;;; cpio-newc.el --- handle portable newc cpio archives. -*- coding: utf-8 -*-
;; COPYRIGHT
;;
;; Copyright © 2019-2020 Free Software Foundation, Inc.
;; All rights reserved.
;;
;; This program is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;;
;; Author: Douglas Lewan <d.lewan2000@gmail.com>
;; Maintainer: Douglas Lewan <d.lewan2000@gmail.com>
;; Created: 2015 Jan 03
;; Version: 0.17
;; Keywords: files
;;; Commentary:
;;; Documentation:
;; Naming conventions:
;;
;; All global variables pertaining to newc-formatted cpio-archives
;; begin '*cpio-newc-...'.
;; Every FIELD in a header have corrsponding regular expressions
;; to match them named '*cpio-newc-FIELD-re*'.
;; The variable *cpio-newc-header-re* uses those regular expressions
;; to parse a newc header.
;; Every FIELD's matching substring has an index named
;; *cpio-newc-FIELD-idx*'.
;;
;; HEREHERE The following are currently UNUSED:
;; Every FIELD has a function (cpio-newc-get-FIELD)
;; that operates on a parsed header to retrieve the value of that FIELD.
;; (It's not obvious that such functions need to be here.
;; After all, a parsed header has the same structure for each format.
;;; Code:
;;
;; Dependencies
;;
(eval-when-compile (require 'cpio-generic)) ;For `with-writable-buffer'!
(require 'cl-lib)
;; (condition-case err
;; (require 'cpio-generic)
;; (error
;; (if (file-exists-p (concat default-directory "cpio-generic.elc"))
;; (load-file (concat default-directory "cpio-generic.elc"))
;; (load-file (concat default-directory "cpio-generic.el")))))
;;;;;;;;;;;;;;;;
;; Things to make the byte compiler happy.
(defvar *cpio-catalog*)
(defvar *cpio-padding-modulus*)
(declare-function cpio-entry-name "cpio-mode.el")
(declare-function cpio-ino "cpio-mode.el")
(declare-function cpio-mode-value "cpio-mode.el")
(declare-function cpio-uid "cpio-mode.el")
(declare-function cpio-gid "cpio-mode.el")
(declare-function cpio-nlink "cpio-mode.el")
(declare-function cpio-mtime "cpio-mode.el")
(declare-function cpio-entry-size "cpio-mode.el")
(declare-function cpio-dev-maj "cpio-mode.el")
(declare-function cpio-dev-min "cpio-mode.el")
(declare-function cpio-entry-attrs-from-catalog-entry "cpio-mode.el")
(declare-function cpio-contents-start "cpio-mode.el")
(declare-function cpio-entry-attrs "cpio-mode.el")
;; EO things for the byte compiler.
;;;;;;;;;;;;;;;;
;;
;; Vars
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; newc header format vars
;;
(defconst *cpio-newc-header-length* (length "07070100000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000B00000000")
"The length of a newc header.")
;; MAINTENANCE The following must remain in synch with *cpio-newc-header-re*.
(defconst *cpio-newc-magic-re* "070701"
"RE to match the magic number of a newc archive.")
(setq *cpio-newc-magic-re* "070701")
(defconst *cpio-newc-ino-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_ino field in a newc header.")
(setq *cpio-newc-ino-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-mode-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_mode field in a newc header.")
(setq *cpio-newc-mode-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-uid-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_uid field in a newc header.")
(setq *cpio-newc-uid-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-gid-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_gid field in a newc header.")
(setq *cpio-newc-gid-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-nlink-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_nlink field in a newc header.")
(setq *cpio-newc-nlink-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-mtime-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_mtime field in a newc header.")
(setq *cpio-newc-mtime-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-filesize-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_filesize field in a newc header.")
(setq *cpio-newc-filesize-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-dev-maj-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_dev field in a newc header.")
(setq *cpio-newc-dev-maj-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-dev-min-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_dev field in a newc header.")
(setq *cpio-newc-dev-min-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-rdev-maj-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_rdev field in a newc header.")
