101914

  echoe(){ local a=${#1}; echo $1 |dd bs=1 count=$a;}

  Substitute "learnenough.com/command-line" for "conqueringthecommandline.com/book"
 

  Go to conqueringthecommandline.com/book
  Save the page source
  Insert the filename into the script below
  Alternatively, omit filename and pipe the source of the page to the script 

  Works with BSD sed as well as GNU sed; first lesson: portability

   a=$(printf '\004')
   sed 's/s3_url/'"$a"'&/' \
   |tr '\004' '\012' \
   |exec sed '
   s/\\u0026/\&/g;
   s/.*s3_url.:.//g;
   s/\".*//g;
   /https:.*Amz/!d;
   ' filename

  # requirements:
  # sh, sed (BSD ok), tr, openssl, ftp or some other httpclient

  curl=ftp 
  file=${2-1.mp4} # default outfile

  # itag #s are on the wikipedia page for youtube

  case $# in
  [12])
  {
  sed 's/http:/https:/' \
  |while read a;
  do

  b=${a#*://}; 
  c=${b%%/*}; 
  {
  printf "%b" "GET /${a#https://*/} HTTP/1.0\r\n";
  printf "Host: $c\r\n";
  printf "User-Agent: OK, Google.\r\n";
  printf "Connection: close\r\n\r\n";
  } \
  |openssl s_client -ign_eof -connect $c:443 -verify 9 
  done \
  |sed '
  s,http,\
  &,g;
  ' \
  |sed '
  /%3A%2F/!d;
  /videoplayback/!d; 
  s,%3D,=,g;
  s,%3A,:,g;
  s,%2F,/,g;
  s,%3F,?,g;
  s/^M//g;
  ' \
  |sed -e '
  s/&itag=5//;t1
  s/&itag=1[78]//;t1
  s/&itag=22//;t1
  s/&itag=3[4-8]//;t1
  s/&itag=4[3-6]//;t1
  s/&itag=1[346][0-9]//;t1
  ' -e :1 \
  |sed '
  s,%26,\
  ,g;
  s,&,\
  ,g;
  ' \
  |sed 's/%25/%/g' \
  |tr '\012' '&' \
  |sed 's/&$//'; 
  echo 
  } \
  |sed '
  s,%3D,=,g;
  s,%3A,:,g;
  s,%2F,/,g;
  s,%3F,?,g;
  s/^M//g;
  ' \
  |sed '
  s/&https/\
  \
  https/g;' \
  |sed 's/\\u0026.*//' \
  |sed '/itag='"${1-.}"'/!d;'|{ 
  read a;
  exec $curl -4o $file $a;}
  ;;
  *)
  exec echo \
  "usage:   $0 itagno [outfile]
  outfile: $file"
  esac

  a=$(printf '\xb%-47.s' \
  |nc -uw1 ntp.metas.ch 123 \
  |exec xxd -s40 -l4 -p) 
  b=$(printf %d\\n 0x"$a")
  c=$((b-2208988800))
  date -r$c

   # proof of concept: video retrieval
   
   # requirements:
   # sh, sed, tr, openssl, ftp
   
   # Adobe Flash not required
   # HTML5 not required
   # Python not required
   # Awk not required
   # web browser not required
   
   
   curl=ftp 
   file=1.mp4 # default outfile 
   url=www.youtube.com # example
   
   
   # itag #s are on the wikipedia page for youtube
   
   
   
   f061(){
   sed '
   s,%3D,=,g;
   s,%3A,:,g;
   s,%2F,/,g;
   s,%3F,?,g;
   s/

   f060(){
   sed -e '
   s/&itag=5//;t1
   s/&itag=1[78]//;t1
   s/&itag=22//;t1
   s/&itag=3[4-8]//;t1
   s/&itag=4[3-6]//;t1
   s/&itag=1[346][0-9]//;t1
   ' -e :1
   }
   
   f062(){
   sed '
   s,http,\
   &,g' 
   }
   
   f063(){
   sed '
   /%3A%2F/!d;
   /videoplayback/!d' 
   }
   
   f064(){
   sed '
   s,%26,\
   ,g;
   s,&,\
   ,g;
   ' 
   }
   
   f065(){
   sed 's/&https/\
   \
   https/g;' 
   }
   
   f066(){
   sed 's/\\u0026.*//' 
   }
   
   f067(){
   sed '/itag='"${1-.}"'/!d;' 
   }
   
   f068(){
   sed 's/%25/%/g' 
   }
   
   
   f069(){
   tr '\012' '&' 
   }
   
   f070(){
   sed 's/&$//'; echo 
   }
   
   f071(){
   local a061 a062 a063;
   while read a; do 
   case $a in 
   https://*)a061=${a#https://*/} ;; 
   http://*)a061=${a#http://*/} ;; 
   *)a061=${a#*/} ;; 
   esac; 
   a062=${a#*://}; 
   a063=${a062%%/*}; 
   printf "%b" "${1-GET} /${a061} HTTP/1.0\r\n" 
   printf "Host: ${a063}\r\n";
   printf "User-Agent: GoogleAnalytics 1.5.1\r\n";
   printf "Connection: Close\r\n";
   printf "\r\n";
   done;
   }
   
   f072(){
   openssl s_client -ign_eof -connect $1:${2-443} -verify 9 
   }
   
   
   
   
   
   
   
   case $# in
   [12])
   {
   f071 \
   |f072 $url \
   |f062 \
   |f063 \
   |f061 \
   |f060 \
   |f064 \
   |f068 \
   |f069 \
   |f070
   } \
   |f061 \
   |f065 \
   |f066 \
   |f067 $1 \
   |{ 
   read a;
   exec $curl -4o ${2-$file} $a ;
   }
   
    ;;
   *)
   exec echo \
   "usage:   $0 itagno [outfile]
   outfile: $file"
   esac