dirent¶

read the current directory entry via syscalls (//#use dirent)
NAME
    dirent - read the current directory entry via syscalls (//#use dirent)

SYNOPSIS
    //#use dirent       cc splices /lib/lib_dirent.c

DESCRIPTION
    Reads the current directory entry through OS syscalls instead of
    poking BIOS scratch addresses directly.

    A BIOS FNEXT leaves the matched entry's metadata in fixed BIOS
    scratch RAM (FNAME, FFLAG, FLEN, the start LBA). Commands used to
    peek()/poke() those absolute addresses, which coupled every command
    to the firmware's scratch layout -- a memory remap had to move ~30
    hardcoded sites in lockstep. These helpers go through two syscalls:

        SYS_DIRENTRY ($201B)  copy the current entry into a buffer
        SYS_OPENDIR  ($201E)  begin iterating a subdirectory by its LBA

    so the firmware can relocate its scratch freely without touching a
    command.

USAGE
    After each `bios(FNEXT, 0, 0)` that returned "not end", call de_read()
    once, then query the snapshot:

    de_read()           snapshot the current entry into de[]
    de_isfile()         1 if the entry is a file
    de_isdir()          1 if the entry is a directory
    de_isdot()          1 for "." and ".." (only the first char is tested)
    de_len()            file length in bytes (little-endian)
    de_lba()            start LBA (the dir's first block)
    de_opendir(lba)     open subdirectory `lba` for FNEXT iteration
    de[0..11]           the entry name, space-padded

    de[] is an 18-byte buffer: [0..11] name, [12] flag (1=file 2=dir),
    [13..14] length lo/hi, [15..16] start-LBA lo/hi, [17] spare. Accessors
    mask with &255 because A/B are 8-bit and this is a C subset with no
    unsigned char.

SEE ALSO
    apath, glob, globx, dir, find