The current directory is not normally included in your $PATH on a *nix operating system like OS X; to execute a program in the current directory, precede it with the path to the current directory (.):

$ ./emulator

Emulator can be added with Android Studio https://developer.android.com/studio/run/managing-avds.html

To start emulator: ~/Library/Android/sdk/tools/emulator -avd Nexus_5X_API_23

Related question: How do I launch the Android emulator from the command line?

solutions

1. Symbolic link

steps

1. create one symbolic link emulator

# soft link
$ ln -s ~/Library/Android/sdk/tools/emulator /usr/local/bin/emulator

2. call the command

# check all avd
$ emulator -list-avds

$ emulator @avd_name
# OR
$ emulator -avd avd_name

2. system environment

1. edit env with vim/vscode

# zsh
$ vim  ~/.zshrc
# OR
$ code  ~/.zshrc

2. add below lines to the .zshrc file

# export ANDROID_SDK_ROOT=/Users/xgqfrms/Library/Android/sdk

export ANDROID_SDK_ROOT=~/Library/Android/sdk
export ANDROID_HOME=~/Library/Android/sdk
export ANDROID_AVD_HOME=~/.android/avd

3. update config

# flush update
$ source ~/.zshrc

refs

https://developer.android.com/studio/run/emulator-commandline

Open Android Studio. Click on AVD Manager (the icon with the android and phone) [example image: AVD Manager]. See the list of emulators. You should see something like "Install Emulator" if you don't have any.

Once this is successful, you'll get the tools folder downloaded to your ~/Library/Android/sdk

That is the folder you want, because it has the android and emulator command line tools.