A framework for creating a Bash CLI application.
MIT License
A utility for creating a Bash CLI application.
$ docker run --rm -it unfor19/bargs:example --help
Help Message is auto generated, set bargs > description
to update the usage (--help
) message
Short and Long Names are supported with name=person_name
and short=n
Description Per Argument is supported with description=What is your name?
Flexible Assignment enables passing arguments with the equal sign or a whitespace
example.sh --name "Willy Wonka"
example.sh --name="Willy Wonka"
Default Value for each argument can be set with default=some-value
default
contains whitespaces, use double quotes - default="Willy Wonka"
default
starts with a $
, then it's a variabledefault=$LANG
is evaluted to default=en_US.UTF-8
Allow Environment Variables with allow_env_var=true
, if argument is empty then the environment variable will be used. If environment variable is empty, the default
will be used
export USERNAME=willywonka
$USERNAME
or $username
Allow Empty Values with allow_empty=true
Flag Argument with flag=true
, if the flag is provided, its value is true - CI=true
Constrain Values is supported with options=first second last
, use whitespace as a separator
Prompt for arguments with prompt=true
hidden=true
confirmation=true
brew install util-linux
sudo apt-get -y update && sudo apt-get install -y bsdmainutils
apk add --no-cache util-linux bash
yum update -y && yum install -y util-linux bash
Works in Windows-Subsystem-Linux (WSL) using Ubuntu 18.04
Make sure you use dos2unix on all files, see another example here
choco install dos2unix
# ...
dos2unix bargs.sh bargs_vars example.sh tests.sh
# ...
wsl -u root -d Ubuntu-18.04 -- source example.sh
Download bargs.sh
(10 kilobytes) and the bargs_vars
template
curl -sL --remote-name-all bargs.link/{bargs.sh,bargs_vars}
curl -sL --remote-name-all bargs.link/1.1.4/{bargs.sh,bargs_vars}
Reference to bargs_vars
- do one of the following
bargs.sh
and bargs_vars
are in the same folderbargs_vars
path - export BARGS_VARS_PATH="${PWD}/path/to/my_bargs_vars"
, see tests.sh
Edit bargs_vars
- Declare arguments/variables, here are some ground rules
---
is required once at the beginning, and twice in the end=
, ~
, \
, '
, "
bargs
is necessary, comments belowsource
bargs at the top of the bash script. Do not add set -o pipefail
before source bargs.sh
---
name=bargs # DON'T TOUCH!
description=bash example.sh -n Willy --gender male -a 99 # Editable, that's the usage message
default=irrelevant # DON'T TOUCH!
---
---
---
name=person_name
short=n
description=What is your name?
default="Willy Wonka"
---
name=age
short=a
description=How old are you?
prompt=true
confirmation=true
---
name=gender
short=g
description=male or female?
options=male female
prompt=true
---
name=location
short=l
description=Where do you live?
default="chocolate factory"
---
name=favorite_food
short=f
allow_empty=true
options=chocolate pizza
description=chocolate or pizza?
---
name=secret
short=s
default=!@#%^&*?/.,[]{}+-|
description=special characters
---
name=language
short=lang
default=$LANG
description=default value can be a variable
---
name=password
short=p
prompt=true
hidden=true
confirmation=true
description=What is your password?
