1.

The expand(1) command expands tabs to sequences of space characters. Suppose you have a file named myfile.txt in your current working directory. List five different commands you could use to expand tab characters in the file myfile.txt using the expand command. The five commands must exemplify five different types or forms of commands.

For the purposes of this question, the "form or type of command" is determined by:

a. whether one (child) process is created to perform the command (this is one possibility) or two processes (children) are created to perform the command (the other possibility);

b. the presence (one possibility) or lack (the other possibility) of pipes in the command;

c. whether or not expand(1) gets its input from a file (one possibility) or from its stdin (the other possibility);

d. whether or not expand(1) is given any "[FILE]" arguments (one possibility) or not (the other possibility) when it is started within the child process.

If the set of choices to the above are different for one command than they are for another command, then those two commands are "of a different type". However, the options given to expand(1) are not used to determine the "type of command" in this question.

Also for the purposes of this question,

1.when expand(1) executes according to your command, its standard output must be (bound to) your virtual terminal (in which you are executing the command);

2.your commands cannot use command substitution, process substitution, subshells, or (the built-in command) exec, if you happen to already know what any of those are;

3.there can be only one instance of expand in the pipeline;

4.whether or not the commands execute in the foreground or background is irrelevant to this question;

5.the settings of any environment variables used by expand(1) are irrelevant to this question.

Submit a file q1_solution.txt containing your five commands. If you cannot determine five different types of commands, submit as many as you can.