Filenames¶
Filenames are handled more strictly in Idio than many other languages. The Idio source code is expected to be encoded in UTF-8 and correspondingly, the strings-as-filenames passed to functions will be UTF-8 encoded strings.
Filenames in Unix-oriented filesystems have no encoding whatsoever,
they are simple arrays of bytes (excluding ASCII NUL) and using /
as a directory separator.
Any filename retrieved from the operating system will be tagged as a pathname, a variant of strings. A pathname and a string are not the same and will fail equivalence tests.
That’s inconvenient so there are some facilities to construct pathnames from Idio strings:
%P"..."
constructs a pathname-tagged string using the same escape codes available to stringsstring->pathname
will return a pathname-tagged string from the string passed as an argument
fn := "words.txt"
pn := string->pathname fn
ofh := open-output-file fn
hprintf ofh "this is contents\n"
close-handle ofh
files := glob "*.txt"
for file in files {
puts "File: "
write file ; prints %P"..." rather than ...
(newline)
printf "equal? %s? %s\n" fn (equal? file fn)
printf "equal? %s? %s\n" pn (equal? file pn)
}
$ idio file-names
File: %P"words.txt"
equal? words.txt? #f
equal? words.txt? #t
Note that the printed representation of fn
and pn
are the same. Had we used write
to get the reader-friendly
representation we’d have seen the difference. The predicate
pathname?
may be useful.
Last built at 2024-12-13T07:11:33Z+0000 from 77077af (dev) for Idio 0.3