Martin questions

• Understanding sed hold-space work-flow
• difference between "exec" and "exit" in bash
• modify Ethernet FSC in Scapy
• algorithm to find IPv4 networks in CIDR notation between two IPv4 addresses
• listen for returning UDP packets in bash
• How to decrease TCP connect() system call timeout?
• security concerns with Perl /e modifier
• understanding $' ' quotes in bash
• How do I delete newlines ('\n', 0x0A) from non-empty lines using tr(1)?
• Ignore HUP signal in Bash script with pipe commands

Martin answers