chickadee » posix » file-open

file-open FILENAME FLAGS #!optional MODEprocedure

Opens the file specified with the string FILENAME and open-flags FLAGS using the C function open(2). On success a file-descriptor for the opened file is returned.

FLAGS is a bitmask of open/... values ored together using bitwise-ior (or simply added together). You must provide exactly one of the access flags open/rdonly, open/wronly, or open/rdwr. Additionally, you may provide zero or more creation flags (open/creat, open/excl, open/trunc, and open/noctty) and status flags (the remaining open/... values). For example, to open a possibly new output file for appending:

(file-open "/tmp/hen.txt" (+ open/wronly open/append open/creat))

The optional MODE should be a bitmask composed of one or more permission values like perm/irusr and is only relevant when a new file is created. The default mode is perm/irwxu | perm/irgrp | perm/iroth.