mdw@git.distorted.org.uk Git - sgt/utils/blob - nntpid/nntpid

   1 #!/usr/bin/perl
   2 #
   3 # Script to retrieve a single article from a news server, either by
   4 # message-id or by group name and article number.
   5 #
   6 # Usage:     nntpid <messageid>
   7 #    or:     nntpid messageid               (angle brackets optional)
   8 #    or:     nntpid news.group.name 1234    (group+number form)
   9 #    or:     nntpid -a news.group.name      (download all available articles)
  10 #
  11 # The name of your news server is obtained from the environment variable
  12 # NNTPSERVER, or from the file /etc/nntpserver if that's not set.
  13 #
  14 # This script supports AUTHINFO GENERIC authentication using the
  15 # environment variable NNTPAUTH. It will only attempt this if it receives
  16 # a 480 response from the news server; if your news server isn't paranoid
  17 # then the script will never need to look at NNTPAUTH.
  18
  19 # Copyright 2000,2004 Simon Tatham. All rights reserved.
  20
  21 require 5.002;
  22 use Socket;
  23 use FileHandle;
  24
  25 $usage =
  26   "usage: nntpid [ -v ] [ -d ] <message-id>\n" .
  27   "   or: nntpid [ -v ] [ -d ] <newsgroup> <article-number>\n" .
  28   "   or: nntpid [ -v ] -a <newsgroup>\n" .
  29   "where: -v                  verbose (print interaction with news server)\n" .
  30   "       -d                  direct output (don't consider using PAGER)\n" .
  31   "       -a                  dump all articles in group to stdout as mbox\n" .
  32   " also: nntpid --version    report version number\n" .
  33   "       nntpid --help       display this help text\n" .
  34   "       nntpid --licence    display (MIT) licence text\n";
  35
  36 $licence =
  37   "nntpid is copyright 2000,2004 Simon Tatham.\n" .
  38   "\n" .
  39   "Permission is hereby granted, free of charge, to any person\n" .
  40   "obtaining a copy of this software and associated documentation files\n" .
  41   "(the \"Software\"), to deal in the Software without restriction,\n" .
  42   "including without limitation the rights to use, copy, modify, merge,\n" .
  43   "publish, distribute, sublicense, and/or sell copies of the Software,\n" .
  44   "and to permit persons to whom the Software is furnished to do so,\n" .
  45   "subject to the following conditions:\n" .
  46   "\n" .
  47   "The above copyright notice and this permission notice shall be\n" .
  48   "included in all copies or substantial portions of the Software.\n" .
  49   "\n" .
  50   "THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND,\n" .
  51   "EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF\n" .
  52   "MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND\n" .
  53   "NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS\n" .
  54   "BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN\n" .
  55   "ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN\n" .
  56   "CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE\n" .
  57   "SOFTWARE.\n";
  58
  59 $pager = 1;
  60 $verbose = 0;
  61 $all = 0;
  62
  63 while ($ARGV[0] =~ /^-(.+)$/) {
  64   shift @ARGV;
  65   $verbose = 1, next if $1 eq "v";
  66   $pager = 0, next if $1 eq "d";
  67   $all = 1, next if $1 eq "a";
  68   if ($1 eq "-help") {
  69     print STDERR $usage;
  70     exit 0;
  71   } elsif ($1 eq "-version") {
  72     if ('$Revision$' =~ /Revision:\s+(\d+)/) {
  73         print "nntpid revision $1\n";
  74     } else {
  75         print "nntpid: unknown revision\n";
  76     }
  77     exit 0;
  78   } elsif ($1 eq "-licence" or $1 eq "-license") {
  79     print $licence;
  80     exit 0;
  81   }
  82 }
  83
  84 die $usage if !defined $ARGV[0];
  85
  86 if ($all) {
  87   $group = $ARGV[0];
  88 } elsif (defined $ARGV[1]) {
  89   $group = $ARGV[0];
  90   $mid = $ARGV[1];
  91 } else {
