From 46709093bea8d12c0ef4a8f6401be8f5856b466b Mon Sep 17 00:00:00 2001
From: Michael Albinus <michael.albinus@gmx.de>
Date: Tue, 25 Aug 2015 16:05:21 +0200
Subject: [PATCH] * lisp/net/tramp-sh.el (tramp-awk-encode, tramp-awk-decode)

(tramp-awk-coding-test): New defconsts.
(tramp-remote-coding-commands): Use them.
(tramp-find-inline-encoding): Check for Perl only if necessary.
---
 lisp/net/tramp-sh.el | 73 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 71 insertions(+), 2 deletions(-)

diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 3239107e8b3..9bd22d27d5d 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -873,6 +873,72 @@ Escape sequence %s is replaced with name of Perl binary.")
   "Perl program to use for decoding a file.
 Escape sequence %s is replaced with name of Perl binary.")
 
+(defconst tramp-awk-encode
+  "od -v -t x1 -A n | busybox awk '\\
+BEGIN {
+  b64 = \"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\"
+  b16 = \"0123456789abcdef\"
+}
+{
+  for (c=1; c<=length($0); c++) {
+    d=index(b16, substr($0,c,1))
+    if (d--) {
+      for (b=1; b<=4; b++) {
+        o=o*2+int(d/8); d=(d*2)%%16
+        if (++obc==6) {
+          printf substr(b64,o+1,1)
+          if (++rc>75) { printf \"\\n\"; rc=0 }
+          obc=0; o=0
+        }
+      }
+    }
+  }
+}
+END {
+  if (obc) {
+    tail=(obc==2) ? \"==\\n\" : \"=\\n\"
+    while (obc++<6) { o=o*2 }
+    printf \"%%c\", substr(b64,o+1,1)
+  } else {
+    tail=\"\\n\"
+  }
+  printf tail
+}'"
+  "Awk program to use for encoding a file.
+This string is passed to `format', so percent characters need to be doubled.")
+
+(defconst tramp-awk-decode
+  "busybox awk '\\
+BEGIN {
+  b64 = \"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\"
+}
+{
+  for (i=1; i<=length($0); i++) {
+    c=index(b64, substr($0,i,1))
+    if(c--) {
+      for(b=0; b<6; b++) {
+        o=o*2+int(c/32); c=(c*2)%%64
+        if(++obc==8) {
+          if (o) {
+            printf \"%%c\", o
+          } else {
+            system(\"dd if=/dev/zero bs=1 count=1 2>/dev/null\")
+          }
+          obc=0; o=0
+        }
+      }
+    }
+  }
+}'"
+  "Awk program to use for decoding a file.
+This string is passed to `format', so percent characters need to be doubled.")
+
+(defconst tramp-awk-coding-test
+  "test -c /dev/zero && \
+od -v -t x1 -A n </dev/null && \
+busybox awk '{}' </dev/null"
+  "Test command for checking `tramp-awk-encode' and `tramp-awk-decode'.")
+
 (defconst tramp-stat-marker "/////"
   "Marker in stat commands for file attributes.")
 
@@ -4245,7 +4311,7 @@ and end of region, and are expected to replace the region contents
 with the encoded or decoded results, respectively.")
 
 (defconst tramp-remote-coding-commands
-  '((b64 "base64" "base64 -d -i")
+  `((b64 "base64" "base64 -d -i")
     ;; "-i" is more robust with older base64 from GNU coreutils.
     ;; However, I don't know whether all base64 versions do supports
     ;; this option.
@@ -4255,6 +4321,8 @@ with the encoded or decoded results, respectively.")
     (b64 "recode data..base64" "recode base64..data")
     (b64 tramp-perl-encode-with-module tramp-perl-decode-with-module)
     (b64 tramp-perl-encode tramp-perl-decode)
+    ;; This is painful slow, so we put it on the end.
+    (b64 tramp-awk-encode tramp-awk-decode ,tramp-awk-coding-test)
     (uu  "uuencode xxx" "uudecode -o /dev/stdout" "test -c /dev/stdout")
     (uu  "uuencode xxx" "uudecode -o -")
     (uu  "uuencode xxx" "uudecode -p")
@@ -4333,7 +4401,8 @@ Goes through the list `tramp-local-coding-commands' and
 		    (unless (tramp-send-command-and-check vec rem-test t)
 		      (throw 'wont-work-remote nil)))
 		  ;; Check if remote perl exists when necessary.
-		  (when (and (not (stringp rem-enc))
+		  (when (and (symbolp rem-enc)
+			     (string-match "perl" (symbol-name rem-enc))
 			     (not (tramp-get-remote-perl vec)))
 		    (throw 'wont-work-remote nil))
 		  ;; Check if remote encoding and decoding commands can be
-- 
2.39.5