How to view man page using Info in Emacs? - emacs

Question

I can view man pages using info in the terminal:
info pthread_create
However, it is not possible with info in Emacs, even with info-apropos or info-menu.

Answer 1

EDIT:
It seems that fall-backs are not in the concept of Info-mode.
There follows a work-around applying advice. It does not work perfect but around the missing feature ;-).
It defines a fall-back for Info-goto-node (in Info-mode bound to g) and for Info-menu (in Info-mode bound to m).
Furthermore, it adds manual-apropos to info-apropos.
(require 'woman)
(defun Info-man-completion (_caller _info string predicate action)
"Add man entries to info completion."
;; prepare woman:
(unless (and woman-expanded-directory-path woman-topic-all-completions)
(setq woman-expanded-directory-path
(woman-expand-directory-path woman-manpath woman-path)
woman-topic-all-completions
(woman-topic-all-completions woman-expanded-directory-path)))
;; do completions:
(cond
((null action) ;; try-completion
;; shortest wins
(let ((_man (try-completion string woman-topic-all-completions)))
(cond
((eq _info t)
t)
((eq _man t)
t)
((and (stringp _info) (stringp _man))
(if (> (length _info) (length _man))
_man
_info))
((stringp _info)
_info)
(t _man)
)))
((eq action t) ;; all-completions
(let ((_man (all-completions string woman-topic-all-completions)))
(append _info _man)
))
((eq action 'lambda) ;; test-completion
(try-completion string _caller))
((eq action 'metadata) ;; state of current completion
'(metadata) ;; no specification
)))
;; args: string predicate code
(defadvice Info-read-node-name-1 (around man activate)
"Add man entries to info completion."
(setq ad-return-value (apply 'Info-man-completion 'Info-read-node-name-1 ad-do-it (ad-get-args 0))))
;;
(defadvice Info-complete-menu-item (around man activate)
"Add man entries to info completion."
(setq ad-return-value (apply 'Info-man-completion 'Info-complete-menu-item ad-do-it (ad-get-args 0))))
(defadvice Info-goto-node (around man activate)
"If no info node is found for string lookup and show man entry."
(condition-case err
ad-do-it
(user-error
(let ((err-str (car-safe (cdr err))))
(if (and (stringp err-str)
(string-match "No such node or anchor:" err-str))
(man (ad-get-arg 0))
(signal 'user-error err-str)
)))))
(defadvice Info-menu (around man activate)
"If no info menu entry is found for string lookup and show man entry."
(condition-case err
ad-do-it
(user-error
(let ((err-str (car-safe (cdr err))))
(if (and (stringp err-str)
(string-match "No such item in menu" err-str))
(man (ad-get-arg 0))
(signal 'user-error err-str)
)))))
(defadvice Info-apropos-find-node (after man activate)
"Add man appropos to info appropos."
(let (item)
(goto-char (point-max))
(let ((inhibit-read-only t))
(insert "\nMatches found by man-apropos\n\n")
(let ((beg (point))
(nodeinfo (assoc nodename Info-apropos-nodes)))
(if nodeinfo
(let ((search-string (nth 1 nodeinfo)))
(call-process "apropos" nil t t search-string)
(goto-char beg)
(while (re-search-forward "^\\(\\(?:[[:alnum:]]\\|\\s_\\)+\\)\\(?:[[:blank:]]+\\[\\]\\)?\\([[:blank:]]+([[:alnum:]]+)\\)[[:blank:]]+-[[:blank:]]+\\(.*\\)$" nil t)
(replace-match (replace-regexp-in-string "\\\\" "\\\\\\\\" (format "* %-38s.%s"
(format "%s:" (match-string 1))
(concat (match-string 1) (match-string 2))
(match-string 3))))))
(man nodename)
)))))
Info gives an error that the node is not available. Thereafter, the manual page is shown if there is one.

Answer 2

[Edited]
EmacsWiki says that iman:
Opens either an info format manual with InfoMode or a man page with
ManMode.
It links to the author's website:
http://homepage1.nifty.com/bmonkey/emacs/elisp/iman.el

Answer 3

Found M-x woman MANPAGE RET to most convenient way to call manpages from inside Emacs.