What is the function of the Logical AND operator (&&) in a Dockerfile?

What is the function of the Logical AND operator (&&) in a Dockerfile?

• A. To run multiple commands in sequence, only if the previous command is successful
• B. To chain commands without error handling
• C. To separate commands in the same RUN line
• D. To create a pipeline between processes

Answer: (A)

In a Dockerfile, the RUN instruction executes commands in a shell, and the logical AND operator makes the next command run only if the previous one finished successfully. This provides simple error handling during the image build: if any step fails, the rest of the commands in that RUN line won’t run, so you don’t end up building with a broken state. A common pattern is RUN apt-get update && apt-get install -y curl && rm -rf /var/lib/apt/lists/* to ensure the subsequent steps only proceed when each prior step succeeded. By comparison, using a semicolon would run subsequent commands regardless of failures, and a pipe is used to connect outputs between processes, not to enforce conditional execution.

In a Dockerfile, the RUN instruction executes commands in a shell, and the logical AND operator makes the next command run only if the previous one finished successfully. This provides simple error handling during the image build: if any step fails, the rest of the commands in that RUN line won’t run, so you don’t end up building with a broken state. A common pattern is RUN apt-get update && apt-get install -y curl && rm -rf /var/lib/apt/lists/* to ensure the subsequent steps only proceed when each prior step succeeded. By comparison, using a semicolon would run subsequent commands regardless of failures, and a pipe is used to connect outputs between processes, not to enforce conditional execution.