2008/10/28 Greg Snow <[EMAIL PROTECTED]>:
> I have some functions that write an external text file for postprocessing by
> another program. Some instructions to the other program need to be indicated
> by null values (\000 or ^@). The function currently uses code like:
>
> writeChar(rawToChar(as.raw(0)), con)
>
> where con is a connection to the file. Previous to version 2.8.0 this worked
> fine. With 2.8.0 it still works, but I get a warning message about
> "truncating string with embedded null: '\0'" every time. This is documented
> and not a bug, but I still find it annoying.
>
> One thing I could do is to turn off all warnings before doing this, but then
> if there is some other warning generated, then I will miss the other
> warning(s).
>
> Is there a better way to write the null to the text file? Or is there a way
> to suppress just this warning without suppressing any other warnings that may
> occur?
The warning happens when you construct the string, so somehow you
have to avoid making the string. How about using writeBin with a
connection opened in binary mode:
> con=file("test2.raw","wb")
> writeBin(as.raw(1),con,size=1)
> writeBin(as.raw(0),con,size=1)
> writeBin(as.raw(0),con,size=1)
> writeBin(as.raw(7),con,size=1)
> close(con)
>
Save workspace image? [y/n/c]: n
now lets dump it:
[EMAIL PROTECTED]:~$ od -x test2.raw
0000000 0001 0700
0000004
Which I think is correct, maybe some fiddling with endianness is needed...
Barry
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