Learner Reference

Last updated on 2024-03-12 | Edit this page

Quick reference

pwd
print working directory
ls
list directory :
  • -l: list file information
  • -lh: list human readable file information
cd
change directory
mkdir
make directory
cat
send file or files to output (in most cases, print to shell)
head
output first parts of a file or files
tail
output last parts of a file or files
mv
rename or move a file or files. Syntax for renaming a file: mv FILENAME NEWFILENAME
cp
copy a file or files. Syntax: cp FILENAME NEWFILENAME
>
redirect output. Syntax with cat: cat FILENAME1 FILENAME2 > NEWFILENAME
rm
remove a file or files. NB: USE WITH CAUTION!!!

Git commands

git init
create a new local git repository
git status
view the status of your files in the working directory and staging area
git add
tell git to start tracking a file, or a series of files
git commit
save file changes from the staging area permanently to the project history
git push
upload all commits to a remote repository, such as GitHub
git log
show history of commits in reverse chronological order
git diff
show changes made to tracked files
git pull
download upstream changes and merge them into your local repository
git remote add origin
add a remote repository named ‘origin’, to upload changes to or download changes from

Glossary

changeset
A group of changes to one or more files that are or will be added to a single commit in a version control repository.
commit
To record the current state of a set of files (a changeset) in a version control repository. As a noun, the result of committing, i.e. a recorded changeset in a repository. If a commit contains changes to multiple files, all of the changes are recorded together.
conflict
A change made by one user of a version control system that is incompatible with changes made by other users. Helping users resolve conflicts is one of version control’s major tasks.
HTTP
The Hypertext Transfer Protocol used for sharing web pages and other data on the World Wide Web.
merge
(a repository): To reconcile two sets of changes to a repository.
protocol
A set of rules that define how one computer communicates with another. Common protocols on the Internet include HTTP and SSH.
remote
(of a repository) A version control repository connected to another, in such way that both can be kept in sync exchanging commits.
repository
A storage area where a version control system stores the full history of commits of a project and information about who changed what, when.
resolve
To eliminate the conflicts between two or more incompatible changes to a file or set of files being managed by a version control system.
revision
A synonym for commit.
SHA-1
SHA-1 hashes is what Git uses to compute identifiers, including for commits. To compute these, Git uses not only the actual change of a commit, but also its metadata (such as date, author, message), including the identifiers of all commits of preceding changes. This makes Git commit IDs virtually unique. I.e., the likelihood that two commits made independently, even of the same change, receive the same ID is exceedingly small.
SSH
The Secure Shell protocol used for secure communication between computers.
timestamp
A record of when a particular event occurred.
version control
A tool for managing changes to a set of files. Each set of changes creates a new commit of the files; the version control system allows users to recover old commits reliably, and helps manage conflicting changes made by different users.