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Output breaking when returning multiple values

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# 1  
Old 01-18-2013
Output breaking when returning multiple values
I've been trying to write a command-line function to grab a website's MX records and their ip addresses. The code below works with domains that only have one MX record:

Code:
function kmx { mx=`host -t MX $1 | awk '{ print $7 }'`; 
ip=`host $mx | sed '/IPv6/d;/handled/d' | awk '{ print $4 }'`; 
kdialog --title "KMX" --msgbox "# host -t MX $1
$mx     $ip";}; kmx clone-ozone.com

However, changing the function parameter at the end to google.com or a domain with multiple MX Records breaks the output of the ip addresses.

Tried messing with some arrays and different things to try to get around this but kept getting syntax errors:

Code:
function kmx { mx+=`host -t MX $1 | awk '{ print $7 }'`; 
ip=for i in "${mx[@]}"; do host ${mx[$i]} | sed '/IPv6/d;/handled/d' | awk '{ print $4 }'; done; 
kdialog --title "KMX" --msgbox "# host -t MX $1
bash: syntax error near unexpected token `do'

Perhaps I'm just too tired, but any suggestions would be appreciated.

*Side note, kdialog is KDE only but removing that part should make it runnable from the cli.
Last edited by Azrael; 01-20-2013 at 09:22 AM..
# 2  
Old 01-19-2013
Something like this should work, but it will print only the first name and IP if multiple servers are configured.
If you want them all, you should use ${mxs[@]} ${ips[@]}, instead of ${mxs[0]} ${ips[0]}.
kdialog seem to truncate the text though.

Code:
kmx() {
  mxs=( $( host -t MX "$1" | awk '{ sub(/\.$/, x, $NF); print $NF }' ) )
  ips=( $( for _mx in "${mxs[@]}"; do host "$_mx" | awk '/has address/ { print $NF }'; done ) )
  kdialog --title "KMX" --msgbox "# host -t MX $1 ${mxs[0]} ${ips[0]}"  

}

This User Gave Thanks to radoulov For This Post:
Azrael
# 3  
Old 01-20-2013
Thank you Radoulov

Kdialog seems to be able to handle the output when given all the specific array elements:

Code:
kmx() {   mxs=( $( host -t MX "$1" | awk '{ sub(/\.$/, x, $NF); print $NF }' ) );   
ips=( $( for _mx in "${mxs[@]}"; do host "$_mx" | awk '/has address/ { print $NF }'; done ) );   
kdialog --title "KMX" --msgbox "# host -t MX $1 
${mxs[0]} ${ips[0]}
${mxs[1]} ${ips[1]}
${mxs[2]} ${ips[2]}
${mxs[3]} ${ips[3]}
${mxs[4]} ${ips[4]}
"  ; }; kmx google.com

Not sure, but I've found that kdialog is white-space specific. Perhaps it broke the output before because it was trying to write a whole array to one line. However, if that was the case it seems it would have not printed all the MX Records with this:

Code:
$ function kmx { mx=`host -t MX $1 | awk '{ print $7 }'`; 
ip=`host $mx | sed '/IPv6/d;/handled/d' | awk '{ print $4 }'`; 
kdialog --title "KMX" --msgbox "# host -t MX $1
$mx $ip";}; kmx google.com

Grant you that breaks the ips, but the $mx should have broken too if that was the case.

I know I could check the length of the array in this function, but I don't know if writing a loop to call each of these elements with kdialog would be possible or not. However, without the code being able to determine the number of MX Records and ip addresses itself would kind of defeat the purpose.

Any further suggestions appreciated.
# 4  
Old 01-20-2013
As I already said, if you want all the array values,
you'll need:

Code:
"# host -t MX $1 ${mx[@]} ${ip[@]}"

Not sure how kdialog will handle all those values.
# 5  
Old 01-20-2013
I did try using "@" to display all the array contents. However, as you suggested that didn't work. That's why I eluded to the use of white space.

It appears my last attempt will work for my purposes, but I would like to understand how to display a full array's contents with kdialog.

Thanks again,
# 6  
Old 01-21-2013
This should work with bash, zsh and ksh93:

Code:
kmx() {
  mxs=( $( host -t MX "$1" | awk '{ sub(/\.$/, x, $NF); print $NF }' ) )
  ips=( $( for _mx in "${mxs[@]}"; do host "$_mx" | awk '/has address/ { print $NF }'; done ) )
  msg=$(
    for ((i = -1; i++ < ${#mxs[@]} - 1;)); do
      printf '%s\t%s\n' "${mxs[i]}" "${ips[i]}"
    done  
    )
  kdialog --title "KMX" --msgbox "# host -t MX $1:
$msg"  
}

Last edited by radoulov; 01-21-2013 at 09:32 AM.. Reason: Corrected.
This User Gave Thanks to radoulov For This Post:
Azrael
# 7  
Old 01-21-2013
You would think so, but this only seems to return $1 and no mx or ips:

Code:
kmx() {   mxs=( $( host -t MX "$1" | awk '{ sub(/\.$/, x, $NF); print $NF }' ) );   
ips=( $( for _mx in "${mxs[@]}"; do host "$_mx" | awk '/has address/ { print $NF }'; done ) );   
msg=$(
    for ((i = -1; i++ < ${#a[@]} - 1;)); do
      printf '%s\t%s\n' "${mxs[i]}" "${ips[i]}"
    done  
    );   kdialog --title "KMX" --msgbox "# host -t MX $1:
$msg"  ; }; kmx google.com

Good effort on your part though. Just starting to think kdialog may not be all its cracked up to be. Shame as I like the look of it over over APIs bash can use. Perhaps I should research others. Thank you again though.
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