---
name=happy
short=hp
flag=true
description=Flag for indicating that you are happy
---
name=ci
short=ci
flag=true
description=Flag for indicating it is a CI/CD process
---
name=username
short=un
allow_env_var=true
description=Username fetched from environment variable
default=willywonka
---
name=bargs
description=bash example.sh -n Willy --gender male -a 99
default=irrelevant
---
---
Add one of the following lines at the beginning of your application (see Usage below)
bargs.sh
is in the root folder of your project (just like in this repo)
source "${PWD}"/"$(dirname ${BASH_SOURCE[0]})"/bargs.sh "$@"
bargs.sh
is in a subfolder, for example tools
source "${PWD}"/"$(dirname ${BASH_SOURCE[0]})"/tools/bargs.sh "$@"
The arguments are now available as environment variables, both lowercased and UPPERCASED (see Usage below)
Using the bargs_vars
above in our application - example.sh
#!/bin/bash
source "${PWD}"/"$(dirname ${BASH_SOURCE[0]})"/bargs.sh "$@"
echo "
Name: ~ $person_name
Age: ~ $age
Gender: ~ $gender
Location: ~ $location
Favorite food: ~ $favorite_food
Secret: ~ $secret
Password: ~ $password
OS Language: ~ $language
I am happy: ~ $happy
CI Process: ~ $CI
Uppercased var names: ~ $PERSON_NAME, $AGE years old, from $LOCATION
Username from env var: ~ $username " \
| column -t -s "~"
-------------------------------------------------------
[LOG] Bargs Vars Path - Should pass
[LOG] Executing: source example.sh -a 33 --gender male -p mypassword
[LOG] Output:
Name: Oompa Looma
Age: 33
Gender: male
Location: chocolate factory
Favorite food:
Secret: !@#%^&*?/.,[]{}+-|
Password: mypassword
OS Language: C.UTF-8
I am happy:
CI Process:
Uppercased var names: Oompa Looma, 33 years old, from chocolate factory
Username from env var: runner
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] Help Menu - Should pass
[LOG] Executing: source example.sh -h
[LOG] Output:
Usage: bash example.sh -n Willy --gender male -a 99
--person_name | -n [Willy Wonka] What is your name?
--age | -a [REQUIRED] How old are you?
--gender | -g [REQUIRED] male or female?
--location | -l [chocolate factory] Where do you live?
--favorite_food | -f [] chocolate or pizza?
--secret | -s [!@#%^&*?/.,[]{}+-|] special characters
--language | -lang [C.UTF-8] default value can be a variable
--password | -p [REQUIRED] What is your password?
--happy | -hp [FLAG] Flag for indicating that you are happy
--ci | -ci [FLAG] Flag for indicating it is a CI/CD process
--username | -un [willywonka] Username fetched from environment variable
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] Default Values - Should pass
[LOG] Executing: source example.sh -a 99 --gender=male -p mypassword
[LOG] Output:
Name: Willy Wonka
Age: 99
Gender: male
Location: chocolate factory
Favorite food:
Secret: !@#%^&*?/.,[]{}+-|
Password: mypassword
OS Language: C.UTF-8
I am happy:
CI Process:
Uppercased var names: Willy Wonka, 99 years old, from chocolate factory
Username from env var: runner
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] New Values - Should pass
[LOG] Executing: source example.sh -a 23 --gender male -l=neverland -n meir -p mypassword
[LOG] Output:
Name: meir
Age: 23
Gender: male
Location: neverland
Favorite food:
Secret: !@#%^&*?/.,[]{}+-|
Password: mypassword
OS Language: C.UTF-8
I am happy:
CI Process:
Uppercased var names: meir, 23 years old, from neverland
Username from env var: runner
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] Valid Options - Should pass
[LOG] Executing: source example.sh -a 23 --gender male -l neverland -n meir -f pizza -p=mypassword
[LOG] Output:
Name: meir
Age: 23
Gender: male
Location: neverland
Favorite food: pizza
Secret: !@#%^&*?/.,[]{}+-|
Password: mypassword
OS Language: C.UTF-8
I am happy:
CI Process:
Uppercased var names: meir, 23 years old, from neverland
Username from env var: runner
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] Special Characters - Should pass
[LOG] Executing: source example.sh -a 99 --gender male -s MxTZf+6KHaAQltJWipe1oVRy -p mypassword
[LOG] Output:
Name: Willy Wonka
Age: 99
Gender: male
Location: chocolate factory
Favorite food:
Secret: MxTZf+6KHaAQltJWipe1oVRy
Password: mypassword
OS Language: C.UTF-8
I am happy:
CI Process:
Uppercased var names: Willy Wonka, 99 years old, from chocolate factory
Username from env var: runner
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] Use Flag - Should pass
[LOG] Executing: source example.sh -a 23 --gender male --happy -p mypassword -ci
[LOG] Output:
Name: Willy Wonka
Age: 23
Gender: male
Location: chocolate factory
Favorite food:
Secret: !@#%^&*?/.,[]{}+-|
Password: mypassword
OS Language: C.UTF-8
I am happy: true
CI Process: true
Uppercased var names: Willy Wonka, 23 years old, from chocolate factory
Username from env var: runner
[LOG] Test passed as expected
-------------------------------------------------------
[LOG] Empty Argument - Should fail
[LOG] Executing: source example.sh -a 99 --gender -p mypassword
[LOG] Output:
[HINT] Valid options: male OR female
[ERROR] Invalid value "-p" for the argument "gender"
Usage: bash example.sh -n Willy --gender male -a 99
--person_name | -n [Willy Wonka] What is your name?
