Note See formatted documentation at http://wizcorp.github.com/Banalize

Name

Banalize - static code analyzer for Bash

Version

Description

Banalizer is syntax analyzer for bash scripts. It is modelled after ideas of Perl::Critic static analyzer for Perl. Most of the Banalizer is written in Ruby. Exception is policy files which are language agnostic, and can be written in any language: scripting or compiled.

Banalizer consists of main binary file, banalyzer libraries, command line interface (CLI) and policies.

Policy is requirement for bash script/file. For example: each script must have 'shebang' as first line.

Each policy is implemented as Ruby or other programming/scripting language file able to perform single check on single bash script file. Rest - aggregating checks, reporting, filtering etc - is handled by Banalizer.

Severity

From Perl::Critic page:

severity is the level of importance you wish to assign to the Policy. All Policy modules are defined with a default severity value ranging from 1 (least severe) to 5 (most severe). However, you may disagree with the default severity and choose to give it a higher or lower severity, based on your own coding philosophy. You can set the severity to an integer from 1 to 5, or use one of the equivalent names:

 SEVERITY NAME ...is equivalent to... SEVERITY NUMBER
 ----------------------------------------------------
 gentle                                             5
 stern                                              4
 harsh                                              3
 cruel                                              2
 brutal                                             1

Policy style

Banalizer's policy style more or less correspond to Perl::Critic's policy theme with exclusion of Perl specific themes. Again quote from Perl::Critic:

   THEME             DESCRIPTION
   --------------------------------------------------------------------------
   core              All policies that ship with Perl::Critic
   pbp               Policies that come directly from "Perl Best Practices"
   bugs              Policies that that prevent or reveal bugs
   maintenance       Policies that affect the long-term health of the code
   cosmetic          Policies that only have a superficial effect
   complexity        Policies that specificaly relate to code complexity
   security          Policies that relate to security issues
   tests             Policies that are specific to test scripts

See http://perlcritic.tigris.org/#THE%20POLICIES

Conventions

Policies

• All policies (policy files) installed in ./lib/policies and users home ~/.banalize/policies directories.

• There are two classes of policies recognized by Banalizer: Ruby and 'other'

• Ruby policy files detected by .rb extension. Files without .rb extension are considered to be 'others'

• Policy name is detected from

  • file name of 'other' policy
  • first argument for banalizer method for Ruby policy

• all names should be unique, or they will be overwritten

Attributes

All policies have these attributes:

• policy (i.e. name)
• synopsis
• description
• severity
• style

Depending on the type of policy some of the attributes are required, some optional or can be set to reasonable default.

Non-ruby policies (i.e. others)

Policy should conform to few rules:

1. it must return information about itself when called with parameter config

   • Output of the config command is YAML formatted text
   • Command returns attributes names and values of the policy
   • All attributes in case of 'other' policy are optional

   They are either set to default values if missing, or detected from other meta-data (like, for example, name of a policy is $(basename file) of policy file.

2. Policy script must be able to perform single (syntax/semantic/format) check on bash script file and:

   • return non-zero status if check fails or 0 if succeeds
   • return (optional) error massages on STDOUT

   Note: Only STDOUT is honored by Banalizer.

   If your check command, for example, prints to STDERR but not to STDOUT, you'd need to redirect shell streams accordingly.

Example config section

    ---
    name: $(basename $0)
    style: 
      - :bug
      - :test
    severity: 5
    description: Runs bash syntax check using 'bash -n' option

Ruby policy

1. Ruby policy has two required items:
   • name (Note: to avoid clashes with Ruby standard name method we use policy DSL method)
   • must define method called run
2. Policy is defined in top-level namespace's method called banalizer
   • name is string or Ruby symbol parameter to banalizer method
   • additional (optional) attributes are defined as DSL methods calls inside block given to banalizer method
   • run method is defined in the same block
3. DSL methods names correspond to policy attributes :
   • policy (i.e. policy name)
   • synopsis
   • description
   • style
   • severity
4. run method :
   • need to return result of a check as something that can be evaluated into true or false
   • optionally can pass along error messages from the check, using errors.add DSL method to populate errors object (instance of Banalize::Errors class
5. Additionally Ruby policies have DSL method default. It sets default values for variables, that can be overridden by personal style configuration file ( See CONFIGURATION).

Examples

This is full working example of Ruby DSL policy:

banalizer :shebang_format do

  synopsis    'Format of shebang should be #!/usr/bin/env bash'
  severity    5

  def run
    unless shebang.has?(%r{\#!/usr/bin/env\s+bash})

      errors.add "First line is not in the format #!/usr/bin/env bash", 1
      return false
    end
  end

end

If you want to use filename of Ruby policy as its name, do this:

banalizer File.basename(__FILE__, '.rb').to_sym do

end