Why does su cause my script to return "not found" -- 250 points

When I include su in the script below (see line 6) it ceases to return data.  Instead, it returns 'not found' for every line in the driver file (homelist.$$).  homelist contains a list of home directories across over 20 servers.  My intention is to run the script as root, have it su to each user listed in the driver file, automount the user's home directory, and grab data from some application log files.

When I run the script as me, it does exactly what I expect but is unable to access those homes where the user has restricted access.  When I run this as root and include the su command the script does not behave well.  

250 points.



v_rundir=`pwd`
 
 cat $v_rundir/homelist.3968 | while read v_home
   do
     echo "the current user account is $v_home"
     su  $v_home
     if [ -d /home/$v_home/.graphon/session-logs ]
     then
          v_log=`ls -tr /home/$v_home/.graphon/session-logs/goglobal*.* | tail -1 | cut -d/ -f6`
          echo ====================================================================
          echo "the log file is $v_log"
          v_build=`(grep "client build" /home/$v_home/.graphon/session-logs/$v_log)`
          v_build=`echo $v_build |awk '{split($0,FIELD, " "); print FIELD[4] } ' `
          echo "the build is: $v_build"
          echo "user: $v_home  build: $v_build"
          echo ====================================================================
        
        
          #------------------------------------------------------------------------
          #Now, appent to the final report
          #------------------------------------------------------------------------
        
          echo "user: $v_home      build: $v_build" >> $v_rundir/ggversions.$v_month-$v_day-$v_time
 
          #------------------------------------------------------------------------
          #Now, remove the listing of home directories; it is no longer needed.
          #------------------------------------------------------------------------
        
                   
    else  echo "Not a graphon user"
            
    fi
   
   done
jrtanenbAsked:
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TintinCommented:
The 'su' forks another process.

What you need is a 'su $v_home -c [command to run]'

Where 'command to run' is a script containing the automount and copy stuff you want to do as the user.

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TopaceCommented:
You might be able to just use sudo as well.

i.e.:

sudo 'command to execute'

This will essentially prompt you for the password ONCE, then sudo will save it for a little while (I think it's like 5 minutes), and during that time, you won't be asked for the password again.

~ace
TintinCommented:
With the recent versions of sudo, you can use the NOPASSWD directive if you don't want users to type in a password.
jrtanenbAuthor Commented:
Thank you both (Topace, Tintin) !!!

I love having the resource to get advice from people who are a lot more informed (or maybe just more intelligent) than I.  

I am going to give sudo a whirl, also.  
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