Adding lines of users TODO to motd

Question

Hello,
I've been trying to customise radu242's /etc/issue from the thread https://bbs.archlinux.org/viewtopic.php?id=50845&p=3 into a user specific motd by replacing the text in the box with some lines from the users TODO.txt.
At the moment I have a working, but not really, version that a) doesn't actually use the motd, but echo's the message from /etc/profile,  b) relies on the user keeping their TODO in a specific place, and c) has very ugly bash coding because I'm only learning.
So, in order to finish this, I need more info and was hoping someone could help:
For a)
    Is there any way to call variables directly from the /etc/motd file? - I tried $HOME but that didn't work as I expect it hasn't been initialised by then.
For b)
    I'd like to export a TODO variable before I call the message, which would have to be done very early so it's available in /etc/profile (or motd, if possible). Is there a way of adding an option into the /etc/passwd parsing? I doubt it but it would be awesome if there was, also I'd really appreciate a method of automatically updating (preferably with confirmation from the user) such an option.
For c)
    My TODO's have a specific format, the titles start at the beginning of a line and end with a  :  then the next line is the most important task in that title. In order to put these lines into my logo I need (unless anyone knows a better way) to make the titles and first line underneath into separate variables. I've done this with:
12 TODOfile="$HOME/TODO/MainTODO.txt"
13 linenos=$( grep -n -P "^[A-Z].*:$" ${TODOfile} | sed 's/:.*//' )
14 i=0
15
16 for num in $linenos;
17 do
18 newline=$( sed -n "${num}p" ${TODOfile} )
19 ret[${i}]="${newline}"
20 i=$(( i+1 ))
21 num=$(( num+1 ))
22 newline=$( sed -n "${num}p" ${TODOfile} )
23 ret[${i}]="${newline}"
25 i=$(( i+1 ))
25 done
which I think must be overly complicated (especially the repetition in the for loop), but I can't make it any better at the moment and would really appreciate some pointers.
Also, as this was an exercise to help me understand a little more about what linux does upon login, any alternate routes using files I haven't thought of are very welcome.
Thanks in advance
Apple
Last edited by Apple (2013-04-02 20:42:45)

Answer 1

Cheers, I'll give that a go when I get back to my laptop.
With the other two, yes, kinda.
I'm trying to move the message to as early in the logging in process as possible (purely for learning purposes). At the moment I call the executeable from /etc/profile before I call any bashrc, so I have some env variables but I'm looking for a way to do it earlier. From what I've found I think all env variables at that point have come from the entry in /etc/passwd, but I can't see how to add another variable in there as the syntax is odd.
I know the /etc/motd file is printed out before the /etc/profile file is called, so I think the motd file doesn't have access to any env variables. My original aim was to put the message there and there seems to be something in PAM that calls the motd. I thought if I could make the PAM call user specific I coult create a different motd for each user and echo the message into each user's file upon the previous logout, but again different syntax that I can't understand.