How to pass something on to xargs rm?

How to pass something on to xargs rm?

[ng0]

Hi,

I have some scripts and small applications I'm slowly moving over
to guile.
One of them features this[0] line at the end which passes results on
to xargs rm. I picked a start with just (system*) everything I
had before to learn about the behavior and outcome, and improve
from this point.
I know that "|" will not work, so what else could possibly work
(for starters, in the long run I'll generalize and extend what I
currently have) to execute this command which deletes every file
listed in the previous search?

[0]: notmuch search --output=files tag:deleted | xargs -L 1 rm

Thanks,
-- 
♥Ⓐ  ng0
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Re: How to pass something on to xargs rm?

[John Darrington]

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On Tue, Dec 27, 2016 at 11:33:21AM +0000, ng0 wrote:
     Hi,
     
     I have some scripts and small applications I'm slowly moving over
     to guile.
     One of them features this[0] line at the end which passes results on
     to xargs rm. I picked a start with just (system*) everything I
     had before to learn about the behavior and outcome, and improve
     from this point.
     I know that "|" will not work, so what else could possibly work
     (for starters, in the long run I'll generalize and extend what I
     currently have) to execute this command which deletes every file
     listed in the previous search?
     
     [0]: notmuch search --output=files tag:deleted | xargs -L 1 rm
     

I think you want something like:   .... | xargs -I {} rm {}


J'

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Re: How to pass something on to xargs rm?

[ng0]

John Darrington <john@darrington.wattle.id.au> writes:

> On Tue, Dec 27, 2016 at 11:33:21AM +0000, ng0 wrote:
>      Hi,
>      
>      I have some scripts and small applications I'm slowly moving over
>      to guile.
>      One of them features this[0] line at the end which passes results on
>      to xargs rm. I picked a start with just (system*) everything I
>      had before to learn about the behavior and outcome, and improve
>      from this point.
>      I know that "|" will not work, so what else could possibly work
>      (for starters, in the long run I'll generalize and extend what I
>      currently have) to execute this command which deletes every file
>      listed in the previous search?
>      
>      [0]: notmuch search --output=files tag:deleted | xargs -L 1 rm
>      
>
> I think you want something like:   .... | xargs -I {} rm {}
>
>
> J'

I think I was a bit too verbose with my question. I meant to say:
the part behind the "|", which originates from a 1:1 conversion of
the bash based part, is ignored for obvious reasons. But what
would be a quick way (until I've learned enough on this topic
myself) to perform the deletion?
I know that the original, "notmuch search --output=files
tag:deleted | xargs -L 1 rm" works in the bash script, but for
the .scm script, everything above (fetching mail, tagging mail)
works and this part is ignored:
(system* "notmuch" "search" "--output=files" "tag:deleted" "|" "xargs" "-L" "1" "rm")

To give you an idea, this is (part of) the mailget.scm:

ng0@wasp ~$ cat mailget
#!/home/ng0/.guix-profile/bin/guile \
-s
!#

  (let* ((home (getenv "HOME"))
         ;;(tor-on (system* "." "torsocks" "on"))
         ;;(tor-off (system* "." "torsocks" "off"))
         (nm-new (system* "notmuch" "new")))
    (chdir (string-append home "/.getmail"))
    ;; tor-on
    ;;# find . -name '*.rc' | xargs -n1 -i basename {} .rc | xargs -P 2 -n1 -i getmail -r {}.rc
    ;; FIXME: *.rc not found here:
    ;; (system* "parallel" "getmail" "-q" "-r" "{}" ":::" "*.rc")
    (system* "getmail" "-r" "getmailrc_grrlz_2.rc")
    (system* "getmail" "-r" "getmailrc_runbox.rc")
    ;;tor-off
    nm-new
    (system* "notmuch" "tag" "-inbox" "+sometag" "--" "some subject")

    …
    ;; Of course I don't have literally somesubject sometag, I
       just will not expose what I tag and sort.
    …

    (system* "notmuch" "search" "--output=files" "tag:deleted" "|" "xargs" "-L" "1" "rm")
    (display "done")
    (newline))


If there is no obvious, quick solution based on what I currently
do, I will gladly accept any small pointers to subjects I could
read into and solve it later in a better version. I consider the
current script just a small hack.
One solution I can imagine is that I write some functions which
will allow me to save the output of such a search into a list I
can work with and execute the physical deletion on each element.

> -- 
> Avoid eavesdropping.  Send strong encrypted email.
> PGP Public key ID: 1024D/2DE827B3 
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>

-- 
♥Ⓐ  ng0
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Re: How to pass something on to xargs rm?

[Eli Zaretskii]

> From: ng0 <ng0@libertad.pw>
> Date: Tue, 27 Dec 2016 12:42:13 +0000
> Cc: guile-user@gnu.org
> 
> I think I was a bit too verbose with my question. I meant to say:
> the part behind the "|", which originates from a 1:1 conversion of
> the bash based part, is ignored for obvious reasons. But what
> would be a quick way (until I've learned enough on this topic
> myself) to perform the deletion?
> I know that the original, "notmuch search --output=files
> tag:deleted | xargs -L 1 rm" works in the bash script, but for
> the .scm script, everything above (fetching mail, tagging mail)
> works and this part is ignored:
> (system* "notmuch" "search" "--output=files" "tag:deleted" "|" "xargs" "-L" "1" "rm")

'system*' doesn't run the shell.  You need either 'system' (which
does), or use 'open-pipe*', 'open-input-pipe', etc.

Re: How to pass something on to xargs rm?

[Thien-Thi Nguyen]

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() ng0 <ng0@libertad.pw>
() Tue, 27 Dec 2016 12:42:13 +0000

   (system* "notmuch" "search" "--output=files" "tag:deleted" 
   "|" "xargs" "-L" "1" "rm")

Here's what i would do (untested):

(use-modules (ice-9 popen) (ice-9 rdelim))
(let* ((port (open-input-pipe "notmuch ..."))
       ;; no loop necessary, we only want one
       (filename (read-line port)))
  (close-port port)
  (delete-file filename))

Since this response is very late, i wonder if you have already
found a solution.  If so, would you mind posting it?

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