ENEE 350H - Programming in ENEE 350H

Programming in ENEE 350H

First, you may want to link to the following directory. Put the following at the end of your .cshrc file:

    set path = ( /afs/glue.umd.edu/department/enee/public_html/courses/enee350h.F97/bin $path )

In this bin directory, you will find two shell scripts:

ccc, a wrapper around the gcc compiler, and
submit350, which you will use to submit your project files.

ccc

The ccc wrapper simply calls gcc with a few nice flags, including -lm and -g. The -lm flag means "link with a certain library (-l) called libm.a (m), which happens to be the math library." This way, if you use math functions like sqrt or rand, you won't get errors about missing symbols:

    Undefined                       first referenced
     symbol                             in file
    sqrt                                myprog.o
    ld: fatal: Symbol referencing errors. No output written to myprog
    *** Error code 1
    make: Fatal error: Command failed for target `myprog'

There are other useful libraries besides the math library:

libc.a (-lc) - contains a number of C routines, I think kind of archaic these days
libsocket.a (-lsocket) - contains the various Berkeley sockets routines, like socket, send, recv, select, and gettimeofday. These are extremely useful when you write networking code.

Note that on some systems, the math library is called libmath.a, which means that you have to specify it on the command-line by -lmath.

The -g flag tells the compiler to leave in the symbol information, which you will find very useful if you use debuggers.

submit350

The submit350 script is to be used to submit your program files once you have finished creating them. It is to be used in the following manner. Assume that you are submitting four files:

unagi.c - a simulator
sake.c - an assembler
tako.s - an assembly-code file that composes music

Then you type the following:

    submit350 unagi.c
    submit350 sake.c
    submit350 tako.s

You will receive as an ackowledgment an email message for each file submitted, giving the file's name, contents, and approximate submission time. Check this acknowledgment for accuracy -- make sure that what you actually submitted is what you intended to submit.