Shell实现的一些数学运算自定义函数分享

#!/bin/bash
############################
#重写shell中基本数学运算+ - × /
#时间:2014-01-18
#邮箱：jianye_jia@163.com
#版本: version 1.0
#备注：目前只支持2位整数运算
############################
#####################
#function is_Digit()
#判断参数是否为数字
#支持浮点数
#只能传入一个参数
#是，返回1，否则返回0
######################
functionis_Digit()
{
ref=`echo$1 |  awk'{print($0~/^[+-]?[0-9]?*(\.[0-9]*)?$/)?"digit":"string"}'`
if[ "$ref"== "digit"];then
return0;
else
return1;
fi
}
###################
#function multiply()
#判断参数是否为数字
#并将两个参数相乘
#函数直接传入引用
#变量的变量的实现${!para}
#函数的返回值，不能像C一样return，
#需要打印输出，echo
###################
functionmul()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%d \n",num_a*num_b}'`;
echo$ref;
}
########################
#function div()
#检查参数，返回两个数字差
########################
functiondiv()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%d \n",num_a/num_b}'`;
echo$ref;
}
########################
#function add()
#检查参数，返回两个数字和
########################
functionadd()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%d \n",num_a+num_b}'`;
echo$ref;
}
########################
#function sub()
#检查参数，返回两个数字差
########################
functionsub()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%d \n",num_a-num_b}'`;
echo$ref;
}
###################
#function mul_f()
#判断参数是否为数字
#并将两个参数相乘
#函数直接传入引用
#变量的变量的实现${!para}
#函数的返回值，不能像C一样return，
#需要打印输出，echo
###################
functionmul_f()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%0.2f \n",num_a*num_b}'`;
echo$ref;
}
########################
#function div_f()
#检查参数，返回两个数字差
########################
functiondiv_f()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%0.2f \n",num_a/num_b}'`;
echo$ref;
}
########################
#function add_f()
#检查参数，返回两个数字和
########################
functionadd_f()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%0.2f \n",num_a+num_b}'`;
echo$ref;
}
########################
#function sub_f()
#检查参数，返回两个数字差
########################
functionsub_f()
{
for(( i=1;i<3;i++ ))
do
pa="$i"
ifis_Digit ${!pa}
then
continue;
else
echo"$pa isn't a number";
return0;
fi
done
ref=`awk-vnum_a=$1 -vnum_b=$2 'BEGIN{printf "%0.2f \n",num_a-num_b}'`;
echo$ref;
}