此脚本在MinGW-64中运行完美，但在Ubuntu中失败

awk: /home/username/chuleta/chuleta/glst.awk: line 22: illegal reference to variable a

awk: /home/username/chuleta/chuleta/glst.awk: line 23: illegal reference to variable a

...甚至在将shebang从#!/usr/bin/gawk -f更改为#!/usr/bin/awk -f以放弃GNU Awk和非GNU Awk之间的实现差异之后。

#!/usr/bin/awk -f

# generates list of terms related to a topic

# this funcion substitutes a with b in $0
func change(a,b) {
    while (i=index($0,a))
            $0 = substr($0,1,i-1) b substr($0,i+length(a))
}

{
    # we delete the base folder (received in var RTO) from the input line
    # and clean it of other stuff
    change(RTO,"")
    change(".txt","")
    change("/"," ")
    change("_"," ")
    split($0,a," ")
    # using arr as associative array by using same string as index
    # this prevents duplicated strings and code is shorter
    # since we don't have to maintain a counter for index
    for (x in a)  # this is line 22
        arr[a[x]]=a[x] # this is line 23
}

END{
    n=asort(arr,sarr)
    for (x in sarr)
        printf("%s ",sarr[x])
}

变量a应该是使用空格分隔$0而得到的数组。
如前所述，这个错误在WinGW-64（Git for Windows使用的Linux bash模拟）中不会发生。
编辑：
通过Awk脚本传输的示例数据集如下所示：

/home/username/chuleta/chuleta-data/java/8/chuleta_foreach_loop.txt
/home/username/chuleta/chuleta-data/java/8/chuleta_basic_functional_interfaces_in_function_package.txt
/home/username/chuleta/chuleta-data/java/8/chuleta_advantages_new_date_time_api.txt
/home/username/chuleta/chuleta-data/java/8/chuleta_new_date_time_api.txt
/home/username/chuleta/chuleta-data/java/8/chuleta_solve_interface_default_methods_conflict.txt
/home/username/chuleta/chuleta-data/java/8/chuleta_lambdas_with_parameters.txt

RTO传递给保存基本目录的脚本（home/username/chuleta/chuleta-data/），然后从开头移除它，然后移除". txt"，将"/"和"-"更改为空格，然后将得到的空格分隔单词列表拆分为数组（"a"），它稍后被用来填充一个关联数组。基本上，我们得到一个空格分隔的子文件夹名称列表，不包括基本目录，例如"java 8 chuleta foreach循环"。产生的a数组包含这五项。遍历a的那些代码行只在Ubuntu中失败，而在MinGW-64中不会失败。
编辑2：
在Ubuntu 22.04、awk版本mawk 1.3.4 20200120、GNU bash版本5.1.16中的输出：

$ cat data.txt | ./program.awk -v RTO=/home/username/chuleta/chuleta-data
awk: ./prueba.sh: line 18: illegal reference to variable a
awk: ./prueba.sh: line 22: illegal reference to variable a
awk: ./prueba.sh: line 23: illegal reference to variable a
awk: ./prueba.sh: line 23: illegal reference to variable a

输出格式为MINGW64_NT-10.0 - 19044 3.1.7 - 340，awk版本GNU awk 5.0.0，API：2.0，GNU bash，版本4.4.23：

$ cat data.txt | ./program.awk -v RTO=/home/username/chuleta/chuleta-data
8 advantages api basic chuleta conflict date default foreach function functional in interface interfaces java lambdas loop methods new package parameters solve time with