[MontelLUG] cambiare directory in un Makefile

[cesco]

> magari su "info make" c'e' anche qualche giustificazione al fatto, ma
> spero di non dover mai leggere la documentazione completa del make,
> saranno 2000 pagine :(

pero' sono ben organizzate :)
pare che esegua una shell per ogni riga perche' e' possibili far eseguire
le diverse righe in parallelo col parametro -j...
quanto al cd c'e' spiegato tutto...
be' non gli si puo' dir niente :)

ciao ciao,
cesco
----
   When it is time to execute commands to update a target, they are
executed by making a new subshell for each line.  (In practice, `make'
may take shortcuts that do not affect the results.)

   *Please note:* this implies that shell commands such as `cd' that
set variables local to each process will not affect the following
command lines. (1)  If you want to use `cd' to affect the next command,
put the two on a single line with a semicolon between them.  Then
`make' will consider them a single command and pass them, together, to
a shell which will execute them in sequence.  For example:

     foo : bar/lose
             cd bar; gobble lose > ../foo

   If you would like to split a single shell command into multiple
lines of text, you must use a backslash at the end of all but the last
subline.  Such a sequence of lines is combined into a single line, by
deleting the backslash-newline sequences, before passing it to the
shell.  Thus, the following is equivalent to the preceding example:

     foo : bar/lose
             cd bar;  \
             gobble lose > ../foo
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