Question

我正在尝试编写一个脚本，允许用户输入文件名并显示文件中的行数，字数，字符数或全部数，具体取决于用户是否输入'l' （行），'w'（字），'c'（字符）或'a'（全部）。

这是我到目前为止所拥有的：

#!/bin/sh                                                                                                                         

# Prompt for filename                                                                                                             
read -p 'Enter the file name: ' filename

# Prompt which of lines, words, or chars to display                                                                               
read -p 'Count lines, words, characters, or all three (l, w, c, a)? ' display
while [ $display -ne "l" -o $display -ne "w" -o $display -ne "c" -o $display -ne "a" ]
do
    echo "Invalid option"
    read -p 'Count lines, words, characters, or all three (l, w, c, a)? ' display
done

# Display to stdout number of lines, words, or chars                                                                              
set `wc $filename`
if [ $display -eq "l" ]
then
    echo "File '$4' contains $1 lines."
elif [ $display -eq "w" ]
then
    echo "File '$4' contains $2 words."
elif [ $display -eq "c" ]
then
    echo "File '$4' contains $3 characters."
else
    echo "File '$4' contains $1 lines, $2 words, and $3 characters."
fi

如果我运行脚本并提供名为trial.txt的文件并选择选项w，我会得到输出：

./icount: 11: [: Illegal number: w
./icount: 19: [: Illegal number: w
./icount: 22: [: Illegal number: w
./icount: 25: [: Illegal number: w
File 'trial.txt' contains 3 lines, 19 words, and 154 characters.

有人可以帮我解释这个错误吗？

Answer 1

我明白了。 -eq和-ne是整数比较运算符。比较字符串时，您必须使用=和!=。

Answer 2

此外，您应该在while循环中使用AND conditions

#!/bin/sh                                                                                                                         

# Prompt for filename                                                                                                             
read -p 'Enter the file name: ' filename

# Prompt which of lines, words, or chars to display                                                                               
read -p 'Count lines, words, characters, or all three (l, w, c, a)? ' display
while [ "$display" != "l" -a "$display" !=  "w" -a "$display" != "c" -a "$display" != "a" ]
do
    echo "Invalid option"
    read -p 'Count lines, words, characters, or all three (l, w, c, a)? ' display
done

# Display to stdout number of lines, words, or chars                                                                              

set `wc $filename`
if [ $display == "l" ]
then
    echo "File '$4' contains $1 lines."
elif [ $display == "w" ]
then
    echo "File '$4' contains $2 words."
elif [ $display == "c" ]
then
    echo "File '$4' contains $3 characters."
else
    echo "File '$4' contains $1 lines, $2 words, and $3 characters."
fi

如何将用户定义的变量与字符串文字进行比较

2 个答案: