Write files to standard output after expanding each tab into an appropriate number of spaces.
expand [options] [files]
-n (where n is a number) sets the tabs n spaces apart.
-n1 [n2, ...] (where n1, n2, . . . are numbers) specifies the tab stops.
-i converts only the initial tab into spaces.
The expand command reads from the specified files (or standard input, if no files are specified) and writes them to standard output, with each tab character expanded to an appropriate number of spaces. By default, expand assumes that the tab positions are eight spaces apart (equivalent to the -8 option).