Is there a specific approach to reading device files in CL? I try the following code in SBCL but it does not appear to work:
(defparameter modem #p"/dev/ttyUSB2")
(defun read-modem()
(with-open-file (fd modem :direction :io :if-exists :append)
(loop while (peek-char nil fd) do
(format t "~A" (read-line fd))
(finish-output fd))))
I know there's output because cat /dev/ttyUSB2 shows it.
I guess, you need to read from them as from binary files. For instance, here's what I read from /dev/urandom:
> (with-open-file (fd "/dev/urandom" :direction :io :if-exists :append
:element-type 'unsigned-byte)
(read-byte fd))
161
I think your problem is with buffering.
I don't think you can turn it off in CL open, so I am afraid you have to use sb-unix:unix-open and sb-unix:unix-read.
Related
when open an R script in emacs invariably an additional buffer opens up called Flymake Log with the following message
Warning [flymake DR.R]: Disabling backend flymake-proc-legacy-flymake because (error Can’t find a suitable init function)
Following this discussion I added the following line to my init.el file:
(remove-hook 'flymake-diagnostic-functions 'flymake-proc-legacy-flymake)
but it didn't solve the problem.
Additionally, when I start an R process using M-x R an ESS buffer opens up, which says
current-prefix-arg=nil
(inferior-ess: waiting for process to start (before hook)
(inferior-ess 3): waiting for process after hook(R): inferior-ess-language-start=options(STERM='iESS', str.dendrogram.last="'", editor='emacsclient', show.error.locations=TRUE)
This happens whenever I restart my R session. It's really annoying and distracting when I constantly have to cycle through these redundant buffers. I say they are redundant, because I haven't noticed any way in which the normal R operation would be disrupted.
I'm using emacs 26.3 with ESS 18.10.3 on ubuntu 20.04 with R 3.6.3. Also, please see below my entire init.el file
(require 'package)
(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
(not (gnutls-available-p))))
(proto (if no-ssl "http" "https")))
;; Comment/uncomment these two lines to enable/disable MELPA and MELPA Stable as desired
(add-to-list 'package-archives (cons "melpa" (concat proto "://melpa.org/packages/")) t)
;;(add-to-list 'package-archives (cons "melpa-stable" (concat proto "://stable.melpa.org/packages/")) t)
(when (< emacs-major-version 24)
;; For important compatibility libraries like cl-lib
(add-to-list 'package-archives (cons "gnu" (concat proto "://elpa.gnu.org/packages/")))))
(package-initialize)
(custom-set-variables
;; custom-set-variables was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
'(package-selected-packages (quote (dracula-theme ess-smart-underscore ess)))
'(pop-up-windows nil))
(custom-set-faces
;; custom-set-faces was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.
)
;; Makes *scratch* empty.
(setq initial-scratch-message "")
;; Removes *scratch* from buffer after the mode has been set.
(defun remove-scratch-buffer ()
(if (get-buffer "*scratch*")
(kill-buffer "*scratch*")))
(add-hook 'after-change-major-mode-hook 'remove-scratch-buffer)
;; Removes *messages* from the buffer.
(setq-default message-log-max nil)
(kill-buffer "*Messages*")
;; Removes *Completions* from buffer after you've opened a file.
(add-hook 'minibuffer-exit-hook
'(lambda ()
(let ((buffer "*Completions*"))
(and (get-buffer buffer)
(kill-buffer buffer)))))
;; Don't show *Buffer list* when opening multiple files at the same time.
(setq inhibit-startup-buffer-menu t)
;; Show only one active window when opening multiple files at the same time.
