nc.traditional -V (return code: 1)
nc.traditional: invalid option -- '-' nc -h for help
nc.traditional -h (return code: 0)
[v1.10-41] connect to somewhere: nc [-options] hostname port[s] [ports] ... listen for inbound: nc -l -p port [-options] [hostname] [port] options: -c shell commands as `-e'; use /bin/sh to exec [dangerous!!] -e filename program to exec after connect [dangerous!!] -b allow broadcasts -g gateway source-routing hop point[s], up to 8 -G num source-routing pointer: 4, 8, 12, ... -h this cruft -i secs delay interval for lines sent, ports scanned -k set keepalive option on socket -l listen mode, for inbound connects -n numeric-only IP addresses, no DNS -o file hex dump of traffic -p port local port number -r randomize local and remote ports -q secs quit after EOF on stdin and delay of secs -s addr local source address -T tos set Type Of Service -t answer TELNET negotiation -u UDP mode -v verbose [use twice to be more verbose] -w secs timeout for connects and final net reads -C Send CRLF as line-ending -z zero-I/O mode [used for scanning] port numbers can be individual or ranges: lo-hi [inclusive]; hyphens in port names must be backslash escaped (e.g. 'ftp\-data').