你如何在BASH中将csv文件读入二维数组？

How do you read a csv file into a two dimensional array in BASH? The script needs to be dynamic enough where it can take csv files with variable number of rows and columns.

你如何在BASH中将csv文件读入二维数组？该脚本需要足够动态，它可以使csv文件具有可变数量的行和列。

For example, if I have a csv file that looks like

例如，如果我有一个看起来像的csv文件

AVERAGE     STDEV     MAX
17          18        19

要么

AVERAGE     STDEV     MAX     MIN
17          18        19      1

2 个解决方案

#1

One way to simulate a two-dimensional array is to keep the rows as strings in a one-dimensional array and unpack them at each iteration. You will have to choose a suitable delimiter that doesn't appear in the data. Since you mention CSV, I'll use a comma, but this won't be smart enough to handle data like this with embedded commas:

模拟二维数组的一种方法是将行保存为一维数组中的字符串，并在每次迭代时解压缩它们。您必须选择一个未出现在数据中的合适分隔符。既然你提到了CSV，我会使用一个逗号，但是这对于使用嵌入式逗号来处理这样的数据是不够智能的：

name, start date, visits, games, balance
"Williamson, Dennis", "January 11, 2007", 12, 42, 17000

Here's a simple example of iterating over the values in a simulated two-dimensional array:

这是一个迭代模拟二维数组中的值的简单示例：

# avg, stddev, max, min
data_array=(
            "17,18,19,1"
            "12,14,16,2"
            "6,8,10,3"
            )

saveIFS=$IFS

for row in ${data_array[@]}
do
    IFS=","
    cols=($row)
    IFS=$saveIFS
    for col in ${cols[@]}
    do
        newval=$(do_something $col)
    done
done

Making changes to the contents of the array is possible:

可以更改数组的内容：

rowidx=2
colidx=2
IFS=","
cols=(${data_array[rowidx]})
cols[colidx]=$some_value
data_array[rowidx]="${cols[*]}"
IFS=$saveIFS

As you can see, it gets complicated fast and there are lots of gotchas which I haven't mentioned. Use Python.

正如你所看到的那样，它很快变得复杂，并且有很多我没有提到过的问题。使用Python。

#2

bash supports only one-dimensional arrays. To see an emulation of 2 dimensions check out twodim.sh in the advanced bash scripting guide:

bash仅支持一维数组。要查看2维的模拟，请查看高级bash脚本编制指南中的twodim.sh：

example 27.17 in

例子27.17 in

http://tldp.org/LDP/abs/html/arrays.html

And I agree this does sound like homework.

我同意这听起来像家庭作业。

#1

name, start date, visits, games, balance
"Williamson, Dennis", "January 11, 2007", 12, 42, 17000