(setq *cpio-newc-rdev-maj-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-rdev-min-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_rdev field in a newc header.")
(setq *cpio-newc-rdev-min-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-rdev-min-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_rdev field in a newc header.")
(setq *cpio-newc-rdev-min-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-namesize-re* "[[:xdigit:]]\\{8\\}"
"RE to match the c_namesize field in a newc header.")
(setq *cpio-newc-namesize-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-chksum-re* "[[:xdigit:]]\\{8\\}"
"RE to match the CRC checksum in a newc header.")
(setq *cpio-newc-chksum-re* "[[:xdigit:]]\\{8\\}")
(defconst *cpio-newc-filename-re* "[[:print:]]+"
"RE to match the c_filename field in a newc header.")
(setq *cpio-newc-filename-re* "[[:print:]]+")
(defconst *cpio-newc-header-re* ()
"RE to match newc header format cpio archives.")
(setq *cpio-newc-header-re* (concat "\\(" *cpio-newc-magic-re* "\\)"
"\\(" *cpio-newc-ino-re* "\\)"
"\\(" *cpio-newc-mode-re* "\\)"
"\\(" *cpio-newc-uid-re* "\\)"
"\\(" *cpio-newc-gid-re* "\\)"
"\\(" *cpio-newc-nlink-re* "\\)"
"\\(" *cpio-newc-mtime-re* "\\)"
"\\(" *cpio-newc-filesize-re* "\\)"
"\\(" *cpio-newc-dev-maj-re* "\\)"
"\\(" *cpio-newc-dev-min-re* "\\)"
"\\(" *cpio-newc-rdev-maj-re* "\\)"
"\\(" *cpio-newc-rdev-min-re* "\\)"
"\\(" *cpio-newc-namesize-re* "\\)"
"\\(" *cpio-newc-chksum-re* "\\)"
"\\(" *cpio-newc-filename-re* "\\)"
"\0"))
(let ((i 0))
(defconst *cpio-newc-magic-re-idx* 0 ; (setq i (1+ i))
"RE to match the magic number in a newc header.")
(setq *cpio-newc-magic-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-ino-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the inode.")
(setq *cpio-newc-ino-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-mode-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the mode.")
(setq *cpio-newc-mode-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-uid-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the UID.")
(setq *cpio-newc-uid-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-gid-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the GID.")
(setq *cpio-newc-gid-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-nlink-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the nlink.")
(setq *cpio-newc-nlink-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-mtime-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the mtime.")
(setq *cpio-newc-mtime-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-filesize-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the filesize.")
(setq *cpio-newc-filesize-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-dev-maj-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the dev.")
(setq *cpio-newc-dev-maj-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-dev-min-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the dev.")
(setq *cpio-newc-dev-min-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-rdev-maj-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the rdev.")
(setq *cpio-newc-rdev-maj-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-rdev-min-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the rdev.")
(setq *cpio-newc-rdev-min-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-namesize-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the namesize.")
(setq *cpio-newc-namesize-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-chksum-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the chksum.")
(setq *cpio-newc-chksum-re-idx* (setq i (1+ i)))
(defconst *cpio-newc-filename-re-idx* 0 ; (setq i (1+ i))
"Index of the sub RE from *cpio-newc-header-re* to parse the namesize.")
(setq *cpio-newc-filename-re-idx* (setq i (1+ i))))
;;
;; EO newc header variables.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; *cpio-newc-magic-re*
(defconst *cpio-newc-magic* *cpio-newc-magic-re*
"The string that identifies an entry as a NEWC style cpio(1) entry.")
(setq *cpio-newc-magic* *cpio-newc-magic-re*)
(defconst *cpio-newc-field-width* 8
"The width of all of the fields in a newc header.")
(setq *cpio-newc-field-width* 8)
(defconst *cpio-newc-padding-modulus* 4
"The modulus to which some things are padded in a NEWC cpio archive.")