(add-hook 'window-setup-hook 'delete-other-windows)
;; backup in one place. flat, no tree structure
(setq backup-directory-alist '(("" . "~/.emacs.d/backup")))
;; easier switching between windows
(windmove-default-keybindings 'control)
;; color theme
(load-theme 'dracula t)
;; matching parenthesis
(show-paren-mode 1)
;; keybindings for resizing windows
(global-set-key (kbd "S-C-<left>") 'shrink-window-horizontally)
(global-set-key (kbd "S-C-<right>") 'enlarge-window-horizontally)
(global-set-key (kbd "S-C-<down>") 'shrink-window)
(global-set-key (kbd "S-C-<up>") 'enlarge-window)
;; easier switching between buffers
(ido-mode 1)
;; no menu bar
(menu-bar-mode -1)
;; no line wrapping by default
(set-default 'truncate-lines t)
;; Disable Flymake warnings
(remove-hook 'flymake-diagnostic-functions 'flymake-proc-legacy-flymake)
;; disables ESS buffer
(setq ess-write-to-dribble t)
The last line was an attempt at permanently disabling the ESS log buffer.
Thanks to Common Lisp's powerful macro system, I can write lots of code template to generate functions avoid writing redundant code manually. What's more, it can generate different code based on configure file, so I can implement many kinds of feature just apply different configure file.
However, I have no idea how to deliver the project (It's a library):
In my opinion, maybe every config file corresponds to a package?
For example, there is a common lisp file common.lisp, it generate different functions based different configure file in compile-time.
It reads a.conf in compile-time and generate functions for PackageA and reads config b.conf in compile-time for PackageB. But in-place statement must specify only one package, the common.lisp can't both in Package A and B.
By the way, I still can't find out a proper method to get the configure path of project (So I can read and use it in compile-time to generate functions) I have tried *load-truename* for it points to the cache path which contains .fasl file on SBCLv2.0.1. But it looks like the staic files are not contained in it, so it doesn't works.
For macro-expansion the thing you care about is compile time, not load time, and the variables you want are therefore *compile-file-pathname* &/or *compile-file-truename*. ASDF likes to stash compiled files (and hence the files being loaded) somewhere known to it, which you can turn off (I do) but defaultly they end up somewhere far from their sources.
Here's an example macro which should (I have not really tested it) let you enable debugging output on a per-file basis. In real life it would be better to cache the read of the config file/s but this is mildly fiddly to get right.
(declaim (inline mutter))
(defun mutter (format &rest arguments)
(declare (ignore format arguments))
(values))
(defmacro maybe-debugging (&body forms)
(let ((config-file (and *compile-file-truename*
(make-pathname :name "debug"
:type "cf"
:defaults *compile-file-truename*))))
(multiple-value-bind (debugging cond)
(if (and config-file (probe-file config-file))
(ignore-errors
(with-standard-io-syntax
(let ((*read-eval* nil))
(with-open-file (in config-file)
(values (assoc (pathname-name *compile-file-truename*)
(read in)
:test #'string-equal)
nil)))))
(values nil nil))
(when cond
(warn "bogons reading ~A for ~A: ~A"
config-file *compile-file-truename* cond))
(if debugging
`(flet ((mutter (format &rest arguments)
(apply #'format *debug-io* format arguments)))
,#forms)
`(progn
,#forms)))))
For the single-source-file-resulting-in-multiple-object-files you could do something like this (note this repeats a variant of the above code):
(eval-when (:load-toplevel :compile-toplevel :execute)
(defvar *package-compilation-configuration*
nil
"Compile-time configuration for a package")
(defun package-config-value (key &optional (default nil))
(getf *package-compilation-configuration* key default)))
(declaim (inline mutter))
(defun mutter (format &rest args)
(declare (ignore format args))
(values))
(defmacro with-muttering (&body forms)
(if (package-config-value ':mutter)
`(flet ((mutter (fmt &rest args)
(apply #'format *debug-io* fmt args)))
,#forms)
`(progn
,#forms)))
(defun compile-file-for-package (file package &rest kws
&key (output-file nil output-file-p)
&allow-other-keys)
(with-muttering
(let* ((sf-pathname (pathname file))
(package-file (make-pathname :name (string package)
:type "cf"
:defaults sf-pathname))
(the-output-file
(if output-file-p
output-file
(compile-file-pathname
(make-pathname :name (format nil "~A-~A"
(pathname-name sf-pathname)
package)
:defaults sf-pathname))))
(*package-compilation-configuration*
(if (probe-file package-file)
(with-standard-io-syntax
(mutter "~&Compile ~A -> ~A using ~A~%"
sf-pathname the-output-file package-file)
(let ((*read-eval* nil))
(with-open-file (in package-file)
(read in))))
(progn
(mutter "~&Compile ~A -> ~A (no package)~%"
sf-pathname the-output-file)
nil))))
(apply #'compile-file file
:output-file the-output-file
kws))))
Then (compile-file-for-package "x.lisp" "y") will compile x.lisp having read configuration for package "y".
