source

Execute a script in the current shell context (no subshell).

low risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
What it does

source (or its synonym `.`) runs a script in the current shell rather than a subshell — so variables, functions, and aliases defined in the script persist after it finishes. Essential for applying changes to ~/.bashrc without restarting the terminal.

Examples
source ~/.bashrcReload bash config without restarting terminal · explain & risk-check →
source .envLoad environment variables from a .env file · explain & risk-check →
. /etc/profile.d/custom.shSource using POSIX dot syntax · explain & risk-check →
source <(kubectl completion bash)Load kubectl tab completion · explain & risk-check →
Pro tip

Use `source .env` in dev workflows — keep secrets in .env (gitignored) and load them on demand rather than exporting globally.

Related
export alias bash
Open the full explainer →More in Shell & Scripting

Reference text is hand-written and may be incomplete — check man source for your version. Test destructive commands on a non-production system first.