How to write the result of the command in a text file?

 git ls-tree -r master --name-only > test.txt 

As with any other command that writes to stdout . And as with any such command, you can do a pipe-train, if you want to somehow handle the output stream.

 git ls-tree -r master --name-only | grep "some/path" | head 42 > test.txt 

Here we take only the files lying in some/path , and then leave the first 42 of them.

this design:

 $ echo $(git ...) 

somewhat "overloaded."

conditionally it can be represented as:

 $ программа $(команда) 

First, a команда is executed that is enclosed within the “shell” (from the word shell , shell) operator $() .

then its output (no matter if it contains one line or more) is converted to one line (line characters are replaced with spaces) to pass to the программе as a set of parameters (not options!).

that's why it comes out "all in one line."

in this particular case, such a conversion can be avoided quite simply - it is enough to remove echo and the $() operator - as unnecessary:

 $ команда 

but there can be such a situation as the program and the operator are needed, but it is required that there should be no “one-line conversion”. to avoid this is also not difficult - it is enough to put (double) quotes “in the way” between executing the $() operator and forming the parameter string for the программы . like that:

 $ программа "$(команда)"