使用bash和sed的数字总和

Posted 2021-02-26

Sum of digits using bash and sed

#!/bin/sh
#Sum of all digits in a number
 
num=12334
tot=0
mod=0
echo "Number = $num"
while [ $num -gt 0 ]
   do
      mod=$(expr $num % 10)
      tot=$(expr $tot + $mod)
      num=$(expr $num / 10)
   done
echo "Sum= $tot"
 
$ ./sumofdig.sh
Number = 12334
Sum= 13
 
Another alternative using sed: 
 
$ expr $(echo "12334" | sed -e 's/[0-9]/ + &/g' -e 's/^ +//g')
13
 
Breakdown steps: 
 
$ echo "12334"
12334
 
$ echo "12334" | sed 's/[0-9]/ + &/g'
 + 1 + 2 + 3 + 3 + 4
 
$ echo "12334" | sed -e 's/[0-9]/ + &/g' -e 's/^ +//g'
 1 + 2 + 3 + 3 + 4
 
$ expr $(echo "12334" | sed -e 's/[0-9]/ + &/g' -e 's/^ +//g')
13