Go to the previous, next section. You can use this manual at
your leisure to read all about GDB. However, a handful of
commands are enough to get started using the debugger. This
chapter illustrates those commands. In this sample session, we
emphasize user input like this: input, to make it easier to pick
out from the surrounding output. One of the preliminary versions
of GNU m4 (a generic macro processor) exhibits the following
bug: sometimes, when we change its quote strings from the
default, the commands used to capture one macro definition
within another stop working. In the following short session, we
define a macro foo which expands to then use the defn to define
bar as the same thing. However, when we change the open quote
string to <QUOTE> and the close quote string to <UNQUOTE>, the
same procedure fails to define a new synonym $ cd gnu/m4 $ ./m4
define(foo,0000) foo 0000 define(bar,defn(`foo')) bar 0000
changequote(<QUOTE>,<UNQUOTE>)
define(baz,defn(<QUOTE>foo<UNQUOTE>)) baz C-d m4: End of input:
0: