---------------------------------------- links -----------------------------
https://en.wikipedia.org/wiki/Everything_is_a_file
https://en.wikipedia.org/wiki/Inode
https://yarchive.net/comp/linux/everything_is_file.html

---------------------------------------- docker demo -----------------------------
docker run -it busybox:latest

ps aux | grep busy
cd /proc/$PROCID
ls -l fd
cat stat 
cat limits

---------------------------------------- PS states  -----------------------------
states
D    uninterruptible sleep (usually IO)
I    Idle kernel thread
R    running or runnable (on run queue)
S    interruptible sleep (waiting for an event to complete)
T    stopped by job control signal
t    stopped by debugger during the tracing
W    paging (not valid since the 2.6.xx kernel)
X    dead (should never be seen)
Z    defunct ("zombie") process, terminated but not reaped by its parent

<    high-priority (not nice to other users)
N    low-priority (nice to other users)
L    has pages locked into memory (for real-time and custom IO)
s    is a session leader
l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
+    is in the foreground process group

---------------------------------------- compile & trace -----------------------------
go build helloGo.go
odin build helloOdin.odin -file -out:hello

ldd ./hello
ldd ./helloGo

ltrace -S ./helloGo
ltrace -e ./helloGo
readelf -s ./hello | less
readelf -s ./helloGo | less