--age | -a [REQUIRED] How old are you?
--gender | -g [REQUIRED] male or female?
--location | -l [chocolate factory] Where do you live?
--favorite_food | -f [] chocolate or pizza?
--secret | -s [!@#%^&*?/.,[]{}+-|] special characters
--language | -lang [C.UTF-8] default value can be a variable
--password | -p [REQUIRED] What is your password?
--happy | -hp [FLAG] Flag for indicating that you are happy
--ci | -ci [FLAG] Flag for indicating it is a CI/CD process
--username | -un [willywonka] Username fetched from environment variable
[LOG] Test failed as expected
-------------------------------------------------------
[LOG] Unknown Argument - Should fail
[LOG] Executing: source example.sh -a 99 -u meir -p mypassword
[LOG] Output:
[ERROR] Unknown argument "-u"
Usage: bash example.sh -n Willy --gender male -a 99
--person_name | -n [Willy Wonka] What is your name?
--age | -a [REQUIRED] How old are you?
--gender | -g [REQUIRED] male or female?
--location | -l [chocolate factory] Where do you live?
--favorite_food | -f [] chocolate or pizza?
--secret | -s [!@#%^&*?/.,[]{}+-|] special characters
--language | -lang [C.UTF-8] default value can be a variable
--password | -p [REQUIRED] What is your password?
--happy | -hp [FLAG] Flag for indicating that you are happy
--ci | -ci [FLAG] Flag for indicating it is a CI/CD process
--username | -un [willywonka] Username fetched from environment variable
[LOG] Test failed as expected
-------------------------------------------------------
[LOG] Invalid Options - Should fail
[LOG] Executing: source example.sh -a 23 --gender male -l neverland -n meir -f notgood -p mypassword
[LOG] Output:
[HINT] Valid options: chocolate OR pizza
[ERROR] Invalid value "notgood" for the argument "favorite_food"
Usage: bash example.sh -n Willy --gender male -a 99
--person_name | -n [Willy Wonka] What is your name?
--age | -a [REQUIRED] How old are you?
--gender | -g [REQUIRED] male or female?
--location | -l [chocolate factory] Where do you live?
--favorite_food | -f [] chocolate or pizza?
--secret | -s [!@#%^&*?/.,[]{}+-|] special characters
--language | -lang [C.UTF-8] default value can be a variable
--password | -p [REQUIRED] What is your password?
--happy | -hp [FLAG] Flag for indicating that you are happy
--ci | -ci [FLAG] Flag for indicating it is a CI/CD process
--username | -un [willywonka] Username fetched from environment variable
[LOG] Test failed as expected
-------------------------------------------------------
[LOG] Missing bargs_vars - Should fail
[LOG] Executing: source example.sh -h
[LOG] Output:
[ERROR] Make sure bargs_vars is in the same folder as bargs.sh
Another option - export BARGS_VARS_PATH="/path/to/my_bargs_vars"
[LOG] Test failed as expected
You can use Docker to package your Bash script as a Docker image, see the following example
Clone this repository
Build the image, see Dockerfile.example, tag it bargs:example
docker build -f Dockerfile.example -t bargs:example .
Run a container that is based on the image above
docker run --rm -it bargs:example -a 23 -g male
Thinking of writing a new Bash script? Hit the Use this template button and get a fully working example of bargs, including GitHub Actions workflows.
Report issues/questions/feature requests on the Issues section.
Pull requests are welcome! These are the steps:
git checkout -b my-new-feature
)bash tests.sh
... # All good? Move on to the next step
git commit -am 'Added new feature'
)git push --set-up-stream origin my-new-feature
)Created and maintained by Meir Gabay
This project is licensed under the MIT License - see the LICENSE file for details