Edit existing content with powershell

Question

I know it's a silly google question, but I didn't find something really simple for my need.

I have a .txt file with the following content:

hostname [ip] 
exec /bin/bash

Now, every time when I execute a certain PS script(from RUN) I want that [ip] will be changed according to my $args[0]

For example:

.txt now:

hostname 1.1.1.1 
exec /bin/bash

I am executing from run script 2.2.2.2

.txt expected:

hostname 2.2.2.2
exec /bin/bash

Note! The whole content will be always the same, only [ip] changes.

I am looking for the most simple replace solution, thanks :)

Answer 1

Your question is quite broad, and I don't want to write a whole script, so I will just answer the main part of it.

To replace "[ip]" in a file with "1.1.1.1":

gc input_file.txt | % { $_ -replace '\[ip\]', '1.1.1.1' } | sc output_file.txt

If you want to overwrite the original file, you need to put parentheses around the first statement so that it loads the entire file into memory at the beginning:

(gc my_file.txt) | % { $_ -replace '\[ip\]', '1.1.1.1' } | sc my_file.txt

gc is short for Get-Content, sc is Set-Content, and % is ForEach-Object.