Double Quotes
Double quotes stop the expansion. If you place characters inside of double quotes, all special characters used by the shell have their special meaning and are treated as ordinary characters. This means some expansions do not work in double quotes example: pathname expansion, tilde expansion, and brace expansion are suppressed.
Example:
Now you can see here that the shell does not remove any space
echo "Hi GFG" Expected Output: Hi GFG
Output
But Some expansion still works example: arithmetic expansion, and command substitution.
Bash Pathname Expansion in Linux
When you type a command and press enter, bash performs several processes upon the text before carrying out our command as a command. The process that makes this happen is called expansion. For example, suppose you use the echo command for standard output.
echo hi Output hi
If you use echo with asterisk wildcard echo will print your directory. Suppose you have two files in the current working directory. The first file name is file1.txt and file2.txt then you will use echo with asterisk wildcard then It will print your directory name.
Example:
Types of Expansion
- Pathname Expansion
- Tilde Expansion
- Arithmetic Expansion
- Brace Expansion
- Parameter Expansion
- Command Substitution