Number of shell statistic features

Today is too lazy, do not want a characteristic of a feature to statistics, and write a script

#!/bin/bashdir_bas=$ (CD $ (dirname ${0});p wd) a= ' cat $dir _bas/feat ' feat_bas=$1total=0for B in $Ado    echo $B    Count= ' grep ' $B ' $feat _bas | Wc-l '    echo $count    ((total= $count + $total)) Doneecho "Total feat num is $total"

Statistics number that's a pit, I forgot the shell requirements for space strict Ah,

' Expr $count + $total '

Script operations

1, two numbers added

Variable 1= ' expr $ variable 2 + $ variable 3 '
Variable 1= ' expr $ variable 2 + constant '

2, two number subtraction

Variable 1= ' expr $ variable 2-$ variable 3 '
Variable 1= ' expr $ variable 2-constant

3, two number multiplication

Variable 1= ' expr $ variable 2 \* $ variable 3 '
Variable 1= ' expr $ variable 2 \* constant '

Divide 4 and two numbers

Variable 1= ' expr $ variable 2/$ variable 3 '
Variable 1= ' expr $ variable 2/constant '

Number of shell statistic features