1. Command to change your password?

   passwd

2. Command to return to your home directory?

   cd
   cd ~

3. 'cp' commands to do the following:
 a) Copy the file 'foo' as 'bar':

   cp foo bar

 b) Make a copy of the directory 'dir1' and _all its contents_ as 'dir2':

   cp -r dir1 dir2

 c) Copy all the files _in the current directory_ to the directory '~/.trash/':

   cp -r . ~/.trash/

 d) Copy a directory "foo" to "bar" preserving all the meta-information about
    the files:

   cp -a foo bar

4. How would you use "scp" to copy the directory "foo" to the home
   directory of "user" on the machine "host.indstate.edu"?

   scp -r foo user@host.indstate.edu:

5. How would you rename the file "foo" to "bar"?

   mv foo bar

6. "ls" command to list ALL the contents of a directory in long format,
   sorted in reverse by last modification time?

   ls -a -l -r -t   or  ls -alrt

7. How would you use "mkdir", in a single invocation, to make the
   sub-directory path "a/b/c" _in your home directory_?

   mkdir -p ~/a/b/c

8. "chmod" commands to do the following (assume filename is 'foo'):
 a) Make a file readable only by the owner and with no permissions for anyone
    else:

    chmod u=r,go= foo
    chmod 400 foo

 b) Make sure that a file is readable by everyone, but w/o modifying the other
    permissions, whatever they may be:

    chmod a+r foo

 c) Make the file readable and writable by the user, readable by the group
    and no permissions for other:

    chmod u=rw,g=r,o= foo
    chmod 640 foo

 d) Make the file fully accessible by the user, no permissions for the group
    and readable by other:

   chmod u=rwx,g=,o=r foo
   chmod 704 foo