Subtracting values from variable

Legends,

Please help me in , how do i subtract the variable values listed like below.
the first value of orig should be subtracted from first value of prev and so on.

san> echo $orig
346 316 340 239 410 107 291 139 128 230 167 147 159 159 172 116 110 260 177 0 177 169 168 186 165 366 195 131 7 143 60 276 149 114 120 110 103 5 0 87 79 104 101 142 184 13 278 2 153 160 0 5 101 127 151 14 196 138 90 177 195 166 135 122 136 117 169 518 244 125 116 127 117 131 129 121 120 164 218 105 111 122 127 123 117 168 536 192 177 133 130 160 78 126 678 277 294 297 842 78

san> echo $prev
346 316 340 239 410 107 291 139 128 230 166 147 159 159 172 116 110 260 177 0 177 167 168 186 165 366 195 131 7 143 60 276 145 114 120 110 103 5 0 87 79 101 99 140 184 13 278 2 153 160 0 5 99 125 150 14 196 136 87 177 195 162 135 121 136 113 169 518 244 125 116 127 117 131 129 119 117 164 218 101 111 122 127 123 116 168 536 192 177 133 130 160 78 126 678 277 294 297 842 78

Pls help

try something like this..

assuming both variables have same number of fields..

echo "" | awk -v FV="$orig" -v SV="$prev" '{ n=split(FV,F);split(SV,S)}END{
for(i=1;i<=n;i++){printf (S - F)" "}}' 

I am not able to use just awk..

any guess?

i Tried the follwoing using array but no go

for (( i = 0 ; i < ${#orig[@]} ; i++ ))
do
for (( j = 0 ; j < ${#prev[@]} ; j++ ))
do
if [ $i == $j ];
then
(( DIFF = ${orig} - ${prev[j]} ))
echo $DIFF;
else
echo ${orig}  ${prev[j]} > /dev/null 2>&1
fi
done
done

---------- Post updated at 04:51 AM ---------- Previous update was at 04:48 AM ----------

@pamu

below is the error i am gettng

> echo "" | awk -v FV="$orig" -v SV="$prev" '{ n=split(FV,F);split(SV,S)}END{for(i=1;i<=n;i++){printf (F - S)" "}}'
awk: syntax error near line 2
awk: bailing out near line 2

try using nawk

In ksh93/bash (assuming that there are equal number of elements in both variables):

orig_array=($orig)
prev_array=($prev)
diff=
for((i=0;i<${#orig_array[*]};i++))
do
 diff="$diff $(( ${prev_array} - ${orig_array} ))"
done

echo $diff

producing

0 0 0 0 0 0 0 0 0 0 -1 0 0 0 0 0 0 0 0 0 0 -2 0 0 0 0 0 0 0 0 0 0 -4 0 0 0 0 0 0 0 0 -3 -2 -2 0 0 0 0 0 0 0 0 -2 -2 -1 0 0 -2 -3 0 0 -4 0 -1 0 -4 0 0 0 0 0 0 0 0 0 -2 -3 0 0 -4 0 0 0 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

@elixir,
main requirement is: i have two files File A and File B
using these two files, i want out with difference to third one (say file C) after calculating diff from 3rd column from file
using "bash" shell

file A
abc             xxx  340 
def             yyy  239 
ghi             zzz  410 

file B
abc             xxx  330 
def             yyy  230 
ghi             zzz  310 

OUTPUT SHOLUD be

File C
abc             xxx  10 times diff
def             yyy  9 times diff
so on... 

There is a big difference between how you handle files and variables. You mention variables in one post (and in the thread title) and files in the other.

Please don't try to oversimplify the problem. This makes it difficult to provide a proper solution.

initially i tried to get the values in variable , later realized, by "paste" command we can get the values in 3rd file. so tried that option.

try this..

awk 'FNR==NR{a[$1,$2]=$3;next}{if(a[$1,$2]){print $1,$2,(a[$1,$2]-$3)" times diff"}}' OFS="\t" file1 file2

if it doesn't work try using nawk

pamu.
Thanks, it is working. just i need to take care of other characters like

"blank lines and "========= HOSTNAME ========" etc

Could you please provide your input files containing those..
Because i don't think it will print blank lines and '========= HOSTNAME ========"

the file contains like below both files have similar entries file A and file B

=================== DIFF Report on abc host at 10/12 12:21 ==================
abc             xxx  340 
def             yyy  239 
ghi             zzz  410 

=================== DIFF Report on def host at 10/12 12:21 ==================
jkl             xxx  340 
mno             yyy  239 
pqr             zzz  410 

=================== DIFF Report on def host at 10/12 12:21 ==================
...
...
...

awk 'FNR==NR{a[$1,$2]=$3;next}{if(a[$1,$2] && $1 !~ "==="){print $1,$2,(a[$1,$2]-$3)" times diff"}}' OFS="\t" file1 file2

This is exactly working as i wanted except i missed hostnames now.
anything can be done on not to eliminate hostnames

abc             xxx  1 times diff 
def             yyy  1 times diff
ghi             zzz  1 times diff
jkl             xxx  1 times diff
mno             yyy  1 times diff
pqr             zzz  1 times diff

Where you want hostnames..? and where are the hostnames in the input.?

Please give your desired output...

Actually i modified the filename to get the second column as hostname. so all done.

Thanks for your nawk. it made my day