retrieve translated messages from TEXTDOMAIN
enable expansion of some escape sequences
(ignored for compatibility)
display a help message and exit
suppress trailing newline
display version information and exit
retrieve translated message corresponding to MSGID from TEXTDOMAIN
If the TEXTDOMAIN parameter is not given, the domain is determined from the environment variable TEXTDOMAIN. If the message catalog is not found in the regular directory, another location can be specified with the environment variable TEXTDOMAINDIR.
When used with the -s option the program behaves like the echo command. But it does not simply copy its arguments to stdout. Instead those messages found in the selected catalog are translated.
The full documentation for gettext is maintained as a Texinfo manual. If the info and gettext programs are properly installed at your site, the command info gettext should give you access to the complete manual.