id(1) -- Linux man page

 

NAME

id - print real and effective UIDs and GIDs  

SYNOPSIS

id [OPTION]... [USERNAME]  

DESCRIPTION

Print information for USERNAME, or the current user.

-a
ignore, for compatibility with other versions
-Z, --context
print only the security context
-g, --group
print only the effective group ID
-G, --groups
print all group IDs
-n, --name
print a name instead of a number, for -ugG
-r, --real
print the real ID instead of the effective ID, with -ugG
-u, --user
print only the effective user ID
--help
display this help and exit
--version
output version information and exit

Without any OPTION, print some useful set of identified information.  

AUTHOR

Written by Arnold Robbins and David MacKenzie.  

REPORTING BUGS

Report bugs to <bug-coreutils@gnu.org>.  

COPYRIGHT

Copyright © 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

SEE ALSO

The full documentation for id is maintained as a Texinfo manual. If the info and id programs are properly installed at your site, the command
info coreutils id

should give you access to the complete manual.