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+# Installation
+
+* Clone the `cidrchk` git repository
+* `sudo python setup.py install`
+
+If you are unable to install `cidrchk` as root, please use the following notation instead:
+
+* `python setup.py install --user`
+
+# What is cidrchk?
+
+`cidrchk` is a simple Python script with only one purpose: To inform a user whether or not their computer is connected to a particular network. For example, on your "work" laptop, you depend on autofs to automatically mount NFS directories. However, when you are off-site or not connected to your institution's VPN, you quickly realize attempting to access these data areas will cause significantly long delays (i.e. the *five minute* default timeout period)
+
+# Options
+
+```
+usage: cidrchk [-h] [--ignore IGNORE] [--debug] [--verbose] cidr [cidr ...]
+
+Detects whether or not any ethernet devices match to a defined CIDR range.
+
+positional arguments:
+  cidr                  IP range(s) to detect
+
+optional arguments:
+  -h, --help            show this help message and exit
+  --ignore IGNORE, -i IGNORE
+                        IP range(s) to ignore (Default: link-local and
+                        localhost)
+  --debug, -d
+  --verbose, -v
+```
+
+# How do I use it?
+
+Consider the following **.cshrc** example:
+
+```
+setenv PATH $HOME/bin:${PATH}
+setenv MYDATA /remote/data1
+alias badidea "cd ${MYDATA}"
+```
+
+What happens if you, out of habit, attempt to execute your favorite alias?
+
+```
+$ badidea
+[ no output, waiting for autofs to timeout ]
+```
+
+Whoops! Things didn't go as planned, so let's take a look at the same **.cshrc** example using `cidrchk`:
+
+```
+setenv PATH $HOME/bin:${PATH}
+setenv MYDATA /remote/data1
+
+set _OFFSITE = `cidrchk 10.0.0.0/20 66.55.32.0/20 >/dev/null`
+setenv OFFSITE $status
+unset _OFFSITE
+
+alias badidea "cd ${MYDATA}"
+
+if ( ${OFFSITE} ) then
+    unalias badidea
+endif
+```
+
+In the above example the following is *true*: 
+
+If 10.0.0.0/20 represents your institution's VPN address space and 66.55.32.0/20 represents your company's local intranet, and your home IP was 192.168.1.101, `cidrchk` returned a non-zero value indicating your computer was "off-site".
+
+Inversely, if your computer's IP address was 66.55.45.10 (i.e. you are in your cubicle), `cidrchk` would return zero indicating your computer was "on-site".
+
+## Other Possiblities
+
+Issuing `-v` to `cidrchk` will echo the return value to the console, resulting in slightly more cleaner code:
+
+```
+setenv OFFSITE `cidrchk -v 10.0.0.0/24 66.55.32.0/20`
+
+if ( ${OFFSITE} ) then
+    # do something clever to prevent personal hardship
+endif
+```
+
+## How do I use BASH with cidrchk?
+
+The notation required for `cidrchk` to use BASH is nearly identical to TCSH:
+
+```
+_OFFSITE=$(cidrchk 10.0.0.0/24 66.55.32.0/20 >/dev/null)
+export OFFSITE=$?
+
+if (( ${OFFSITE} )); then
+    #do something clever to prevent personal hardship
+fi
+```
+
+# Bug Reporting
+
+Submit bug reports via this project's issue tracker: https://bitbucket.org/jhunkeler/cidrchk/issues
+
+Please remember to include your computer's operating system, the name of the shell you executed `cidrchk` from, the output of `cidrchk -d`, and any relevant code snippets you may have.
+