*I am a newb in unix. But i need to understand this code given by client :(. i tried to ask the client details about the code like what the code is supposed to do but he himself has no idea. So basically i am stuck with a code whose purpose i do not know but i have to understand what it does >.<.
This is what i have been able to make out of the code so far( in the form of comments) [1] [2] [3] etc..
I have doubts/no clue for comments number [8] to [12] . for [1] to [7] i feel most are right, but if any are wrong feel free to point out. 
A little background : I am supposed to working in teradata and this might be related to it.
My comments are in bold{*\*}

```
#!/usr/bin/ksh  **//[1] sets shell**        
set -x     **//[2]will this show the argument values before execution?**

l=$1       **//[3]$1,$2,$3 are the arguments with which this shell**
h=$2       **//is invoked.l= first argument h= second argument and**
k=$3       **//k=3rd argument.**

/export/home/someguy/daily_refresh/abc_mt_dt.ksh $l $h $k 
           **//[4] calling abc_mt_dt.ksh
             // with arguments l h and k**   

chmod 777 /export/home/someguy/daily_refresh/$k.txt 
           **// making $k.txt a read write n**
           **//executable.This im sure im right** 

while read line
   do
      echo $line |read a b c 
          **// [5] reads three values from keyboard and displays them as     
            //well as storing them in values a b and c**

      DATA_START_DT=$a 
          **// [6] variables DATA_START_DT DATA_END_DT ID set to the three** 
      DATA_END_DT=$b   **// values read from keyboard** 
      ID=$c

      echo $DATA_START_DT **//[7] displaying the values read from keyboard**
      echo $DATA_END_DT
      echo $ID

      rm -rf /export/home/someguy/daily_refresh/logs/abc_$DATA_END_DT.log 

      **//[8] rm -rf is to recursively remove files and folders .. 
          so what will this command do? will it remove all files and folders
          inside /export/home/someguy/daily_refresh/logs/ ?**

      bteq <<EOI > /export/home/someguy/daily_refresh/logs/abc_$DATA_END_DT.log 2>&1 

      **// [9] need explaination as to what this does.**
      .run file = /export/home/someguy/logon_caracal.bteq **//[10]**
      .MAXERROR 1; **//[11]**  
       DATABASE SOME_DATABASE; **//[12]**

```