I can able to select multiple lines using Esc+A. After this, what shortcut(s) should I use to comment/uncomment the selected lines?
Esc3 will comment or uncomment the selected lines in the
nano editor. The default comment character used is
# (valid in many scripting languages).
The comment character may be modified by the
comment option in your
~/.nanorc file. This is from the manual:
Use the given string for commenting and uncommenting lines. If the string contains a vertical bar or pipe character (
|), this designates bracket-style comments; for example,
"/*|*/"for CSS files. The characters before the pipe are prepended to the line and the characters after the pipe are appended at the end of the line. If no pipe character is present, the full string is prepended; for example,
"#"for Python files. If empty double quotes are specified, the comment/uncomment functions are disabled; for example,
""for JSON. The default value is
See also the
nanorc(5) manual on your system (
man 5 nanorc).