How to indent a block of text in an m4 macro

问题

Is there a good way to uniformly indent a block of text in an m4 macro? In other words, the macro

define(`mytext',dnl
This is
a
piece of text
that I would like
to indent)
mytext

generates

This is
a
piece of text
that I would like
to indent

I'd like to have a way to indent the whole block of text to a specified amount.

回答1:

How about patsubst:

patsubst(mytext,`^', ` ')

来源：https://stackoverflow.com/questions/29026753/how-to-indent-a-block-of-text-in-an-m4-macro