b update

Update binaries and sync env files. If no arguments are given, b updates all binaries and envs from the b.yaml configuration file.

Alias

• u

Usage

b update [binary|env...] [flags]

Examples

Update all binaries and envs

If a b.yaml file is present, this command will update all binaries to their latest versions and re-sync all env files.

b update

Update a specific binary

Update a single binary to its latest version.

b update jq

Force an update

Force an update even if the binary is already at the latest version. This is useful for re-installing a corrupted binary.

b update --force kubectl

Update with merge strategy

Use the --strategy flag to control how env file updates handle local changes:

# Replace local files with upstream (default)
b update --strategy=replace

# Keep local files, only add new ones
b update --strategy=client

# Three-way merge: upstream changes + local changes
b update --strategy=merge

Merge strategies

Strategy	Description
replace	Overwrite local files with upstream content (default)
client	Keep local files unchanged; only add new files from upstream
merge	Three-way merge using the lock file as a common ancestor. Detects conflicts and prompts for resolution

When using merge, b computes a three-way diff between:

1. The base version (from b.lock — last known good state)
2. The upstream version (latest from the remote repo)
3. The local version (your current file on disk)

If both upstream and local have changed the same region, a conflict marker is inserted and the user is prompted to resolve it.

Env conflict warnings

When multiple env entries write to the same destination path, b warns about potential conflicts before syncing:

⚠ Conflict: config.yaml is written by both github.com/org/infra (base/config.yaml)
  and github.com/org/overrides (override/config.yaml)
  Hint: use 'dest' or 'ignore' in b.yaml to resolve

Dry-run

Preview what would change without writing files or updating the lock:

b update --dry-run

Rollback

Revert envs to their previous commit (from b.lock):

b update --rollback github.com/org/infra

Group filtering

Only update envs tagged with a specific group:

b update --group=dev

Post-update hooks

Binaries configured with an onPost hook in b.yaml will run that hook after a successful update — the same way it runs after b install. The hook only fires when the on-disk binary actually changed (not on digest-match skips or --dry-run).

binaries:
  github.com/arg-sh/argsh:
    onPost: argsh builtin ${B_EVENT}   # B_EVENT=update

See b install — Post-install hooks for the full list of environment variables and examples.

Flags

Flag	Description
--strategy	Merge strategy for env updates: replace, client, or merge
--dry-run	Show what would change without writing files
--rollback	Rollback envs to their previous commit from lock
--group	Only update envs in this group
-h, --help	help for update

Global Flags

Flag	Description
-c, --config string	Path to configuration file (current: /home/fentas/github/fentas/b/.bin/b.yaml)
--force	Force operations, overwriting existing binaries
-q, --quiet	Quiet mode
-v, --version	Print version information and quit