使用 bash 增加 .txt 文件中的变量

Question

I'm trying to change a variable in a .txt file but I can't figure how. I've looked on internet and tried what was written but it doesn't work. I get the following error message :

sed: 1: "abc.txt": command a expects \\ followed by text

Here was what I originally tried to run:

sed -i 's/Hi/Good Morning/' abc.txt

Answer 1

Check your man page for sed. -i probably requires a suffix argument.

-i extension

Edit files in-place, saving backups with the specified extension. If a zero-length extension is given, no backup will be saved. It is not recommended to give a zero-length extension when in-place editing files, as you risk corruption or partial content in situations where disk space is exhausted, etc.

What's happening is that sed is taking 's/Hi/Good Morning/' to be the argument to -i , and then considering abc.txt to be the sed command itself.

By adding a proper backup extension to the command, it will work like so:

$ cat abc.txt
Hi, How are you

$ sed -i .bak 's/Hi/Good Morning/' abc.txt

$ cat abc.txt
Good Morning, How are you

$ cat abc.txt.bak
Hi, How are you