您正在将从和**重定向到同一个文件。
这就是问题所在。
尝试更改您的简单命令，即：

git stripspace < myfile.txt > myfile.txt

改为：

git stripspace < myfile.txt > my-other-file.txt

它应该能正常工作。

sponge正是解决这个问题的工具，它首先“吸收”所有输入的数据，然后将其写入指定的文件，它是moreutils包的一部分-在Ubuntu上用sudo apt install moreutils安装它，
下面是一个使用文件spacetest.txt的示例-awk命令用于帮助可视化文件中存在的尾随空格：

# print the file spacetest.txt with '%' appended to each line-end to show trailing spaces

~/temp/stripspace-test$ awk '{ print $0 "%" }' spacetest.txt 
%
%
line 1 has a space at the end %
line 2 has 2 spaces at the end  %
line 3 has 3 spaces at the end   %
%
the next line has 4 spaces%
    %
three blank lines follow this one%
%
%
%

# 'redirect' from and to spacetest.txt using `sponge` as a go-between

~/temp/stripspace-test$ git stripspace < spacetest.txt | sponge  spacetest.txt

# print the file spacetest.txt again to demonstrate everything is as expected

~/temp/stripspace-test$ awk '{ print $0 "%" }' spacetest.txt 
line 1 has a space at the end%
line 2 has 2 spaces at the end%
line 3 has 3 spaces at the end%
%
the next line has 4 spaces%
%
three blank lines follow this one%