To use something like this in anger you would need to integrate it with ASDF and I don't know how to do that.
An alternative idea is just to use symlinks for the source files, and have the filename-dependent configuration depend on the symlink name, not the target name.
For my case:
project-a.asd:
(asdf:defsystem #:project-a
:components ((:static-file "my-config-file.conf")
(:static-file "common.lisp") ; shared common lisp file
(:file "project-a-package")
(:file "project-a-setup")
;; other components
)
)
project-a-setup.lisp:
(in-package #:project-a)
(eval-when (:compile-toplevel)
(defvar *mypackage* (find-package 'project-a))
(defvar *source-home* (path:dirname *compile-file-truename*))
;; read configure file
(defparameter *myconf*
(with-open-file (stream (merge-pathnames *source-home* #P"my-config-file.conf"))
(read stream)))
)
(load (merge-pathnames *source-home* #P"common.lisp"))
common.lisp:
(let ((*package* *mypackage*))
;; intern symbol
)
I am trying to add to a program I am writing, a feature whereby everything printed to the console, also gets added to a log file. This much can be done with broadcast streams. The problem is that the program may also need to abruptly exit from within a leaf function, and when I do this, the log file does not get created. This is what I have so far:
(catch 'quit
(with-open-file (log-stream "log.txt"
:direction :output
:if-exists :supersede
:if-does-not-exist :create)
(let ((*standard-output*
(make-broadcast-stream *standard-output* log-stream)))
(format t "abc~%")
(throw 'quit nil))))
When I run the above code (SBCL 1.4.2, Windows 7), the file log.txt does not get created. The same is true if I replace (throw 'quit nil) with (quit). However, if I remove that line altogether and just let the program exit by falling off the end of the file, the log file does get correctly created, which suggests it's a caching issue.
Is that the correct diagnosis? If so, is there a way to tell the compiler not to cache that file, or to exit with rather than without writing cached data?
This is the behaviour described in the standard for WITH-OPEN-FILE:
If a new output file is being
written, and control leaves abnormally, the file is aborted and the file system is left,
so far as possible, as if the file had never been opened.
The following explicitly closes the file:
(catch 'quit
(with-open-file (log-stream "/tmp/log.txt"
:direction :output
:if-exists :supersede
:if-does-not-exist :create)
(let ((*standard-output* (make-broadcast-stream *standard-output* log-stream)))
(unwind-protect (progn
(format t "abc~%")
(throw 'quit nil))
(finish-output)
(close log-stream :abort nil)))))
The :abort nil value is the default one, it is made explicit here for the sake of the answer.
I was hoping to experiment with cl-async to run a series of external programs with a large combinations of command line arguments. However, I can't figure out how to read the stdout of the processes launched with as:spawn.
I would typically use uiop which makes it easy to capture the process output:
(let ((p (uiop:launch-program ... :output :stream)))
(do-something-else-until-p-is-done)
(format t "~a~%" (read-line (uiop:process-info-output p))))
I've tried both :output :pipe and :output :stream options to as:spawn and executing (as:process-output process-object) in my exit-callback shows the appropriate pipe or async-stream objects but I can't figure out how to read from them.
Can anyone with experience with this library tell how to accomplish this?
