R cant loop concatenate directory and file name

Question

I am trying to loop paste a directory folder path and some csv file names from this folder below, but getting error. Please help!

#

# Create String of Directory fpath

strdir <- getwd()

vec_files <- dir(path = getwd(), pattern = "*.csv") 

# Loop

for (i in 1:length(vec_files)) {

  print0(strdir,"/",vec_files[[i]], sep = "")

}

Returns error below:

Error in print.default(strdir, "/", vec_files[[i]], sep = "") :
invalid printing digits -2147483648 In addition: Warning message: In print.default(strdir, "/", vec_files[[i]], sep = "") : NAs introduced by coercion

Answer 1

As mentioned by @teofil you probably want to use paste0 instead of print0 as there is no function named print0. Moreover, even after using paste0 the loop will not print anything since in for loop you need to print the objects explicitly so wrap another print or cat around paste0 for it to work.

However, you really don't need to do this. dir() and list.files() have full.names parameter which gives the full path of the files if set to TRUE.

vec_files <- dir(path = getwd(), pattern = "\\.csv$", full.names = TRUE)

Also note that if you are reading from your working directory itself you don't necessarily need the complete path of the file, although it is a good habit to work with complete path always.