Command-line completion

You can enable command-line completion (also known as tab-completion) in Bash and Zsh. This lets you tab-complete command names, flags names and flag values, and target names.

Bash

Bazel comes with a Bash completion script.

If you installed Bazel:

From the APT repository, then you’re done – the Bash completion script is already installed in /etc/bash_completion.d.
From Homebrew, then you’re done – the Bash completion script is already installed in $(brew --prefix)/etc/bash_completion.d.
From the installer downloaded from GitHub, then:
1. Locate the absolute path of the completion file. The installer copied it to the bin directory.
  
  Example: if you ran the installer with --user, this will be $HOME/.bazel/bin. If you ran the installer as root, this will be /usr/local/lib/bazel/bin.
2. Do one of the following:
  - Either copy this file to your completion directory (if you have one).
    
    Example: on Ubuntu this is the /etc/bash_completion.d directory.
  - Or source the completion file from Bash’s RC file.
    
    Add a line similar to the one below to your ~/.bashrc (on Ubuntu) or ~/.bash_profile (on macOS), using the path to your completion file’s absolute path:
    source /path/to/bazel-complete.bash
Via bootstrapping, then:
1. Build the completion script:
```
bazel build //scripts:bazel-complete.bash
```
2. The completion file is built under bazel-bin/scripts/bazel-complete.bash.
  
  Do one of the following:
  - Either copy this file to your completion directory (if you have one).
    
    Example: on Ubuntu this is the /etc/bash_completion.d directory
  - Or copy it somewhere on your local disk, e.g. to $HOME, and source the completion file from Bash’s RC file.
    
    Add a line similar to the one below to your ~/.bashrc (on Ubuntu) or ~/.bash_profile (on macOS), using the path to your completion file’s absolute path:
    source /path/to/bazel-complete.bash

Zsh

Bazel comes with a Zsh completion script.

If you installed Bazel:

From the APT repository, then you’re done – the Zsh completion script is already installed in /usr/share/zsh/vendor-completions.
From Homebrew, then you’re done – the Zsh completion script is already installed in $(brew --prefix)/share/zsh/site-functions.
From the installer downloaded from GitHub, then:
1. Locate the absolute path of the completion file. The installer copied it to the bin directory.
  
  Example: if you ran the installer with --user, this will be $HOME/.bazel/bin. If you ran the installer as root, this will be /usr/local/lib/bazel/bin.
2. Add this script to a directory on your $fpath:
```
fpath[1,0]=~/.zsh/completion/
mkdir -p ~/.zsh/completion/
cp /path/from/above/step/_bazel ~/.zsh/completion
```
  You may have to call rm -f ~/.zcompdump; compinit the first time to make it work.
3. Optionally, add the following to your .zshrc.
```
# This way the completion script does not have to parse Bazel's options
# repeatedly.  The directory in cache-path must be created manually.
zstyle ':completion:*' use-cache on
zstyle ':completion:*' cache-path ~/.zsh/cache
```