git-cli/README.md

git-cli

A small command-line-like Git interface for Racket. The package invokes the installed git executable and exposes commands both through the generic git procedure and through direct procedures.

(require git-cli)

(git 'status)
(git 'log '-l '-5)
(git 'fetch '--prune)
(git 'switch "main")
(git 'tag "v0.3.16")
(git 'diff)
(git 'show 'HEAD)

(git-status)
(git-fetch '--prune)
(git-switch "main")
(git-tag "v0.3.16")

git is an ordinary procedure. The first argument is the Git command symbol and the remaining arguments are passed to that command.

Several commands provide Racket-oriented output in addition to the normal Git behavior:

• git-status uses Git's porcelain status and returns structured status items.
• git-log -l / git-log --list returns (commit subject) items.
• git-tag -l / git-tag --list returns tag names; with -n it returns (tag subject) items and -n<number> supports multiple content lines.
• git-diff renders HTML by default; --output=- selects stdout and --output=string returns a string.
• git-show renders a commit and its diff as HTML by default. -l / --list provides structured variants for --stat, --name-only, and --name-status.

Git is searched on PATH. Git itself remains responsible for remotes, credentials, SSH keys, pull strategy, and other repository configuration.

Commands

The package currently registers commands including status, add, commit, push, pull, fetch, config, branch, switch, clone, tag, log, rev-list, diff, show, grep, help, version, and new-version.

Most are also exported as direct procedures such as git-status, git-add, git-fetch, git-config, git-switch, git-tag, git-log, git-diff, and git-show.

See the Scribble documentation for command-specific behavior and return values.

Git configuration

git config has a small Racket-oriented interface:

(git 'config '--all)
(git 'config 'get '--all)
(git 'config '--global 'get '--all)
(git 'config 'get '--global "user.email")
(git 'config 'get '--all "credential.helper")
(git 'config 'get "credential.helper")
(git 'config 'set! "user.email" "hans@example.invalid")
(git 'config '--global 'set! "user.email" "hans@example.invalid")
(git 'config 'set! '--global "user.email" "hans@example.invalid")

get --all without a key returns (key value) items. get --all key returns all values for one key. get key returns one string or #f when the key is absent. set! returns #t after a successful write.

Low-level Git execution

run-git can be used when direct access to Git's stdin/stdout protocol is needed. Optional text can be supplied to Git with #:input.

(run-git '(credential fill)
         #:input "protocol=https\nhost=git.dijkewijk.nl\n\n")

The result remains two values: Git's exit code and the ordered (source line) output items.

Authentication retry

Authentication failures are detected centrally after run-git, before command-specific result processing. current-git-authentication-handler defaults to default-git-authentication-handler.

The default handler first uses an existing Git credential.helper. When no helper is configured, it asks for username and password/token with input-prompt, configures the non-persistent cache helper locally, approves the credential through git credential approve, and retries the original Git command once.

A custom handler can still be installed:

(current-git-authentication-handler
 (λ (cmd args e)
   ;; Perform custom credential handling.
   #t))