(setq *cpio-newc-padding-modulus* 4)
(defconst *cpio-newc-padding-char* ?\0
"A character to be used for padding headers and entry contents
in a newc cpio archive.")
(setq *cpio-newc-padding-char* ?\0)
(defconst *cpio-newc-padding-str* "\0"
"A single character string of the character
to be used for padding headers and entry contents
in a newc cpio archive.")
(setq *cpio-newc-padding-str* "\0")
(let ((i 0)
(l (length *cpio-newc-magic-re*)))
(defconst *cpio-newc-magic-field-offset* i)
(setq *cpio-newc-magic-field-offset* i)
(setq i (1+ i))
(defconst *cpio-newc-ino-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-ino-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-mode-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-mode-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-uid-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-uid-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-gid-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-gid-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-nlink-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-nlink-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-mtime-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-mtime-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-filesize-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-filesize-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-dev-maj-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-dev-maj-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-dev-min-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-dev-min-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-rdev-maj-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-rdev-maj-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-rdev-min-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-rdev-min-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-namesize-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-namesize-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-chksum-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-chksum-field-offset* (+ l (* *cpio-newc-field-width* (1- i))))
(setq i (1+ i))
(defconst *cpio-newc-name-field-offset* (+ l (* *cpio-newc-field-width* i)))
(setq *cpio-newc-name-field-offset* (+ l (* *cpio-newc-field-width* (1- i)))))
(defconst *cpio-newc-trailer* "07070100000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000B00000000TRAILER!!!\0\0\0\0"
"The TRAILER string for a newc archive.")
(defcustom *cpio-newc-blocksize* 512
"The default block size for this cpio archive.
Taken from cpio-2.12/src/global.c."
:type 'integer
:group 'cpio)
;;
;; Library
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Functions for working with a cpio newc header
;;
(defun cpio-newc-header-at-point (&optional where)
"Return the header string at or following point WHERE.
If WHERE is not given, then use point.
CAVEATS:
1. This searches for the magic number at the begining of the header;
if WHERE is inside the magic number, then the search will fail.
This works best if you are (looking-at) a header.
2. This returns the pure header;
it does not provide the filename itself."
(unless where (setq where (point)))
(let ((fname "cpio-newc-header-at-point")
(found nil))
(save-match-data
(cond ((looking-at *cpio-newc-header-re*)
(match-string-no-properties 0))
(t
(forward-char (length *cpio-newc-magic-re*))
(while (and (re-search-backward *cpio-newc-magic-re* (point-min) t)
(not (setq found (looking-at *cpio-newc-header-re*)))))
(if found
(match-string-no-properties 0)))))))
;;;;;;;;;;;;;;;;
;;
;; Parsing a header
;;
(defun cpio-newc-parse-header (header-string)
"Return the internal entry header structure encoded in HEADER-STRING.
The optional argument WHERE should be a buffer location
at the beginning of a known cpio newc header.
If WHERE is not given, then take point and hope.
This function does NOT get the contents."
(let ((fname "cpio-newc-parse-header")
(namesize)
(filesize)
(result))
;; There's an arguable level of redundancy here,
;; but the caller likely grabbed HEADER-STR
;; from the buffer and we're using the string proper.
;; This call establishes the match-data
;; that the subsequent calls will use.
(save-match-data
(string-match *cpio-newc-header-re* header-string)
(setq result
(vector (cpio-newc-parse-ino header-string)
(cpio-newc-parse-mode header-string)
(cpio-newc-parse-uid header-string)
(cpio-newc-parse-gid header-string)
(cpio-newc-parse-nlink header-string)
(cpio-newc-parse-mtime header-string)
(setq filesize (cpio-newc-parse-filesize header-string))
(cpio-newc-parse-dev-maj header-string)
(cpio-newc-parse-dev-min header-string)
(cpio-newc-parse-rdev-maj header-string)
(cpio-newc-parse-rdev-min header-string)
(setq namesize (cpio-newc-parse-namesize header-string))
(cpio-newc-parse-chksum header-string)
(cpio-newc-parse-name header-string namesize))))
;; (cpio-newc-header-size header-string namesize))))
(if (cpio-entry-name result)
result
nil)))
(defun cpio-newc-header-size (header-string namesize)
"Determine the length of the header implied by the given HEADER-STRING."
