3.5 KiB
Hello World
The classical introductory exercise. Just say "Hello, World!".
"Hello, World!" is the traditional first program for beginning programming in a new language or environment.
The objectives are simple:
- Write a function that returns the string "Hello, World!".
- Run the test suite and make sure that it succeeds.
- Submit your solution and check it at the website.
If everything goes well, you will be ready to fetch your first real exercise.
Welcome to Bash!
Unlike many other languages here, bash is a bit of a special snowflake. If you are on a Mac or other unix-y platform, you almost definitely already have bash. In fact, anything you type into the terminal is likely going through bash.
The downside to this is that there isn't much of a development ecosystem around bash like there is for other languages, and there are multiple versions of bash that can be frustratingly incompatible. Luckily we shouldn't hit those differences for these basic examples, and if you can get the tests to pass on your machine, we are doing great.
Installation
As mentioned above, if you are on a unix-like OS (Mac OS X, Linux, Solaris, etc), you probably already have bash.
Testing
As there isn't much of a bash ecosystem, there also isn't really a de facto leader in the bash testing area. For these examples we are using bats. You should be able to install it from your favorite package manager, on OS X with homebrew this would look something like this:
$ brew install bats
==> Downloading
https://github.com/bats-core/bats-core/archive/v1.2.0.tar.gz
==> Downloading from
https://codeload.github.com/bats-core/bats-core/tar.gz/v1.2.0
########################################################################
100.0%
==> ./install.sh /opt/boxen/homebrew/Cellar/bats/1.2.0
🍺 /opt/boxen/homebrew/Cellar/bats/1.2.0: 10 files, 60K, built in 2
seconds
Run the tests with:
bats hello_world_test.sh
After the first test(s) pass, continue by commenting out or removing the
[[ $BATS_RUN_SKIPPED == true ]] || skip
annotations prepending other tests.
To run all tests, including the ones with skip
annotations, run:
BATS_RUN_SKIPPED=true bats hello_world_test.sh
Source
This is an exercise to introduce users to using Exercism http://en.wikipedia.org/wiki/%22Hello,_world!%22_program
External utilities
Bash
is a language to write "scripts" -- programs that can call
external tools, such as
sed
,
awk
,
date
and even programs written in other programming languages,
like Python
.
This track does not restrict the usage of these utilities, and as long
as your solution is portable between systems and does not require
installation of third party applications, feel free to use them to solve
the exercise.
For an extra challenge, if you would like to have a better understanding
of the language, try to re-implement the solution in pure Bash
,
without using any external tools. Note that there are some types of
problems that bash cannot solve, such as performing floating point
arithmetic and manipulating dates: for those, you must call out to an
external tool.
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.