How to open a new file in a another tab instead of a new window in Atom editor?

Solution 1:

Is there is a way to tell atom (via a config or something) not open a new window?

atom -n false /path/to/new_file.txt

Where:

-n, --new-window Open a new window. [boolean]

Source Open file/project from terminal / command line - features - Atom Discussion:

atom --help
Atom Editor v0.80.0

Usage: atom [options] [file …]

Options:
-d, --dev Run in development mode. [boolean]
-f, --foreground Keep the browser process in the foreground. [boolean]
-h, --help Print this usage message. [boolean]
-l, --log-file Log all output to file. [string]
-n, --new-window Open a new window. [boolean]
-s, --spec-directory Set the spec directory (default: Atom’s spec directory). [string]
-t, --test Run the specified specs and exit with error code on failures. [boolean]
-v, --version Print the version. [boolean]
-w, --wait Wait for window to be closed before returning. [boolean]

Does atom have rc file or global config so I can set this option as default there?

Atom loads configuration settings from the config.cson file in your %USERPROFILE%\.atom directory.

However the --new-window option is not one of the configurable options.

Source Basic Customization