(let ((fname "cpio-newc-header-size")
;; CAUTION: The following assumes that (string-to-number) doesn't care about leading zeroes.
;; The namesize in the header includes the terminating NULL at the end of the name.
(local-namesize (1- namesize))
(total -1))
(if (= 0 (mod (setq total (+ 1 *cpio-newc-name-field-offset* local-namesize))
*cpio-newc-padding-modulus*))
(setq total (1+ total)))
(cg-round-up total *cpio-newc-padding-modulus*)))
(defun cpio-newc-parse-magic (header-string)
"Get the magic field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-magic")
(this-offset *cpio-newc-magic-field-offset*)
(end-offset (+ this-offset (length *cpio-newc-magic-re*))))
(substring header-string this-offset end-offset)))
(defun cpio-newc-parse-ino (header-string)
"Get the ino field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-ino")
(this-offset *cpio-newc-ino-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-mode (header-string)
"Get the mode field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-mode")
(this-offset *cpio-newc-mode-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset)16)))
(defun cpio-newc-parse-uid (header-string)
"Get the uid field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-uid")
(this-offset *cpio-newc-uid-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-gid (header-string)
"Get the gid field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-gid")
(this-offset *cpio-newc-gid-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-nlink (header-string)
"Get the nlink field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-nlink")
(this-offset *cpio-newc-nlink-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-mtime (header-string)
"Get the mtime field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-mtime")
(this-offset *cpio-newc-mtime-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*))
(time-value ()))
(setq time-value (string-to-number (substring header-string this-offset end-offset) 16))
(setq time-value (list (lsh (logand #xFFFF0000 time-value) -16) (logand #xFFFF)))))
(defun cpio-newc-parse-filesize (header-string)
"Get the filesize from the HEADER-STRING."
(let* ((fname "cpio-newc-parse-filesize")
(this-offset *cpio-newc-filesize-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-dev-maj (header-string)
"Get the dev-maj field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-dev-maj")
(this-offset *cpio-newc-dev-maj-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-dev-min (header-string)
"Get the dev-min field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-dev-min")
(this-offset *cpio-newc-dev-min-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-rdev-maj (header-string)
"Get the rdev-maj field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-rdev-maj")
(this-offset *cpio-newc-rdev-maj-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-rdev-min (header-string)
"Get the rdev-min field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-rdev-min")
(this-offset *cpio-newc-rdev-min-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-namesize (header-string)
"Get the namesize field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-namesize")
(this-offset *cpio-newc-namesize-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-chksum (header-string)
"Get the chksum field from HEADER-STRING."
(let* ((fname "cpio-newc-parse-chksum")
(this-offset *cpio-newc-chksum-field-offset*)
(end-offset (+ this-offset *cpio-newc-field-width*)))
(string-to-number (substring header-string this-offset end-offset) 16)))
(defun cpio-newc-parse-name (header-string namesize)
"Get the name field from HEADER-STRING.
N.B. When called with the correct namesize, this includes the terminating \0."
(let* ((fname "cpio-newc-parse-name")
(this-offset *cpio-newc-name-field-offset*)
(tmp-string (substring header-string this-offset (+ this-offset namesize -1))))
(if (string-equal tmp-string "TRAILER!!!")
nil
tmp-string)))
;; Is this not M-x cpio-dired-find-entry?
(defun cpio-newc-parse-contents (header-string where namesize filesize)
"Return the contents implied by point and HEADER-STRING.
CAVEATS: See `cpio-newc-parse-magic'.
This requires the point to be at the start of HEADER-STRING in the buffer.
After all that's where the contents are, not in the header."
