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Re: Better way to make sure external command exists in the system?
From: |
Jean Louis |
Subject: |
Re: Better way to make sure external command exists in the system? |
Date: |
Sun, 21 Mar 2021 17:07:18 +0300 |
User-agent: |
Mutt/2.0.6 (2021-03-06) |
* Daniel Martín <mardani29@yahoo.es> [2021-03-19 16:59]:
> > - before variables get defined, I would use `executable-find' but I
> > would like for the program loading to fail if those external
> > programs cannot be found.
>
> Why do you think that checking for the existence of programs on load is
> better? I think it would slow down loading the module, and the benefits
> are not clear to me. For example, the Elisp module may still be useful
> even if it cannot call external programs.
>
> Why is it better than simply calling `executable-find' when invoking a
> command that depends on an external program?
I would not like later invoking functions that don't work. But I do
the checks in the functions. Sometimes majority of functions belong in
the same domain that uses external commands.
(defun rcd-which-list (command-list)
"Verifies that list of shell commands COMMAND-LIST exist in
user's $PATH"
(let ((all-exist t))
(dolist (command command-list all-exist)
(unless (executable-find command)
(setq all-exist nil)
(rcd-warning-message "Shell command `%s' does not exist" command)))))
(defun optimize-image-jpg (file)
"Optimizes the JPG image with quality 70%"
(if (rcd-which-list '("mogrify"))
(let ((extension (file-name-extension file)))
(when (equal (downcase extension) "jpg")
(let* ((file (shell-double-quote file))
(command (format "mogrify -sampling-factor 4:2:0 -strip
-interlace JPEG -colorspace RGB -quality 70 \"%s\"" file)))
(message command)
(shell-command command))))
(rcd-warning-message "RCD ERROR: `mogrify' not found in $PATH")))
(defun optimize-jpg-images-dired ()
"Optimizes JPG images inside of Dired"
(interactive)
(let ((files (dired-get-marked-files)))
(dolist (file files)
(optimize-image-jpg file))
(revert-buffer)))
(defun image-resize (file &optional size)
"Resizes the JPG image with default size"
(if (rcd-which-list '("mogrify"))
(let ((extension (file-name-extension file)))
(when (or (equal (downcase extension) "jpg")
(equal (downcase extension) "png"))
(let* ((file (shell-double-quote file))
(command (format "mogrify -resize %s \"%s\"" size file)))
(message command)
(call-process-shell-command command))))
(rcd-warning-message "RCD ERROR: `mogrify' not found in `$PATH'")))
(defun image-resize-dired ()
"Resizes images"
(interactive)
(let ((files (dired-get-marked-files))
(size (read-number "Size: " *image-default-resize-size*
'(*image-resize-sizes*))))
(dolist (file files)
(image-resize file size))
(revert-buffer)))
(defun rcd-play-sound-bg (file)
"Plays found file in background"
(let ((play (executable-find "play")))
(if play
(let ((command (format "play \"%s\"" file)))
(async-shell-command command))
(message "RCD ERROR: `play' not found in $PATH"))))
(defun rcd-warning-message (format-string &rest message)
"Plays a warning sound while using function `message' as
usual."
(rcd-play-sound-bg rcd-warning-message-sound-file)
(apply 'message format-string message))
- Better way to make sure external command exists in the system?, Jean Louis, 2021/03/18
- Re: Better way to make sure external command exists in the system?, Daniel Martín, 2021/03/19
- Re: Better way to make sure external command exists in the system?,
Jean Louis <=
- Re: Better way to make sure external command exists in the system?, Emanuel Berg, 2021/03/21
- Re: Better way to make sure external command exists in the system?, Jean Louis, 2021/03/23
- Re: Better way to make sure external command exists in the system?, Emanuel Berg, 2021/03/23
- Re: Better way to make sure external command exists in the system?, Jean Louis, 2021/03/23
- Re: Better way to make sure external command exists in the system?, Emanuel Berg, 2021/03/25
- Re: Better way to make sure external command exists in the system?, Jean Louis, 2021/03/25
- Re: Better way to make sure external command exists in the system?, Emanuel Berg, 2021/03/25
- Re: Better way to make sure external command exists in the system?, Jean Louis, 2021/03/25
- Re: Better way to make sure external command exists in the system?, Emanuel Berg, 2021/03/25