shell-command-to-string不能用于bash builtin，怎样执行builtin命令？

Emacs-Lisp
1

shell-command-to-string可以执行shell命令返回字符串，比如(shell-command-to-string "ls")可以正常执行返回。

但是对于bash builtin，例如alias, complete，(shell-command-to-string "alias")返回为空字符串。

我试着用make-process来实现，水平太渣，半天没写出来。

请问各路高手，怎样用elisp执行builtin命令并返回字符串?

2

试试 bash -i -c alias

(shell-command-to-string "bash -i -c alias")
;; =>
"bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
alias l='ls -l'
alias la='ls -al'
"

(shell-command-to-string "bash -i -c alias 2>/dev/null")
;; =>
"alias l='ls -l'
alias la='ls -al'
"
3

alias 为空也可能是它真的没有内容：

(shell-command-to-string "alias")
;; => ""

(shell-command-to-string "source ~/.aliases; alias")
;; => "alias l1='ls -1'
;; alias la='ls -a'
;; alias ll='ls -lh'
;; ...
;; "

但即使 alias 有内容也不一定起作用：

(shell-command-to-string "source ~/.aliases; ll /")
;; => "/bin/bash: ll: command not found
;; "

(shell-command-to-string "bash --login -i -c 'source ~/.aliases; ll /'")
;; => "total 52
;; drwxrwxr-x+ 192 root  admin   6.4K Oct 24 03:38 Applications/
;; drwxr-xr-x+  67 root  wheel   2.2K Jan  9  2017 Library/
;; drwxr-xr-x@   2 root  wheel    68B Apr 17  2016 Network/
;; drwxr-xr-x@   4 root  wheel   136B Jul 13 14:01 System/
;; drwxr-xr-x    8 root  admin   272B Sep 18 19:30 Users/
;; ...
;; "
4

综合两位的答案，用了bash的-l, -i, -c选项，去除stderr输出(不造这是个啥？)

(shell-command-to-string "bash -lic alias 2>/dev/null")