[R] Please guide -- Error during export in csv format

[Duncan Murdoch]

On 21/03/2016 7:53 AM, Sunny Singha wrote:
> Please guide,
> I'm exporting data in '.csv' format in the Windows user directory, I
> have full access to. The write operation happens within a for loop.
>
> Each iteration exports data in csv format in the user directory. The
> issue is that the  data gets exported for all the 9 iterations but
> fails for 10th iteration giving below error message.
>
> Error in file(file, ifelse(append, "a", "w")) :
>    cannot open the connection
> In addition: Warning message:
> In file(file, ifelse(append, "a", "w")) :
>    cannot open file './/posts_H<U+1ED9>i nh<U+1EEF>ng ngu<U+1EDD>i
> d<U+1ED3>ng hành cùng line_752518568125567.csv': Invalid argument
> Called from: file(file, ifelse(append, "a", "w"))
>
> The export directory path is current directory with 'name' extracted as below:
> my.file1:  .//likes_H<U+1ED9>i nh<U+1EEF>ng ngu<U+1EDD>i d<U+1ED3>ng
> hành cùng line_752518568125567.csv
> my.file2:  .//posts_H<U+1ED9>i nh<U+1EEF>ng ngu<U+1EDD>i d<U+1ED3>ng
> hành cùng line_752518568125567.csv
>
> I wondering if the error is due to the the complicated filename ?
> Below is the line of code I have used within loop to export data.
>
>     my.file1 <- file.path('./', paste0('likes','_',name,'_',grp_id,'.csv'))
>      my.file2 <- file.path('./', paste0('posts','_',name,'_',grp_id,'.csv'))
>
>      write.csv(posts_frame, file=my.file2, row.names = F)
>      write.csv(likes_frame, file = my.file1, row.names = F)
>

The <U+1ED9> and similar strings represent Unicode characters.  I would 
guess that they are being translated to the <U+1ED9> format before being 
used as a filename, and the < and > symbols are not allowed in filenames 
in Windows.

This is a limitation of the way R handles non-ASCII characters in 
Windows, and there's not much you can do about it other than avoiding 
characters which do not display in Latin1 (or whatever R sees as your 
native character set).

Duncan Murdoch