Re: Mechaincal question Show filename of # marked

[Harry Putnam <reader@newsguy.com>]

Colin Walters <walters@cis.ohio-state.edu> writes:

> Harry Putnam <reader@newsguy.com> writes:
> 
> > Yes... It gives a nice list like this:
> > 
> > ("/home/reader/Mail/prinb/13456" "/home/reader/Mail/prinb/13455" \
> > "/home/reader/Mail/prinb/13454" "/home/reader/Mail/prinb/13453")
> > 
> > Cool.
> > 
> > How can I feed that list to a shell script?  Can I pipe it to a
> > shell script some how?
> 
> There are a few list processing functions you can use.  In Emacs 20,
> the traditional way to do this is with `mapcar', and an anonymous
> function (lambda).
> 

OK trying to get in to this, but I have no clue how that list might be
stored into a variable... In the shell, no problem but in lisp.. I'm
lost.

Imagine for a minute that you are talking to one of the inmates in `One
Flew Over the Cuckoos Nest':

Taking the first example, since I don't know how to generate a
variable containing a list I try using a single file name instead, and
insert something simple for a shell command `cat' (UUofC not
withstanding) 

I'm guessing this is like a simple `for loop' and cat will be run on
each member in turn.   So with just 1 member then maybe just on it.

(mapcar (lambda (x) (shell-command-to-string (concat "cat " x)))
        /home/reader/Mail/tmp/awk-work/13)

So C-x C-e
Symbol's value as variable is void: \
/home/reader/Mail/tmp/awk-work/13

OK, I'm guessing it wants more paren or double quotes or something

(mapcar (lambda (x) (shell-command-to-string (concat "cat " x)))
        "/home/reader/Mail/tmp/awk-work/13")

C-x C-e

("cat: 47: No such file or directory
" "cat: 104: No such file or directory
" "cat: 111: No such file or directory

[...] snip about 20 more lines

Well, I'm getting closer... May sound terribly lame, but I don't even
have a clue on how to begin looking this up in the Into or Lisp
manual.

Good thing this isn't explosive... I'd have had a serious accident by
now.