Here's a great account of the good, nerdy thoughtfulness that went into generating the command-line screenshots for Tron: Legacy; JT Nimoy decided that he'd go for a mix of l33t and realistic, and landed on emacs eshell and posix kill:

In addition to visual effects, I was asked to record myself using a unix terminal doing technologically feasible things. I took extra care in babysitting the elements through to final composite to ensure that the content would not be artistically altered beyond that feasibility. I take representing digital culture in film very seriously in lieu of having grown up in a world of very badly researched user interface greeble. I cringed during the part in Hackers (1995) when a screen saver with extruded "equations" is used to signify that the hacker has reached some sort of neural flow or ambiguous destination. I cringed for Swordfish and Jurassic Park as well. I cheered when Trinity in The Matrix used nmap and ssh (and so did you). Then I cringed again when I saw that inevitably, Hollywood had decided that nmap was the thing to use for all its hacker scenes (see Bourne Ultimatum, Die Hard 4, Girl with Dragon Tattoo, The Listening, 13: Game of Death, Battle Royale, Broken Saints, and on and on). In Tron, the hacker was not supposed to be snooping around on a network; he was supposed to kill a process. So we went with posix kill and also had him pipe ps into grep. I also ended up using emacs eshell to make the terminal more l33t. The team was delighted to see my emacs performance — splitting the editor into nested panes and running different modes. I was tickled that I got emacs into a block buster movie. I actually do use emacs irl, and although I do not subscribe to alt.religion.emacs, I think that's all incredibly relevant to the world of Tron.