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Bash Script: Difference betweem single ( ' ) and double quotes ( " )

The Bash manual has this to say:

Single Quotes
Enclosing characters in single quotes (‘'’) preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash.

Double Quotes
Enclosing characters in double quotes (‘"’) preserves the literal value of all characters within the quotes, with the exception of ‘$’, ‘`’, ‘\’, and, when history expansion is enabled, ‘!’. The characters ‘$’ and ‘`’ retain their special meaning within double quotes (see Shell Expansions). The backslash retains its special meaning only when followed by one of the following characters: ‘$’, ‘`’, ‘"’, ‘\’, or newline. Within double quotes, backslashes that are followed by one of these characters are removed. Backslashes preceding characters without a special meaning are left unmodified. A double quote may be quoted within double quotes by preceding it with a backslash. If enabled, history expansion will be performed unless an ‘!’ appearing in double quotes is escaped using a backslash. The backslash preceding the ‘!’ is not removed.

The special parameters ‘*’ and ‘@’ have special meaning when in double quotes (see Shell Parameter Expansion).

Below is a simple bash script which explains the difference between single and double quotes:
Source: cat


# Using single quotes, preserves the literal value of all characters within the quotes.
echo 'This is example of $single quotes from $linuxpoison'

# Using double quotes, the value of $ is expanded.
echo "This is example of $double quotes from $linuxpoison"

Output: ./
This is example of $single quotes from $linuxpoison
This is example of  quotes from blog


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