So you go to your repl and type:
CL-USER> (documentation 'as:spawn 'function)
And you read whatever comes out (or put your point on the symbol and hit C-c C-d f). If you read it you’ll see that the format for the :input, etc arguments is either :pipe, (:pipe args...), :stream, or (:stream args...) (or some other options). And that :stream behaves similarly to :pipe but gives output of a different type and that for details of args one should look at PIPE-CONNECT so you go and look up the documentation for that. Well it tells you what the options are but it isn’t very useful. What’s the documentation/description of PIPE or STREAM? Well it turns out that pipe is a class and a subclass of STREAMISH. What about PROCESS that’s a class too and it has slots (and accessors) for things like PROCESS-OUTPUT. So what is a good plan for how to figure out what to do next? Here’s a suggestion:
Spawn a long running process (like cat foo.txt -) with :output :stream :input :pipe say
Inspect the result (C-c C-v TAB)
Hopefully it’s an instance of PROCESS. What is it’s output? Inspect that
Hopefully the output is a Gray stream (ASYNC-STREAM). Get it into your repl and see what happens if you try to read from it?
And what about the input? See what type that has and what you can do with it
The above is all speculation. I’ve not tried running any of this but you should. Alternatively go look at the source code for the library. It’s already on your computer and if you can’t find it it’s on GitHub. There are only about half a dozen source files and they’re all small. Just read them and see what you can learn. Or go to the symbol you want to know about and hit M-. to jump straight to its definition. Then read the code. Then see if you can figure out what to do.
I found the answer in the test suite. The output stream can only be processed asynchronously via a read call-back. The following is simple example for posterity
(as:start-event-loop
(lambda ()
(let ((bytes (make-array 0 :element-type '(unsigned-byte 8))))
(as:spawn "./test.sh" '()
:exit-cb (lambda (proc exit-status term-signal)
(declare (ignore proc exit-status term-signal))
(format t "proc output:~%~a"
(babel:octets-to-string bytes)))
:output (list :stream
:read-cb (lambda (pipe stream)
(declare (ignore pipe))
(let ((buf (make-array 128 :element-type '(unsigned-byte 8))))
(loop for n = (read-sequence buf stream)
while (plusp n) do
(setf bytes
(concatenate '(vector (unsigned-byte 8))
bytes
(subseq buf 0 n)))))))))))
with
$ cat test.sh
#!/bin/bash
sleep_time=$((1+$RANDOM%10))
echo "Process $$ will sleep for $sleep_time"
sleep $sleep_time
echo "Process $$ exiting"
yields the expected output
It seems there is NO ANSI standard way to execute an external program and get its output as the following SBCL special code does:
(defmacro with-input-from-program ((stream program program-args environment)
&body body)
"Creates an new process of the specified by PROGRAM using
PROGRAM-ARGS as a list of the arguments to the program. Binds the
stream variable to an input stream from which the output of the
process can be read and executes body as an implicit progn."
#+sbcl
(let ((process (gensym)))
`(let ((,process (sb-ext::run-program ,program
,program-args
:output :stream
:environment ,environment
:wait nil)))
(when ,process
(unwind-protect
(let ((,stream (sb-ext:process-output ,process)))
,#body)
(sb-ext:process-wait ,process)
(sb-ext:process-close ,process))))))
The following CCL code reports "ERROR: value # is not of the expected type (AND CCL::BINARY-STREAM INPUT-STREAM)"
#+clozure
(let ((process (gensym)))
`(let ((,process (ccl:run-program "/bin/sh" (list "-c" (namestring ,program))
:input nil :output :stream :error :stream
:wait nil)))
(when ,process
(unwind-protect
(let ((,stream (ccl::external-process-output-stream ,process)))
,#body)
;(ccl:process-wait (ccl:process-whostate ,process) nil)
(close (ccl::external-process-output-stream ,process))
(close (ccl::external-process-error-stream ,process))))))
I know little CCL. I want to know how i can modify this code to support CCL ?
Any suggestion is appreciated !
Apparently trivial-shell:shell-command doesn't allow exactly what you want (it executes the external command synchronously and returns the whole output).
You could look into CCL's run-program. See:
run-program;
Does there exist standard way to run external program in Common Lisp? (this is a question that is similar to your question);
external-program (suggested in one of the answers in the question above) is supported by Quicklisp and it seems to have better support for executing external programs.
You should use trivial-shell.
Trivial shell is a simple platform independent interface to the underlying Operating System.