unix-debugging-tools.txt

http://jvns.ca/debugging-zine.pdf
http://www.tldp.org/LDP/Linux-Filesystem-Hierarchy/html/proc.html
http://www.brendangregg.com/linuxperf.html
http://www.brendangregg.com/Perf/linux_perf_tools_full.png


https://www.devopszen.com/network-monitoring-tools


***AWESOME***
https://github.com/iovisor/bcc


*** perf + process monitor
top
htop
perf - Performance analysis tools for Linux
http://www.brendangregg.com/flamegraphs.html

*** i/o + syscalls
dstat - versatile tool for generating system resource statistics
strace - trace system calls and signals
opensnoop - trace open() syscalls with file details. Uses Linux ftrace.
execsnoop - trace process exec() with arguments. Uses Linux ftrace.
lsof - list open files
fuser - identify processes using files or sockets
sysdig - the definitive system and process troubleshooting tool

*** networking
nc — arbitrary TCP and UDP connections and listens
ss - another utility to investigate sockets

netstat - Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships
sudo netstat -tunapl # shows process and port assignments
lsof -i -P # same, but OSX

ngrep - network grep # a spy tool for network i/o
tcpdump - dump traffic on a network

wireshark

curl
httpie


MORE *****


dstat
opensnoop
strace
ngrep
netstat
tcpdump
wireshark
eBPF
/proc ===> /proc/PID/stack # to view stack trace of live process
perf
ps
top, htop, perf top
flamegraph

#### SYSCALLS

socket
open
execve
sendto
read
recvfrom
write

Debugger — gdb, valgrind, ltrace, lsof, pmap

pmap - process map
lsof -p 1234 # show all files open by process num