Guideline for all solutions in Gnu-linux-shell-use.

As one core characteristic of Gnu-linux-shell-use is reusability, each solution adheres to the following rules:

• Use a standard approach.
• Provide documentation.
• Do not contain deprecated or old-styled code.
• Use portable syntax whene possible (some current solutions still have to be updated).
• Include a source if one exists.
• Do not depend on another solution.

In adherence to the principle of simplicity, all solutions also adhere to the following rules:

• Do not alter any system files.
• Output data only to
  ${HOME}/.computingfoundation/gnu-linux-shell-use[--packaged-solutions]/<solution_name[-additional_part]>/.

• Spaces are used for all whitespace (tabs are allowed for Bash Here documents only).
• An indent is 2 spaces.

• Single quotes are used when possible.

• An argument variable (e.g. ${1}) is used directly rather than being assigned to a new variable when possible.
• A variable in an arithmetic expression is called without brackets (e.g. $((numEntries - count)), not $((${numEntries} - ${count}))).

• POSIX is used over extended Bash syntax (e.g. single bracket instead of double bracket conditionals) when possible.
• A case block is used when matching 3 or more values.
• A parameter expansion is quoted unless required otherwise.
• A command substitution is quoted unless required otherwise.

• A variable does not use brackets (e.g. $var, not ${var}) except when it makes sense to (e.g. in regular expressions and large scopes).

• A variable inside a string value is simply appended to the string and the entire string is quoted with double quotes rather than using explicit concatenation.

• Parentheses are used when calling user-defined functions.