--disabled-login
, which is similar to --disabled-password
, is used to create the user account without any password and to avoid prompting for it. This is to avoid any attempt to log in as git
on your Git server. The reason for this is that you're not supposed to log in to it directly, you're supposed to interact with it via git
commands only.
--gecos
sets additional information about the user you're creating (and doesn't have anything in particular to do with git
). It's not in much use these days. If you set gecos values for an account, other users can read that information using the finger
command so they can get more information about him/her/it. You can also set it separately with the chfn
command. The --gecos
switch is intended to be followed by five comma-separated values which serves as additional comments about the user. The values are:
- Full name
- Room number
- Work phone
- Home phone
- Other
You can leave out any value and skip the ends, for example --gecos 'Donald Trump,3'
would work, as would 'Donald Trump,3,,,President'
.
The main reasons why you're asked to use the --gecos
option is, I guess, to avoid prompts for these values, they are just annoying and don't make much sense these days, and may actually be a security risk. Never put your personal data here!
History
According to Wikipedia, some early Unix systems at Bell Labs used GECOS (General Comprehensive Operating System) machines, so this field was added to carry information on a user's GECOS identity.