Git Immersion Labs

These are the labs for the Git Immersion training, a series of self-paced exercises that take you through the basics of using git.

Online

You can find the labs online at https://gitimmersion.com.

Building the Labs

The labs are generated from a single source file that describes each of the labs. The generation is done in two steps.

Before running the labs, make sure you have the following alias in your .gitconfig file. The hist command is used extensively throughout the tutorial.

[alias]
  hist = log --pretty=format:'%h %ad | %s%d [%an]' --graph --date=short

First, the rake run command runs through each of the labs and executes the listed commands and captures the output. The auto directory is used for the automatic running and the output is captured in the samples directory.

Second, the rake labs command generates the HTML labs using the text from the src/labs.txt file and the captured live output from the samples directory. Template files for the main index, the lab pages, and the navigation divs can be found in the templates directory.

The HTML output is put into git_tutorial/html. Browsing the git_tutorial/html/index.html file will bring up the git tutorial in your browser.

Publishing the Labs

To publish the labs on the web-site, run the rake publish command. This will copy the git_tutorial/html directory to the gh-pages branch. The gh-pages branch is then pushed, which auto-publishes it from github.

Manually modifying the files in the gh-pages branch is probably the wrong thing to do. Modify the appropriate template or css file on the main branch, then run rake publish.

Lab Format Directives

The labs.txt file contains all the lab text, formatted as a text file with additional directives interpreted for both run time (generating the sample output) and format time (generating the HTML).

The Format Directives are:

h1. <lab name>

Starts a new lab with the name <lab name>. Each lab

Example:

h1. Using Revert

pre(<class name>).

A section of predefined code, using the HTML class of <class name>. The predefined code block runs until a blank line.

Example:

pre(instructions).
git log --pretty=oneline --max-count=2
git log --pretty=oneline --since='5 minutes ago'
git log --pretty=oneline --until='5 minutes ago'

The instructions class is used to format command similar to the execute section, but without executing the commands in the run phase.

p. <text...>

A paragraph of text. The text for the paragraph will continue on following lines until a blank line.

Example:

p. If you have never used git before, you need to do some setup
first.  Run the following commands so that git knows your name and
email.  If you have git already setup, you can skip down to the
line ending section.

Execute:

Execute the following shell command until a blank line is encountered. Commands are executed as they appear with the following exceptions.

• +<command line>

  Run this <command> line silently, do not include it on the lab output.

• -<command line>

  Do not run this <command line>, but include it in the lab output.

• =<sample_name>

For example, the following will execute the git status command and capture its output in the status sample for the lab. The first git commit is ignored at runtime (but will be included in lab output). The second git commit with a commit message will be executed (but will not appear in the lab output). However, the output of the second command is captured in a sample.

Execute:
git status
=status
-git commit
+git commit -m 'Using ARGV'
=commit

File: <filename>

Format the following lines (until an "EOF" string is encountered) as the contents of a file name <filename>.

Example:

File: hello.rb
# This is the hello world program in Ruby.

puts "Hello, World!"
EOF

Output:

Format the following line. (until an "EOF" string is encountered) as the output of commands.

Output lines starting with = are used to grab the sample files generated during the run phase.

Example:

Output:
git commit
Waiting for Emacs...
[main 569aa96] Using ARGV
 1 files changed, 1 insertions(+), 1 deletions(-)
EOF

Often sample lines are included in the output. Assuming you have captured the output of a status command and a commit command, you might use the following:

Output:
=status
=commit
EOF

Set: <keyword>=<ruby expression>

Evaluate the <ruby expression> and set the <keyword> to that value. Often used to grab dynamic data from the run phase for use in later commands.

For example, the following will grab the git hash value for the commit labeled "First Commit", and store it in <hash>. When the git checkout command is executed, it uses the value of <hash> in the command.

Set: hash=hash_for("First Commit")
Execute:
git checkout <hash>

=<sample name>

Define/use a sample output.

Sample output are generated during the run phase of building the Git Immersion labs. They are the output of a single command line in the Execute section of a lab.

Example:

Execute:
git checkout main
=checkout
git status
=status

The two sample lines above capture the output from the checkout and status git commands respectively. The sample output is saved (in the samples directory) until the HTML generation phase is performed.

During HTML generation, the sample lines may be "played back" by including them in the Output section of a lab.

Example:

Output:
=checkout
=status
EOF

Sample names must be unique within a single lab, but do not have to be unique across the entire project.

License

GitImmersion is released under a Creative Commons, Attribution-NonCommercial-ShareAlike, Version 3.0 License.