Indenting text in a file with vi/vim

If you want to indent all the text by one tab stop using vi or vim load the text file into vi and type

:1,$s/^/{tab}/

where {tab} is CTRL-V CTRL-I. This command says from line 1 to last line ($) subsitute (s) the beginning of line (^) with a TAB character.

You can also do things like move to the first line of a block and indent 5 lines using:

:.,.+4s/^/{tab}/

The . means current line and .+4 means current line plus 4 more (1 + 4 = 5).