some cleanup

lots of cleanup

idecref cwd in exit

delete unused functions
a few comments

generate postscript printout

forbid create or write of existing directory
mkdir("d1/d2/d3"), .. should refer to d2, not cwd
mkdir increase parent link count

chdir return -1 if target not a dir

fix race in mknod / creat
use last component in dirent in mknod, not path

fix bug in test code of malloc

test malloc

clean up test program

nit in sbrk
indirect block
fix dup to share fd struct

better parsing of sh commands (copied from jos sh)
cat: read from 1 if no args
sbrk system call, but untested
getpid system call
moved locks in keyboard intr, but why do we get intr w. null characters from keyboard?

renumber system calls (run gmake clean!)
skeleton for dup system call

cd in shell
nits in mkdir, ls, etc.

proc[0] calls iget(rootdev, 1) before forking init

each cpu[] has its own gdt and tss
no per-proc gdt or tss, re-write cpu's in scheduler (you win, cliff)
main0() switches to cpu[0].mpstack

shell parses arguments (very simplistic)
readme version of README (sh doesn't deal with capital characters)
printf recognizes %c
nicer output format for ls

mkdir
ls shows stat info for each dir entry

stat

don't hold fd table lock across idecref() (latter does block i/o)
idecref calls iput() in case last ref -> freeing inode
dir size is 512 * # blocks, so readi/writei &c work
unlink deletes dirent even if ip->nlink > 0

multi-block directories
track size of directory (size = number entries in use)
should namei (and other code that scans through directories) scan through all blocks of a directory and not use size?

don't increase length of directory

read problem, but untested