# tar -xzvf netcat-0.7.1.tar.gz
[root@znode02 netcat-0.7.1]# ls
ABOUT-NLS   config.guess  configure     INSTALL     Makefile.am    NEWS    TODO
aclocal.m4  config.h.in   configure.ac  install-sh  Makefile.in    po
AUTHORS     config.rpath  COPYING       lib         missing        README
ChangeLog   config.sub    doc           m4          mkinstalldirs  src
# mkdir /apps
# ./configure --prefix=/apps/nc
[root@znode02 netcat-0.7.1]# ls
ABOUT-NLS     config.h       config.sub    INSTALL     Makefile.am    po
aclocal.m4    config.h.in    configure     install-sh  Makefile.in    README
AUTHORS       config.log     configure.ac  lib         missing        src
ChangeLog     config.rpath   COPYING       m4          mkinstalldirs  stamp-h1
config.guess  config.status  doc           Makefile    NEWS           TODO
]# make && make install
# tree /apps/nc
/apps/nc
├── bin
│   ├── nc -> netcat
│   └── netcat
├── info
│   ├── dir
│   └── netcat.info
├── man
│   └── man1
│       └── netcat.1
└── share└── locale├── it│   └── LC_MESSAGES│       └── netcat.mo└── sk└── LC_MESSAGES└── netcat.mo10 directories, 7 files

# cat /root/.bash_profile
# .bash_profile# Get the aliases and functions
if [ -f ~/.bashrc ]; then. ~/.bashrc
fi# User specific environment and startup programsPATH=$PATH:$HOME/bin
NC=/apps/nc
PATH=$PATH:$NC/bin
export PATH

# source ~/.bash_profile

# nc -h
GNU netcat 0.7.1, a rewrite of the famous networking tool.
Basic usages:
connect to somewhere:  nc [options] hostname port [port] ...
listen for inbound:    nc -l -p port [options] [hostname] [port] ...
tunnel to somewhere:   nc -L hostname:port -p port [options]Mandatory arguments to long options are mandatory for short options too.
Options:-c, --close                close connection on EOF from stdin-e, --exec=PROGRAM         program to exec after connect-g, --gateway=LIST         source-routing hop point[s], up to 8-G, --pointer=NUM          source-routing pointer: 4, 8, 12, ...-h, --help                 display this help and exit-i, --interval=SECS        delay interval for lines sent, ports scanned-l, --listen               listen mode, for inbound connects-L, --tunnel=ADDRESS:PORT  forward local port to remote address-n, --dont-resolve         numeric-only IP addresses, no DNS-o, --output=FILE          output hexdump traffic to FILE (implies -x)-p, --local-port=NUM       local port number-r, --randomize            randomize local and remote ports-s, --source=ADDRESS       local source address (ip or hostname)-t, --tcp                  TCP mode (default)-T, --telnet               answer using TELNET negotiation-u, --udp                  UDP mode-v, --verbose              verbose (use twice to be more verbose)-V, --version              output version information and exit-x, --hexdump              hexdump incoming and outgoing traffic-w, --wait=SECS            timeout for connects and final net reads-z, --zero                 zero-I/O mode (used for scanning)Remote port number can also be specified as range.  Example: '1-1024'