在shell脚本中求和

Question

为什么我不能在这个脚本中创建总单词的总和？我得到的结果如下:

 120+130

但它不是250(正如我所料)!有什么缘故吗？

#!/bin/bash

while [ -z "$count" ] ;
do
    echo -e "request :: please enter file name "
    echo -e "\n\tfile one : \c"
    read count

    itself=counter.sh

    countWords=`wc -w $count |cut -d ' ' -f 1`
    countLines=`wc -l $count |cut -d ' ' -f 1`
    countWords_=`wc -w $itself |cut -d ' ' -f 1`

    echo "Number of lines: " $countLines
    echo "Number of words: " $countWords
    echo "Number of words -script: " $countWords_

    echo "Number of words -total " $countWords+$countWords_  

done

if [ ! -e $count ] ; then
    echo -e "error :: file one $count doesn't exist. can't proceed."
    read empty
    exit 1
fi

Answer 1

echo"单词数量 - 总数"$ countWords + $ countWords_

你要这个:

echo "Number of words -total $((countWords + countWords_))"

编辑

以下是对脚本的一些优化.

1. 该while自循环似乎毫无意义count将会被置为确保内使之成为一个1迭代while循环.
2. 您if对文件的存在检查应该发生你曾经使用该文件之前.
3. 您不需要将脚本的名称硬编码到变量itself,您可以使用$0它
4. 由于您正在使用bash我冒昧地删除了cut使用进程替换的需要.

这是修改后的脚本:

#!/bin/bash

echo -e "request :: please enter file name "
echo -e "\n\tfile one : \c"
read count

if [ ! -e "$count" ] ; then
    echo "error :: file one $count doesn't exist. can't proceed."
    exit 1
fi

itself="$0"

read countWords _ < <(wc -w $count)
read countLines _ < <(wc -l $count)
read countWords_ _ < <(wc -w $itself)

echo "Number of lines: '$countLines'"
echo "Number of words: '$countWords'"
echo "Number of words -script: '$countWords_'"

echo "Number of words -total $((countWords + countWords_))"