linux programming problem

Use tr to modify some text so that all uppercase characters are replaced with lowercase characters. You might consider that tr can read from standard input and most versions CANNOT read text directly from files. Maybe redirection? And again, some means just that, whatever I want to give it.

Given some text, use sort to rearrange the text so that the lines are sorted numerically, from largest to smallest, using positions 2-6 (starting from the beginning of the line). The columns are NOT delimited by anything. I mean by that, positions on a line of the file where the character at the left margin is column 1, the next character (without any space) is column 2 and so on. This is not the same as having columns separated by spaces, tabs, commas, etc. Read carefully Note that if you are sorting numerically, any line whose key does NOT contain an initial number is printed before all the lines that do have a numeric key. Those nonmatching lines are printed in an arbitrary order, but it will probably be as they are encountered. In the normal numeric sort (no fields, no largest to smallest) matching lines are printed in numeric order with either the -n or -g switches. That means given

090

24sldkj

that 090 would be printed AFTER 24sldkj. This means that the entire number is considered and leading 0s are ignored.

3.Given some text, display only the third column of data, sorted (alphabetically) in ascending order. Suppress duplicate values. The columns in this one are comma separated. You will use cut and then sort for this one. Again, use a pipe.

Please provide the commands in one line with explanation.