Bash Scripting Basics: From One-Liners to Real Scripts
Bash scripts start as one-liners you keep retyping. Here is how to grow them into reliable scripts without overengineering. Every bash script I have written started as a command I typed more than three times in a week. The leap from a one-liner to a saved script is small, and it pays back fast. The mistake I see beginners make is jumping straight to complex scripts with functions and argument parsing before they need them. Here is the path I recommend, building up only when the script demands it. Start With a Shebang and set -e The first line of any script is the shebang, which tells the system what interpreter to use. For bash I use #!/usr/bin/env bash because it respects the user's environment. The second addition I make to almost every script is set -euo pipefail . The -e flag exits on the first error, -u treats unset variables as errors, and pipefail makes a pipeline fail if any command in it fails. Without these, a script can silently continue after an error and produce misleading results. #!/usr/bin/env bash set -euo pipefail echo 'Starting backup' cp -r…