On Fri, 29 Jan 2016 16:45:40 -0800 (PST), Scotty C <costo...@hotmail.com> wrote:
>i have a new issue. i wrote my data as char and end records with 'return. i >use (read-line x 'return) and the first record is 15 char. when i use > (read-line-bytes x 'return) i get 23 byte. i have to assume that my old >assumption that an 8 bit char would write to disk as 8 bits is incorrect? Yes and no. Characters are not "bytes". If you wrote the file originally in text mode, then it is subject to locale settings in the OS. Racket can handle some different character representations, but you have to select them deliberately. If you want to work with byte strings you are going to do file I/O in binary mode. Also, note that if you display/print a byte string you are seeing character representations of the bytes. There will be extraneous '\' escapes for values that don't represent printable characters. The small values you will be using all are unprintable ASCII control characters. >from documentation on read-char >Reads a single character from in—which may involve reading several >bytes to UTF-8-decode them into a character > >i get the feeling that i will need to read the entire file as i used to read it >taking each record and doing the following: >- convert the string record to a bignum record >- convert the bignum record into a byte string >- write the byte string to a new data file > >does that seem right? Yes. You probably do need to convert the files. Your original coding likely is not [easily] compatible with binary I/O. George -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
