I have following line in my script, ${snap[@]} array contain my ssh server list.
while IFS= read -r con; do
ssh foo@"$con" /bin/bash <<- EOF
echo "Current server is $con"
EOF
done <<< "${snap[@]}"
I want to print current iteration value of the array as the ssh ran successfully, the $con should print current ssh server --> example@server. How would I do that ?
If the elements in snap are the hosts that you want to connect to, just use a for loop:
for con in "${snap[@]}"; do
# connect to "$con"
done
"${snap[@]}" expands to the safely-quoted list of elements in the array snap, suitable for use with for.
If you really want to use while, then you can do something like this:
i=0
while [ $i -lt ${#snap[@]} ]; do # while i is less than the length of the array
# connect to "${snap[i]}"
i=$(( i + 1 )) # increment i
done
But as you can see, it's more awkward than the for-based approach.
for loops can do this, but I'm looking a while solution, thanks.
for, but I have added an option using while anyway.
while loop when the for loop is clearly called for?set; you can just use a while loop to produce increasing values of i that can be used to index snap.Like this :
while IFS= read -r con; do
ssh "foo@$con" /bin/bash <<EOF
echo "Current server is $con"
EOF
done < <(printf '%s\n' "${snap[@]}")
# ____
# ^
# |
# bash process substitution < <( )
Or simply :
for server in "${snap[@]}"; do
ssh "foo@$con" /bin/bash <<EOF
echo "Current server is $con"
EOF
done
printf and a while read loop to iterate over the contents of an array.
for loop version