  92   $group = "misc.misc";
  93   $mid = $ARGV[0];
  94   $mid =~ s/^<//;
  95   $mid =~ s/>$//;
  96   $mid = "<$mid>";
  97 }
  98
  99 $ns=$ENV{'NNTPSERVER'};
 100 if (!defined $ns or !length $ns) {
 101   $ns = `cat /etc/nntpserver`;
 102   chomp $ns;
 103 }
 104 $port = (getservbyname("nntp", "tcp"))[2];
 105 $ns = inet_aton($ns);
 106 $proto = getprotobyname("tcp");
 107 $paddr = sockaddr_in($port, $ns);
 108
 109 socket(S,PF_INET,SOCK_STREAM,$proto) or die "socket: $!";
 110 connect(S,$paddr) or die "connect: $!";
 111
 112 S->autoflush(1);
 113
 114 $fatal = 1; # most errors need to be fatal
 115
 116 &getline;
 117 $code =~ /^2\d\d/ or die "no initial greeting from server\n";
 118
 119 &docmd("MODE READER");
 120 # some servers require a GROUP before an ARTICLE command
 121 $numbers = &docmd("GROUP $group");
 122 if ($all) {
 123     @numbers = split / /, $numbers;
 124     $fatal = 0; # ignore failure to retrieve any given article
 125     for ($mid = $numbers[1]; $mid <= $numbers[2]; $mid++) {
 126         $art = &getart($mid);
 127         $art =~ s/\n(>*From )/\n>$1/gs;
 128         print "From nntpid ".(localtime)."\n".$art."\n";
 129     }
 130 } else {
 131     $art = &getart($mid);
 132     &docmd("QUIT");
 133     close S;
 134
 135     if ($pager and -t STDOUT) {
 136         $pagername = $ENV{"PAGER"};
 137         $pagername = "more" unless defined $pagername;
 138         open PAGER, "| $pagername";
 139         print PAGER $art;
 140         close PAGER;
 141     } else {
 142         print $art;
 143     }
 144 }
 145
 146 sub getart {
 147   my ($mid) = @_;
 148   $ret = &docmd("ARTICLE $mid");
 149   return undef if !defined $ret;
 150   $art = "";
 151   while (1) {
 152     &getline;
 153     s/[\r\n]//g;
 154     last if /^\.$/;
 155     s/^\.//;
 156     $art .= "$_\n";
 157   }
 158   return $art;
 159 }
 160
 161 sub putline {
 162   my ($line) = @_;
 163   print STDERR ">>> $line\n" if $verbose;
 164   print S "$line\r\n";
 165 }
 166
 167 sub getline {
 168   $_ = <S>;
 169   s/[\r\n]*$//s;
 170   $code = substr($_,0,3);
 171   print STDERR "<<< $_\n" if $verbose;
 172   return substr($_,4);
 173 }
 174
 175 sub docmd {
 176   my ($cmd) = @_;
 177   # We go at most twice round the following loop. If the first attempt
 178   # to fetch the article fails with a 480 response, we try again
 179   # having authenticated first; but if the second attempt also fails
 180   # with 480, then the authentication didn't work, so we should give
 181   # up rather than try it pointlessly again.
 182   for my $n (0,1) {
 183     &putline($cmd);
 184     $line = &getline;
 185     if ($code eq "480") { &auth; } else { last; }
 186   }
 187   if ($code !~ /^2\d\d/) {
 188     die "failed on `$cmd':\n$_\n" if $fatal;
 189     return undef;
 190   }
 191   return $line;
 192 }
 193
 194 sub auth {
 195   # Authentication.
 196   if ($ENV{"NNTPAUTH"}) {
 197     $auth = $ENV{"NNTPAUTH"};
 198     &putline("AUTHINFO GENERIC $auth");
 199     pipe AUTHSTDIN, TOAUTH or die "unable to create pipes";
 200     pipe FROMAUTH, AUTHSTDOUT or die "unable to create pipes";
 201     $pid = fork;
 202     if (!defined $pid) {
 203       die "unable to fork for authentication helper";
 204     } elsif ($pid == 0) {
 205       # we are child
 206       $ENV{"NNTP_AUTH_FDS"} = "0.1";
 207       open STDIN, "<&AUTHSTDIN";
 208       open STDOUT, ">&AUTHSTDOUT";
 209       close S;
 210       exec $auth;
 211     }
 212     # we are parent
 213     close AUTHSTDIN;
 214     close AUTHSTDOUT;
 215     autoflush TOAUTH 1;
 216     &getline; print TOAUTH "$_\n";
 217     while (<FROMAUTH>) {
 218       s/[\r\n]*$//s;
 219       &putline($_);
 220       &getline;
 221       print TOAUTH "$_\n";
 222     }
 223     die "failed authentication\n" unless $? == 0;
 224   }
 225 }