script to send an email

druuna · 09-15-2011, 11:09 AM

Hi,

Quote:

Originally Posted by doru

Yes it does.

No it doesn't ....

Using the script you posted (post #2) altered to show the content of the mountedon variable inside and outside the loop:

Code:

$ cat tets.sh
#!/bin/bash

df -Ph |awk '{ print $5 " " $1 " " $6 }' | while read outstring;
do
  percentuse=$(echo $outstring | awk '{ print $1}' | cut -d'%' -f1  )
  partition=$(echo $outstring | awk '{ print $2 }' )
  mountedon1=$(echo $outstring | awk '{ print $3 }' )

  if [[ $percentuse -ge 90 ]]; then
    mountedon=$mountedon\ $mountedon1
  fi
  echo "[IN LOOP] mountedon : $mountedon"
done
echo "[OUSIDE LOOP] mountedon : $mountedon"

$ ./tets.sh
[IN LOOP] mountedon : 
[IN LOOP] mountedon : 
[IN LOOP] mountedon :  /data/Movie
[IN LOOP] mountedon :  /data/Movie /data/Sounds
[OUSIDE LOOP] mountedon :

You need to do as shown by Reuti (post #11) :

Code:

while read outstring;
do

  ---- code goes here ----

done < <(df -Ph | awk '{ print $5 " " $1 " " $6 }')

doru · 09-18-2011, 12:29 PM

Quote:

Originally Posted by druuna

Hi,
No it doesn't ....

Using the script you posted (post #2) altered to show the content of the mountedon variable inside and outside the loop:

You are right, my script is wrong. However, the problem is not caused by any encapsulation while would offer, but by the fact that, as part of a pipeline, while is run in a subshell.

To avoid writing to disk, I would suggest this form:

Code:

#!/bin/bash

while read outstring;
do
  percentuse=$(echo $outstring | awk '{ print $1}' | cut -d'%' -f1  )
  partition=$(echo $outstring | awk '{ print $2 }' )
  mountedon1=$(echo $outstring | awk '{ print $3 }' )

  if [[ $percentuse -ge 50 ]]; then
    mountedon=$mountedon\ $mountedon1
  fi
  echo "[IN LOOP] mountedon : $mountedon"
done < <(df -Ph | awk '{ print $5 " " $1 " " $6 }')
echo "[OUSIDE LOOP] mountedon : $mountedon"

Thank you for drawing my attention to this bug.

Now I see that you posted the same solution. How can you post a solution if you don't explain the cause of the bug correctly?