(let ((fname "cpio-newc-parse-contents"))
(buffer-substring-no-properties (+ where namesize)
(+ where namesize filesize))))
;;;;;;;;;;;;;;;;
;;
;; Header construction
;;
(defun cpio-newc-make-header-string (attrs &optional contents)
"Make a NEWC style padded cpio header for the given ATTRibuteS.
This function does NOT include the contents."
(let ((fname "cpio-newc-make-header-string")
(name (cpio-entry-name attrs))
(header-string))
(setq header-string (concat (cpio-newc-make-magic attrs)
(cpio-newc-make-ino attrs)
(cpio-newc-make-mode attrs)
(cpio-newc-make-uid attrs)
(cpio-newc-make-gid attrs)
(cpio-newc-make-nlink attrs)
(cpio-newc-make-mtime attrs)
(cpio-newc-make-filesize attrs)
(cpio-newc-make-dev-maj attrs)
(cpio-newc-make-dev-min attrs)
(cpio-newc-make-rdev-maj attrs)
(cpio-newc-make-rdev-min attrs)
(format "%08X" (1+ (length name)))
(cpio-newc-make-chksum attrs)
name
"\0"))
(setq header-string (cg-pad-right header-string (cg-round-up (length header-string) *cpio-newc-padding-modulus*) "\0"))
;; Check (at least during development).
(if (string-match-p *cpio-newc-header-re* header-string)
header-string
(error "%s(): I built a bad header: [[%s]]" fname header-string))))
(defun cpio-newc-make-magic (attrs)
"Return the NEWC magic header string"
(let ((fname "cpio-newc-make-magic"))
*cpio-newc-magic*))
(defun cpio-newc-make-ino (attrs)
"Return a string value for the inode from the file attributes ATTRS."
(let ((fname "cpio-newc-make-ino")
(ino (cpio-ino attrs)))
(format "%08X" ino)))
(defun cpio-newc-make-mode (attrs)
"Return a string value for the mode from the file attributes ATTRS."
(let ((fname "cpio-newc-make-mode"))
(format "%08X" (cpio-mode-value attrs))))
(defun cpio-newc-make-uid (attrs)
"Return an integer string value for the UID from the file attributes ATTRS."
(let ((fname "cpio-newc-make-uid")
(uid (cpio-uid attrs)))
(format "%08X" uid)))
(defun cpio-newc-make-gid (attrs)
"Return an integer string value for the GID from the file attributes ATTRS."
(let ((fname "cpio-newc-make-gid")
(gid (cpio-gid attrs)))
(format "%08X" gid)))
(defun cpio-newc-make-nlink (attrs)
"Return an integer string value for the number of links from the file attributes ATTRS."
(let ((fname "cpio-newc-make-nlink"))
(format "%08X" (cpio-nlink attrs))))
(defun cpio-newc-make-mtime (attrs)
"Return a string value for the mod time from the file attributes ATTRS."
(let ((fname "cpio-newc-make-mtime")
(mod-time (cpio-mtime attrs)))
;; We're only about 1/2 way through using this up it seems.
;; Still, time will eventually overflow a 32 bit unsigned integer.
(format "%08X" (float-time mod-time))))
(defun cpio-newc-make-filesize (attrs)
"Return an 8 digit hex string for the filesize attribute among the given ATTRs."
(let ((fname "cpio-newc-make-filesize"))
(format "%08X" (cpio-entry-size attrs))))
(defun cpio-newc-make-dev-maj (attrs)
"Return a string value for the major device from the file attributes ATTRS."
(let ((fname "cpio-newc-make-dev-maj")
(dev (cpio-dev-maj attrs)))
(format "%08X" dev)))
(defun cpio-newc-make-dev-min (attrs)
"Return a string value for the minor device from the file attributes ATTRS."
(let ((fname "cpio-newc-make-dev-min")
(dev (cpio-dev-min attrs)))
(format "%08X" dev)))
(defun cpio-newc-make-rdev-maj (attrs)
"Return a string value for the major rdev from the file attributes ATTRS."
(let ((fname "cpio-newc-make-rdev-maj")
(rdev))
;; MAINTENANCE Every concrete example I look at has this value for rdev-maj.
