Discussion Forum (LMS)
iClickers in Lecture
Advice from TAs
Advice from Students
Collaboration Policy &
Due Date and Time
Late Day Policy
HW Grading Criteria
Code Editors & IDEs
Misc. C++ Programming
Command Line Args
string → int/float
Downloading and Installing or Upgrading Cygwin
NOTE: Cygwin is available in both a 32-bit version and a 64-bit
version. If you have a 64-bit operating system (most of us do!) then
you may use either version of Cygwin for this course. CAUTION: If you
start with one and accidentally use the other Cygwin installer, you
will end up with 2 versions of Cygwin on your machine which is super
If you have the
RPI Mobile Computing
Program Laptop with the provided software image, you may already
have Cygwin installed, but we'll need to upgrade and add a few
additional packages. First, let's find out whether you have the
32-bit or 64-bit version of Cygwin.
Go to the start menu/search bar and search for "Cygwin". If you have
a program named "Cygwin Terminal" you have 32-bit Cygwin. If it's
named "Cygwin64 Terminal" you have 64-bit Cygwin. To confirm the
version, click to launch the Cygwin terminal, and then type:
If the output includes PE32 and 80386 you have
32-bit Cygwin. If the output says PE32+ and x86-64
then you have 64-bit Cygwin.
and download the 32-bit setup-x86.exe OR the 64-bit
Double click the setup file, click Next to enter the setup program.
The "Install From Internet" box should be selected, then click Next.
Your Root Directory should be C:\cygwin (or
C:\cygwin64 for the 64-bit version) & the box to install for "All
users" should be selected, then click Next.
The Local Package Directory will be used to store packages downloaded
from the internet. You may put this anywhere on your machine (the default is probably fine).
The "Direct Connection" box should be selected, click Next.
Then, pick a mirror, any mirror, and then click Next again.
There's a ton of info on this next page of packages to choose and
such, just keep the "Curr" choice selected at the top right.
You will need to install a number of extra packages for your work in this course:
First, type "zip" in the search box near the top of the
installation window. Open up the "Archive" section, then locate the
"zip" package. The description should be
"zip: Info-ZIP compression utility"
. Click on the word "Skip" on that line to indicate we want
to install zip rather than skipping it. A version number should
appear, like "220.127.116.11".
Next, type "g++" in the search box. Open up the "Devel"
section, and click on "Skip" for
"gcc-g++: GNU Compiler Connection
(C++)" until the version number appears.
Also, click on "Skip" for
"mingw-gcc-g++: GNU Compiler
Connection". (This is needed to run
the Dr. Memory memory debugger.)
Then, type "gdb" in the search box. Open up the "Devel" section, and
"gdb: The GNU Debugger" for installation.
Then, type "clang" in the search box. Click "Skip" for
"clang: C/C++/ObjC compiler frontend based on LLVM" until the
version number appears.
Then go ahead and hit Next. If a "Resolving Dependencies" window
shows, make sure the "Select required packages" box is checked, hit
Next again and take a coffee break. Your computer is going to download
a plethora of packages, and then install them. It may tell you that
you have to reboot after the install, if it does, do so. After
updating an existing Cygwin installation, be sure to close & re-open
any Cygwin terminals so you have the new packages.
Click finish and pat yourself on the back, you've finished a
complete Cygwin install.
Helpful edits to the Cygwin .bashrc file
NOTE: You'll need to close & reopen your Cygwin terminal after
making the edits below.
First, locate your .bashrc file for the current user.
This is probably c:\Cygwin\home\YOUR_USERNAME\.bashrc (or just
~/.bashrc from the Cygwin shell). Make a copy of this file and put it
somewhere safe before making the changes below, so you can undo in
case anything goes wrong.
Use Notepad++ or Sublime (or another UNIX-friendly plaintext editor)
to edit the .bashrc file, and NOT Notepad or Wordpad. If you
see weird errors like "\r command not found", navigate to the
directory containing the .bashrc file and run the following
tr -d '\r' < .bashrc > .bashrc
and then restart Cygwin.
To quickly navigate to your Data Structures files, you can add
a variable that points to that directory in your .bashrc file:
Then at the Cygwin prompt, you can use that variable:
To make an alias for the MinGW compiler with the options necessary for Dr. Memory,
add this to your .bashrc file:
alias memg++='i686-pc-mingw32-g++.exe -static-libgcc -static-libstdc++ -ggdb'
Then when you're ready to compile code for use with Dr. Memory, you
can type something like this at the Cygwin prompt:
memg++ -o foo.exe foo_main.cpp foo_other.cpp
After installing Dr. Memory (see instructions
Dr. Memory on Windows),
if you see this error message when trying to run Dr. Memory:
-bash: drmemory: command not found
You can manually add Dr. Memory to your Cygwin path (which is
different from your Windows path that the Dr. Memory installer may
have already edited automatically). At the end of
the .bashrc, add this line:
PATH=$PATH:/cygdrive/c/Program\ Files\ \(x86\)/Dr.\ Memory/bin