > > ---------- > > So, for now use stdin() which is much clearer than the string > "stdin" anyway > > Martin Maechler > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