;; That's apparently the case for all file types except char and block special.
;; And, yes, I have to figure out those calculations yet.
"00000000"))
(defun cpio-newc-make-rdev-min (attrs)
"Return a string value for the minor rdev from the file attributes ATTRS."
(let ((fname "cpio-newc-make-rdev-min"))
;; MAINTENANCE Every concrete example I look at has this value for rdev-maj.
;; See (cpio-newc-make-rdev-maj) for more information.
"00000000"))
(defun cpio-newc-make-chksum (attrs)
"Return a string value for the newc cpio entry from the file attributes ATTRS."
(let ((fname "cpio-newc-make-chksum"))
;; According to the info this is only populated for crc archives.
;; It has always been 00000000 for my concrete newc examples.
;; And, indeed, it's only set in crc archives.
;; See copyout.c->writeout-defered-file() and nowhere else.
"00000000"))
;; Filename is not one of ATTRS. ∴ It doesn't get a constructor here.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Functions for whole entries
;;
(defun cpio-newc-parse-header-at-point ()
"Parse the newc cpio header that begins at point.
If there is no header there, then signal an error."
(let ((fname "cpio-newc-parse-header-at-point"))
(unless (looking-at-p *cpio-newc-header-re*)
(error "%s(): point is not looking at a newc header." fname))
(cpio-newc-parse-header (match-string-no-properties 0))))
(defun cpio-newc-goto-next-header ()
"Move the point to the beginning of the next newc cpio header.
If point is looking-at such a header, then that is the next one
and there is no movement.
\(Thus, a caller may have to make sure that point has moved.\)
This returns the a marker for point where the header is found, if one is found.
It returns NIL otherwise.
This sets match-data for the entire header and each field."
(let ((fname "cpio-newc-goto-next-header")
(header-start)
(header-string))
(cond ((re-search-forward *cpio-newc-header-re* (point-max) t)
(setq header-start (goto-char (match-beginning 0)))
(setq header-string (match-string-no-properties 0))
(cons (point-marker) header-string))
(t nil))))
(defun cpio-newc-build-catalog ()
"Build an internal structure reflecting the contents of the newc cpio archive in the current buffer.
See the variable *cpio-catalog* for more information.
CAVEAT: This respects neither narrowing nor the point."
(let ((fname "cpio-newc-build-catalog")
(header-start) ;A marker.
(header-end)
(that-header-string)
(header-info ())
(parsed-header t)
(filesize) ;A marker.
(contents-start)
(contents-end) ;NOT NEEDED?
(those-contents) ;
(catalog ()))
(widen)
(goto-char (point-min))
(while (and (setq header-info (cpio-newc-goto-next-header))
(setq header-start (car header-info))
(setq that-header-string (cdr header-info))
parsed-header)
(cond ((setq parsed-header (cpio-newc-parse-header-at-point))
(setq filesize (cpio-entry-size parsed-header))
(forward-char (length that-header-string))
(setq header-end (point))
;; A little bit of arithmétic gymnastics here
;; because cpio, being written in C, starts counting at 0, but
;; emacs' points start at 1.
(goto-char (1+ (cg-round-up (1- header-end) *cpio-padding-modulus*)))
(setq contents-start (point-marker))
(set-marker-insertion-type contents-start *cg-insert-after*)
;; It feels like I really want a function for getting the contents.
;; But it's not obvious what is simpler or appropriately more general
;; than this one-liner.
;; Indeed. (setq those-contents (buffer-substring-no-properties contents-start contents-end))
(push (cons (cpio-entry-name parsed-header)
(vector
parsed-header
header-start
contents-start
'cpio-mode-entry-unmodified))
catalog)
(setq contents-end (+ contents-start filesize -1))
(goto-char contents-end))
(t t)))
(nreverse catalog)))
;; catalog))
(defun cpio-newc-start-of-trailer ()
"Return the character position of the (ostensible) start of the trailer
for the current cpio archive."
