Datadriven shell编程？建议，请

Question

我想将我的shell脚本转换为使用datadriven方法。但是由于在任何shell中都没有“表格”类型的值（我知道），有什么建议替代方法来做到这一点？

我正在寻找的是解决方案，将允许人们做这样的事情：

animals = [['horse', 300 'brown'], 
      ['cat', 3, 'black'], 
      ['elephant', 3000, 'grey'], 
      ['mouse', 0.3, 'grey']] 
for a in animals ; do 
    echo "A typical $a[1] is $a[3] and weighs about $a[2] kilograms." 
done 

更确切地说，我想尝试一些命令，看看其中的一个是可用的，然后发送参数：

commands = [['c1', '-m', '-i'], 
      ['c2', '-message', '-icon'], 
      ['c3', '/m', '/i']] 
for c in commands ; do 
    if exists c[1] ; then 
    command = c[1] 
    message_option = c[2] 
    icon_option = c[3] 
    break; 
    fi 
done 
$command $message_option "message" $icon_option icon 

Answer 1

没有bashisms需要。

#!/bin/sh 
while read animal weigth colour; do 
    printf '%s\n' "A typical $animal is $colour and weighs about $weight kilos." 
done << EOF 
horse 300 brown 
cat 3 black 
elephant 3000 grey 
mouse 0.3 grey 
EOF 

观察如何按名称引用的元素与1，不神秘的索引，2，3，它不叉：这可以用这里文档由while read循环中读取被干净利落地解决了/ exec任何外部命令并击败另一个答案中看到的循环体中的3个awk。

Answer 2

试试这个吗？

cat file 
'horse', 300, 'brown' 
'cat', 3, 'black' 
'elephant', 3000, 'grey' 
'mouse', 0.3, 'grey' 

for i in {1..4} ; 
do 
    animal=$(awk -F, -v var="$i" 'NR== var {print $1}' file) 
    weight=$(awk -F, -v var="$i" 'NR== var {print $2}' file) 
    colour=$(awk -F, -v var="$i" 'NR== var {print $3}' file) 
    echo "A typical "$animal" is "$colour" and weighs about "$weight" kilos." 
done 

输出 -

A typical 'horse' is 'brown' and weighs about 300 kilos. 
A typical 'cat' is 'black' and weighs about 3 kilos. 
A typical 'elephant' is 'grey' and weighs about 3000 kilos. 
A typical 'mouse' is 'grey' and weighs about 0.3 kilos. 

Answer 3

您可以定义和bash使用associative-arrays您的需求。

#!/bin/bash 

# declaring the Associative array 
declare -a animals 

animals[0]="'horse':300:'brown'" 
animals[1]="'cat':3:'black'" 
animals[2]="'elephant':3000:'grey'" 
animals[3]="'mouse':0.3:'grey'" 

for animal in "${animals[@]}" 
do 
    myArray=(${animal//:/ }) 
    printf "A typical "${myArray[0]}" is "${myArray[2]}" and weighs about "${myArray[1]}" kilograms.\n" 
done 

在上述唯一棘手的部分是类型的parameter-expansion

${parameter/pattern/string} 
      The pattern is expanded to produce a pattern just as in filename expansion. Parameter is expanded and the longest match of pattern against its value is replaced with string. 
If pattern begins with ‘/’, all matches of pattern are replaced with string. Normally only the first match is replaced. 

所以理想的是串'horse':300:'brown'被分割为各个元件和存储其随后用于访问各个元件阵列myArray在一个C风格的循环。