The Concept Of Quotation In Bash VS Posh

The aim of this page📝is to note the difference in single VS double quotes in bash and posh (PowerShell) which articulates a general concept of quotation.

Basically, the question is how should a machine answer the question say $your_name

• In single quotes, it says $your_name - it is repeating the symbol without evaluation
• In double quotes, it says pavol - it is evaluating the symbol and returning its meaning
• SICP covers this at this point — https://youtu.be/X21cKVtGvYk?t=1098

1. identical use of quotes

• with single quotes, variables/symbols are not evaluated, and instead their names are treated as literals

▶ $your_name="pavol"
▶ echo '$your_name'
$your_name
▶ echo "$your_name"
pavol

• same for bash

>>> read -p "Your note:" note
Your note:f.o.o.b.a.r
>>> echo '$note'
$note
>>> echo "$note"
f.o.o.b.a.r

2. different escape signs

• if you want to print single quotes as literals themselves you have to escape them
• they are special characters, not literals for the interpreter
• here is a difference
• in posh, you escape with a backtick

▶ echo `'$your_name`'
'pavol'

• in bash, you escape with a backslash

>>> your_name=pavol
>>> echo \'$your_name\'
'pavol'