Hello Project
COP-3402

cd ~/cop3402spring25/hello

If your ~/cop3402spring25 directory does not exist yet, be sure to do git setup first.

emacs hello.c

Create a C program that prints "hello, world!\n" (remember this is case sensitive and don't forget the \n).

Then save and exit (for emacs, Ctrl-x Ctrl-s then Ctrl-x Ctrl-c).

Make sure your compiles and runs correctly:

gcc -o hello hello.c
./hello

exit

(or Ctrl-D on the empty command prompt.)

scriptreplay hello.timing hello.script 2

The 2 is optional and will replay it at 2x speed. You can use a higher number as well to replay faster. Use Ctrl-C to stop playback.

cd ~/cop3402spring25/hello

If your directory does not exist yet, be sure to do git setup first.

emacs Makefile

Hand-type the following Makefile. Use tab for indentation (not spaces), or your Makefile will not work.

.PHONY: all clean

all: hello

hello: hello.c
        gcc -o hello hello.c

clean:
        rm -f hello

Then save and exit (for emacs, Ctrl-x Ctrl-s then Ctrl-x Ctrl-c).

make

You should see the following output. (Do not type this into bash; this is what the Makefile will run for you):

gcc -o hello hello.c

If you receive compiler errors, be sure your hello.c is correct. If you receive make errors, double-check the Makefile contents against the previous step and make sure you are using tab not spaces for indentation.

If you have already built your program and not modified hello.c since, then you will see something like

make: Nothing to be done for 'all'.

or something like this

make: 'hello' is up to date.   

Be sure you are in the root of your repo, in this case ~/cop3402spring25/hello:

cd ~/cop3402spring25/hello

To illustrate what the .gitignore file does, let's make sure the file hello exists (it may already if you have built your program):

touch hello

(touch creates an empty file or updates the timestamp of an existing file).

git status

This should output something like this:

On branch master
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        hello
        Makefile
  hello.c
  hello.script
  hello.timing

nothing added to commit but untracked files present (use "git add" to track)

There may be other content, but be sure that hello is under Untracked files:. This tells you that hello is untracked, i.e., it is in the working tree but not staged or committed. If you don't see this, be sure you are in the root of your repo and that the hello file exists. If it still is not show as untracked, then you may have accidentally added hello to your repo already. Remove it with these instructions.

emacs .gitignore

Put the names (or patterns) of files to exclude from the output, one per line:

*~
hello

*~ ignores emacs backup files. hello ignores the hello file.

Save and exit (for emacs, Ctrl-x Ctrl-s then Ctrl-x Ctrl-c).

git status

This should output something like this:

On branch master
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        .gitignore
        Makefile
  hello.c
  hello.script
  hello.timing

nothing added to commit but untracked files present (use "git add" to track)

Notice that hello is no longer under Untracked files, but now the new file .gitignore is. Add and commit this file so that all users of your repo will see it.

git add .gitignore
git commit .gitignore

Enter a commit message, e.g.,

Add a .gitignore file
# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
#
# On branch master
# Changes to be committed:
#       new file:   .gitignore
#

Save and exit (for emacs, Ctrl-x Ctrl-s then Ctrl-x Ctrl-c).

git status

This should output something like:

On branch master
nothing to commit, working tree clean

or

On branch master
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        Makefile
  hello.c
  hello.script
  hello.timing

nothing added to commit but untracked files present (use "git add" to track)

if you have uncommitted files.

Notice .gitignore is no longer untrack, because it was committed. But hello is also untracked, not because it was committed, but because you have asked git to ignore it.

Enter

git add hello.c
git commit hello.c

Enter an appropriate commit message.

If you encounter errors or do not know how to use the emacs editor, please be sure to complete the git exercise before proceeding. Then setup this project's git repository.

Then enter

git add hello.timing hello.script
git commit hello.timing hello.script

Enter an appropriate commit message and then do

git add Makefile
git commit Makefile

Enter an appropriate commit message and finally do (if you haven't already done this here)

git add .gitignore
git commit .gitignore

Enter an appropriate commit message.

git push

You should see something similar to this:

Enumerating objects: 14, done.
Counting objects: 100% (5/5), done.
Writing objects: 100% (3/3), 264 bytes | 264.00 KiB/s, done.
Total 13 (delta 0), reused 0 (delta 0), pack-reused 0
To eustis3.eecs.ucf.edu:cop3402/NID/hello
   0721d93..886c6f7  master -> master

If you encounter errors, be sure to complete the git exercise before proceeding. Then setup this project's git repository.

If you have already run the self-check, you can remove it like this

rm -rf ~/tmp/hello_selfcheck

Double-check the path carefully to avoid deleting the wrong directory.

git clone gitolite3@eustis3.eecs.ucf.edu:cop3402/$USER/hello ~/tmp/hello_selfcheck

You should see something like

Cloning into '/home/net/NID/tmp/hello_selfcheck'...
done.

If you see

fatal: destination path '/home/net/NID/tmp/hello_selfcheck already exists and is not an empty directory.

then remove the previous self-check.

ls -a

You should see the five required files (hello.c, hello.script, hello.timing, Makefile, .gitignore), .git, ., .., and (optionally) a README.md file, e.g.,

.
..
.git
README.md
hello.c
hello.script
hello.timing
Makefile
.gitignore

The order does not matter. If you have a README.md, that is okay. If you have hello or any other program binary, remove it with these instructions and rerun the self-check.

You can also validate what files are actually in the repo like this:

git ls-tree --full-tree -r --name-only HEAD

make

This should only create the hello program and do nothing else (not run the program either).

Running ls should show the hello program now in the directory.

./hello

This should output hello, world! on its own line, i.e.,

hello, world!

If you see a missing "\n", which will have the command-prompt immediately after the text, e.g.,

hello, world!NID:~/cop3402spring25/hello$ 

or if you see a missing comma, missing exclamation point, any capitalized letters, go back and follow the directions closely.

make clean

This should remove the hello binary. Confirm that it is gone with ls.

make
./hello

You should get the same behavior as before with make and ./hello.

scriptreplay hello.timing hello.script 2

You should see a recording of yourself opening emacs, entering the hello world program, saving, and exiting.