Re: Mechaincal question Show filename of # marked

[Kai.Grossjohann@CS.Uni-Dortmund.DE (Kai Großjohann)]

On 21 Dec 2000, Harry Putnam wrote:

> How can I feed that list to a shell script?  Can I pipe it to a shell
> script some how?

Let X be a list of strings ("one" "two" "three").
Suppose you want to run the following shell command:

    ./foo one two three

This can be done as follows: (mapconcat 'identity X " ") will produce a
string "one two three" from the list.  Then you just need to tack on
"./foo " to the beginning and feed the rest to `shell-command':

    (shell-command (concat "./foo "
                           (mapconcat 'identity X " ")))

You can also use `call-process' but there you will have to deal with a
little Lisp knowledge.  `call-process' directly calls the program in
question, without going through a shell.

Now the other question: piping the list of filenames to the command on
stdin.  That's also possible.  In principle, you start the program using
`start-process'.  The return value is a process object, and then you can
send input to this process using the `process-send-string' function.
This function needs the process object plus the string to send.  After
the last string, you can use `process-send-eof' to send end-of-file to
the process.

For going over the list and sending each string to the process, you can
use mapcar as suggested by Colin.

kai
-- 
~/.signature