(let ((fname "cpio-newc-start-of-trailer")
(end-of-contents 0))
(mapc (lambda (ce)
(let ((attrs (cpio-entry-attrs-from-catalog-entry ce)))
(setq end-of-contents (+ (cpio-entry-size attrs) (cpio-contents-start ce)))))
*cpio-catalog*)
end-of-contents))
(defun cpio-newc-end-of-archive ()
"Calculate the location of the end of the current archive
once the TRAILER is written and padded."
(let ((fname "cpio-newc-end-of-archive")
(end-of-contents (cpio-newc-start-of-trailer)))
(cg-round-up (+ end-of-contents (length *cpio-newc-trailer*)) *cpio-newc-blocksize*)))
(defun cpio-newc-adjust-trailer ()
"Replace thed current trailer in the current cpio newc archive."
(let ((fname "cpio-newc-adjust-trailer"))
(cpio-newc-delete-trailer)
(cpio-newc-insert-trailer)))
(defun cpio-newc-insert-trailer ()
"Insert a newc trailer into a cpio archive."
(let* ((fname "cpio-newc-insert-trailer")
(base-len (length *cpio-newc-trailer*))
(len))
;; ...and insert the new trailer...
(with-writable-buffer
(insert *cpio-newc-trailer*)
(goto-char (point-max))
;; ...with padding.
(setq len (cg-round-up (1- (point)) *cpio-newc-blocksize*))
(setq len (1+ (- len (point))))
(insert (make-string len ?\0)))))
(defun cpio-newc-delete-trailer ()
"Delete the trailer in the current cpio newc archive."
(let ((fname "cpio-newc-delete-trailer"))
(unless (eq major-mode 'cpio-mode)
(error "%s(): Called outside of a cpio archive buffer." fname))
;; First, get to the end of the last entry in the archive.
(goto-char (point-min))
(mapc (lambda (e)
(let* ((ename (car e)) ;Isn't there a generic function for this?
(attrs (cpio-entry-attrs ename))
;; Fencepost issue here.
(entry-end (+ (cpio-contents-start ename)
(cpio-entry-size attrs))))
(goto-char entry-end)
(skip-chars-forward "\0")))
*cpio-catalog*)
;; Next, delete what's left...
(with-writable-buffer
(delete-region (point) (point-max)))))
(defun cpio-newc-make-chksum-for-file (filename)
"Return the checksum for FILENAME."
(let ((fname "cpio-newc-make-chksum-for-file")
)
;; (error "%s() is not yet implemented" fname)
0
))
;;
;; Test and other development assistance.
;;
(defun cpio-newc-present-header (header-string)
"Parse the HEADER-STRING and present its fields nicely.
That is show their names and octal and decimal values."
(let ((fname "cpio-newc-present-header")
(header-contents (cpio-newc-parse-header header-string))
(header-fields (list "magic"
"ino"
"mode"
"uid"
"gid"
"nlink"
"mtime"
"filesize"
"dev-maj"
"dev-min"
"rdev-maj"
"rdev-min"
"namesize"
"chksum"
"name")))
(apply #'concat (cl-mapcar (lambda (name value)
(setq name name)
;; (cg-pad-right name 12 " "))
(format "%s\t%s\t%o\t%d\n"
name
(cg-pad-right value 8 " ")
(string-to-number value 16)
(string-to-number value 16)))
header-fields header-contents))))
(defconst *locations-delay* 0.05 ;FIXME: Namespace!
"The number of seconds to wait at certain points in M-x locations.")
(defun locations () ;FIXME: Namespace!
"Put locations and location related data into the buffer *Locations*.
This is not done properly; it is somewhat brute force.
However, it is intended to help figure out
what the proper way to do it is."
(interactive)
(let ((fname "locations")
(lbuf (get-buffer-create "*Locations*"))
(name)
(namesize 0)
(soh)
(sofn)
(eoh)
(eon)
(hpad)
(filesize 0)
(soc)
(eoc)
(cpad)
(name "")
(ct 0)
(interval 0))
(unless (and lbuf
(buffer-live-p lbuf))
(error "Could not get buffer *Locations*."))
