doomemacs/core/autoload/process.el
Henrik Lissner b426e21ef1
Refactor doom-num-cpus
Adds error handling.
2020-11-30 23:35:03 -05:00

70 lines
2.8 KiB
EmacsLisp

;;; core/autoload/process.el -*- lexical-binding: t; -*-
;;;###autoload
(defun doom-call-process (command &rest args)
"Execute COMMAND with ARGS synchronously.
Returns (STATUS . OUTPUT) when it is done, where STATUS is the returned error
code of the process and OUTPUT is its stdout output."
(with-temp-buffer
(cons (or (apply #'call-process command nil t nil (remq nil args))
-1)
(string-trim (buffer-string)))))
;;;###autoload
(defun doom-exec-process (command &rest args)
"Execute COMMAND with ARGS synchronously.
Unlike `doom-call-process', this pipes output to `standard-output' on the fly to
simulate 'exec' in the shell, so batch scripts could run external programs
synchronously without sacrificing their output.
Warning: freezes indefinitely on any stdin prompt."
;; FIXME Is there any way to handle prompts?
(with-temp-buffer
(cons (let ((process
(make-process :name "doom-sh"
:buffer (current-buffer)
:command (cons command (remq nil args))
:connection-type 'pipe))
done-p)
(set-process-filter
process (lambda (_process output)
(princ output (current-buffer))
(princ output)))
(set-process-sentinel
process (lambda (process _event)
(when (memq (process-status process) '(exit stop))
(setq done-p t))))
(while (not done-p)
(sit-for 0.1))
(process-exit-status process))
(string-trim (buffer-string)))))
(defvar doom--num-cpus nil)
;;;###autoload
(defun doom-num-cpus ()
"Return the max number of processing units on this system.
Tries to be portable. Returns 1 if cannot be determined."
(or doom--num-cpus
(setq doom--num-cpus
(let ((cpus
(cond ((getenv "NUMBER_OF_PROCESSORS"))
((executable-find "nproc")
(doom-call-process "nproc"))
((executable-find "sysctl")
(doom-call-process "sysctl" "-n" "hw.ncpu")))))
(max
1 (or (cl-typecase cpus
(string
(condition-case _
(string-to-number cpus)
(wrong-type-argument
(user-error "NUMBER_OF_PROCESSORS contains an invalid value: %S"
cpus))))
(consp
(if (zerop (car cpus))
(string-to-number (cdr cpus))
(user-error "Failed to look up number of processors, because:\n\n%s"
(cdr cpus)))))
1))))))