10 Tips for Writing Efficient Bash Scripts
Bash is the default command line interface for many Linux distributions and a powerful scripting language. Here are some suggestions that will keep your Bash scripts efficient and lean.
1. Avoid Full Paths to Bash Builtins
Bash has many builtins that can be used instead of calling external commands. You should leverage the builtin commands whenever possible since it avoids calling a subcommand from the system.
Since Bash has builtins for some commands found in /bin and /usr/bin (such as echo), avoid using the full path for these commands and the builtin will be used.
# avoid this
Use the Bash builtin instead:
Other bash builtins include: test, read, declare, eval, let pushd and popd. See the Bash man page for a full listing of builtins.
2. Avoid External Commands for Integer Math