(with-current-buffer lbuf (erase-buffer))
(goto-char (point-min))
(while (re-search-forward *cpio-newc-header-re* (point-max) t)
(goto-char (match-beginning 0))
(sit-for *locations-delay*)
(setq soh (point))
(save-match-data
(looking-at *cpio-newc-magic*)
(goto-char (match-end 0)))
(forward-char (+ 8 ;inode
8 ;mode
8 ;uid
8 ;gid
8 ;nlink
8)) ;mtime
(sit-for *locations-delay*)
(setq filesize (string-to-number (buffer-substring-no-properties (point) (+ (point) 8))))
(forward-char (+ 8 ;filesize
8 ;dev-maj
8 ;dev-min
8 ;rdev-maj
8)) ;rdev-min
;namesize
(sit-for *locations-delay*)
;; HEREHERE
(setq namesize (string-to-number (buffer-substring-no-properties (point) (+ (point) 8))))
(forward-char (+ 8 ;namesize
8)) ;chksum
(sit-for *locations-delay*)
(setq sofn (point))
(sit-for *locations-delay*)
(setq name (buffer-substring-no-properties (point) (+ (point) namesize -1)))
(sit-for *locations-delay*)
(setq eoh (point))
(forward-char namesize)
(setq eon (point))
(setq hpad (skip-chars-forward "\0"))
(setq soc (point))
(re-search-forward "\0\\|070701" (point-max) t)
(goto-char (match-beginning 0))
(sit-for *locations-delay*)
(setq eoc (point))
(sit-for *locations-delay*)
(setq cpad (skip-chars-forward "\0"))
(with-current-buffer lbuf
(funcall 'insert-table-header-maybe ct)
(insert (format (concat "%5s\t" ;Name
" %5d\t" ;Name length
" %5d\t" ;SOH
" %5d\t" ;SOFN
" %5d\t" ;EOH
" %5d\t" ;EON
" %5d\t" ;hpad
" %5d\t" ;File size
" %5d\t" ;SOC
" %5d\t" ;EOC
" %5d\t" ;cpad
"\n")
name
namesize
soh
sofn
eoh
eon
hpad
filesize
soc
eoc
cpad)))
(setq ct (1+ ct)))
(with-current-buffer lbuf
(goto-char (point-max))
(insert (concat "Notes: 1. Name length includes the terminating NULL.\n"
" 2. SOH is calculated via a search for the magic number.\n"
" 3. EOH and SON are equal; each calculation is via the point.\n"
" 4. hpad and cpad are each calculated by motion.\n"))
(goto-char (point-min)))
(pop-to-buffer lbuf)))
(defun insert-table-header-maybe (ct) ;FIXME: Namespace!
"Insert a table header for a cpio entry."
(let ((fname "insert-table-header-maybe"))
(message "%s(): ct is [[%s]]" fname ct) (sit-for .2)
(cond ((= 0 (mod ct 40))
(insert "\n")
(insert (concat " Name\t"
" Name\t"
" SOH\t"
" SOFN\t"
" EOH\t"
" EON\t"
" hpad\t"
" File\t"
" SOC\t"
" EOC\t"
" cpad"
"\n"))
(insert "\tlength\t\t\t\t\t\t size\t\t\t\n")
(insert (concat
(make-string 8 ?=) ;name
(make-string 8 ?=) ;name length
(make-string 8 ?=) ;SOH
(make-string 8 ?=) ;SOFN
(make-string 8 ?=) ;EOH
(make-string 8 ?=) ;EON
(make-string 8 ?=) ;hpad
(make-string 8 ?=) ;File size
(make-string 8 ?=) ;SOC
(make-string 8 ?=) ;EOC
(make-string 8 ?=) ;cpad
(make-string 8 ?=) ;????
"\n")))
(t t))))
(provide 'cpio-newc)
;;; cpio-newc.el ends here.