MINITALK

first launch server :

./server

it will print a line with its own pid, and an empty line below

if you want to terminate the program hit ctrl-c

then in another window launch the client, with two arguments :

./client [SERVER PID] [string]

[SERVER PID] is the pid number printed by the server

[string] is whatever you want to write, surrounded by " if you want to include spaces : "a random phrase"

use of getpid : https://www.includehelp.com/c/getpid-and-getppid-functions-in-c-linux.aspx
use of signal : https://linuxhint.com/signal_handlers_c_programming_language
use of sigaction : https://stackoverflow.com/a/17572787/9497573
signal action on sleep : https://unix.stackexchange.com/questions/351312/sigint-handler-runs-only-once
signals are pending just on per type : https://stackoverflow.com/questions/5285414/signal-queuing-in-c
checking for pending signals : https://www.gnu.org/software/libc/manual/html_node/Checking-for-Pending-Signals.html
don't use pause : https://www.gnu.org/software/libc/manual/html_node/Pause-Problems.html
standard signal vs real time signals (with queue option) : https://www.softprayog.in/programming/posix-real-time-signals-in-linux
test time of functions in program : https://stackoverflow.com/a/5833240/9497573