There is a question to add the arguments from the script CLI and then display in the following format:
10 + 20 + 30 = 60
If the input is:
$ sum_for 10 20 30
The script that i have written is:
#!/bin/bash
sum=0
for i in $@;
do
sum=$((sum+i));
done
echo $sum
exit 0
Which just outputs the sum, instead as stated above. Can you please help me how to print the output as stated above.
You can just construct the output string on the fly, with something like:
#!/bin/bash
((sum = 0)) # I like spacing expressions :-)
text="" # Initial text
prefix="" # and term prefix.
for i in "$@" ; do # Handle each term
((sum = sum + i)) # by accumulating
text="${text}${prefix}${i}" # and adding to expression.
prefix=" + " # Adjust term prefix to suit.
done
echo "${text} = ${sum}" # Output expression and result.
This can be seen in action thusly:
pax> ./sum_for 5 6 72
5 + 6 + 72 = 83
And, if you wanted to make it relatively robust to bad input data, you could try:
#!/bin/bash
((sum = 0))
text=""
prefix=""
for i in "$@" ; do
if [[ $i =~ ^-?[0-9]+$ ]] ; then
((sum = sum + i))
text="${text}${prefix}${i}"
prefix=" + "
else
echo "WARNING, ignoring non-integer '${i}'."
fi
done
echo "${text} = ${sum}"
Showing a sample run of that with various invalid data items:
pax> ./some_for 5 6 72 x 6x x6 -3 +4 --4 ++7 -+3 +-4 "" + - 4
WARNING, ignoring non-integer 'x'.
WARNING, ignoring non-integer '6x'.
WARNING, ignoring non-integer 'x6'.
WARNING, ignoring non-integer '+4'.
WARNING, ignoring non-integer '--4'.
WARNING, ignoring non-integer '++7'.
WARNING, ignoring non-integer '-+3'.
WARNING, ignoring non-integer '+-4'.
WARNING, ignoring non-integer ''.
WARNING, ignoring non-integer '+'.
WARNING, ignoring non-integer '-'.
5 + 6 + 72 + -3 + 4 = 84
That disallows some values that you may wish to allow but I've opted for only numbers in their simplest form, like 4 instead of +4, or --4, or even ++++----+--+4 :-)
Changing what's permitted is a (relatively) simple matter of changing the regular expression filter.
You can pass all the shell arguments ,as a variable in awk and get the sum for all of them in its BEGIN section.
cat code.sh
var="$@"
awk -v value="$var" 'BEGIN{z=split(value,a," ");for(i=1;i<=z;i++){s+=a[i]};print s}'
Using printf you can do something like
#!/bin/bash
sum=0
for ((i=1; i <= $#; i++))
do
((sum += ${!i})) # sum with indirection
printf '%*.*s%d' 0 $(( i==1 ? 0 : 3)) ' + ' ${!i} # use variable width
done
printf ' = %d\n' $sum
