C language: Implement a new alias command

Add a new built-in alias command that allows you to define a shortcut for
commands by essentially defining a new command that substitutes a given
string for some command, perhaps with various flags/options. The syntax is
as follows: alias alias_name=’command’. For example, you can define
an alias with alias ll=’ls –al’, so that the user can then enter ll at the
prompt to execute the ls -al command. Although there is an alias
command in bash, you must implement your own version and not make use
of the built-in alias bash command. Typically, alias is a built-in command,
but since this affects how your shell functions (i.e., you simply cannot just
pass an aliased command to the exec family system call as you are
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managing the execution which would otherwise result in a not found
message.
Specifying alias with no arguments should display a list of all existing aliases.
You may remove a single alias with the command alias -r alias_name
or all defined aliases with alias -c. Be sure to handle the case if a user enters
the alias command incorrectly. You can perform a manalias for help in
understanding how this built-in command is used, but only the functionality
specified here is required.