examples/scripts.noah/send_mail.bash

   1 # send_mail.bash
   2 # Author: Noah Friedman <friedman@prep.ai.mit.edu>
   3 # Created: 1992-07-02
   4 # Public domain
   5
   6 # Commentary:
   7
   8 # TODO: implement Fcc headers (see emacs manual)
   9
  10 # Code:
  11
  12 #:docstring send_mail:
  13 # Usage: send_mail
  14 #
  15 # This function serves as a simple replacement for sendmail as a client
  16 # interface on those systems where it is not available.  It does assume
  17 # that one can talk to an SMTP mailer on port 25 either on the local host
  18 # or on the host specified by the MAILHOST environment variable.  If you
  19 # have access to sendmail, it's better to use 'sendmail -t' instead of this
  20 # script (which probably isn't as robust).
  21 #
  22 # Message is read from stdin, and headers are parsed to determine
  23 # recipients.
  24 #:end docstring:
  25
  26 ###;;;autoload
  27 function send_mail ()
  28 {
  29     # Need gawk, since several extensions are taken advantage of (like
  30     # IGNORECASE for regexps).
  31     local awk="${GAWK_LOCATION:-gawk}"
  32     local DefaultFrom="${USER:-${LOGNAME}}"
  33     local From
  34     local To
  35     local Cc
  36     local Bcc
  37     local tmpfile="/tmp/send_mail$$"
  38
  39     while [ -e "${tmpfile}" ]; do
  40        tmpfile="/tmp/send_mail${RANDOM}"
  41     done
  42
  43     # Lines consisting only of dots need one more dot appended.  SMTP
  44     # servers eat one of the dots (and if only 1 dot appears, it signifies
  45     # the end of the message).
  46     sed '/^\.\.*/s/^\(\.\.*\)$/\1./' > "${tmpfile}"
  47
  48     # Parse mail headers in message to extract recipients list.
  49     # This doesn't affect what the user sees---it's only used to generate
  50     # the rcpt-to lines for SMTP.
  51     eval $(${awk} -f - "${tmpfile}" <<- '__EOF__'
  52        # Try to extract email address from amidst random data
  53        function parse_address (data)
  54        {
  55            # From: "real name" <foobar@host>
  56            # From: "" <foobar@host>
  57            if (match(data, /^\"[^\"]*\"[ \t]*<.*>/)) {
  58               data_idx = match(data, /^\"[^\"]*\"[ \t]*</)
  59               data = substr(data, RSTART + RLENGTH);
  60               if (data_idx = match(data, ">.*"))
  61                  data = substr(data, 1, RSTART - 1);
  62               return data
  63            }
  64            # From: real name <foobar@host>
  65            if (match(data, /<.*>/)) {
  66               data_idx = match(data, /</)
  67               data = substr(data, RSTART + RLENGTH);
  68               if (data_idx = match(data, ">"))
  69                  data = substr(data, 1, RSTART - 1);
  70               return data
  71            }
  72            # From: foobar@host (real name)
  73            if (match(data, /\(.*\)/)) {
  74               data_idx = match(data, /\(/);
  75               data = substr(data, 1, RSTART - 1);
  76               return data
  77            }
  78            # (hopefully) From: foobar@host
  79            return data
  80        }
  81
  82        BEGIN { IGNORECASE = 1; }
  83
  84        # Blank line signifies end of headers, so we can stop looking.
  85        /^$/ { exit(0) }
  86
  87        /^from:|^to:|^cc:|^bcc:/ {
  88           header_idx = match($0, /^[^:]*:/)
  89           if (header_idx) {
  90              # Capitalize header name
  91              header_firstchar = toupper(substr($0, RSTART, 1));
  92              header_rest = tolower(substr($0, RSTART + 1, RLENGTH - 2));
  93              header = header_firstchar header_rest
  94
  95              $0 = substr($0, RSTART + RLENGTH + 1);
  96              addresses = ""
  97              # parse addresses
  98              while ($0) {
  99                 # Strip leading whitespace
 100                 if (idx = match($0, /[ \t]*/))
 101                    $0 = substr($0, RSTART + RLENGTH);
 102
 103                 # Find everything up to a nonquoted comma
 104                 # FIXME: doesnt handle quoting yet
 105                 if (idx = match($0, /,/)) {
 106                    data = substr($0, 1, RSTART);
 107                    $0 = substr($0, RSTART + 1);
 108                 } else {
 109                    data = $0
 110                    $0 = ""
 111                 }
 112                 addresses = addresses " " parse_address(data)
 113              }
 114
 115              printf("%s='%s'\n", header, addresses);
 116           }
 117        }
 118         __EOF__)
 119
 120     # Not sure if an address is *required* after the HELO.. every sendmail
 121     # I tried talking to didn't seem to care.  Some sendmails don't care
 122     # if there's a HELO at all.
 123     cat <<- __EOF__ | telnet ${MAILHOST:-localhost} 25 > /dev/null 2>&1
 124         HELO
 125         mail from: ${From:-${DefaultFrom}}
 126         $(for name in ${To} ${Cc} ${Bcc} ; do
 127              echo "rcpt to: ${name}"
 128           done)
 129         data
 130         $(cat "${tmpfile}")
 131         .
 132         quit
 133         __EOF__
 134
 135     rm -f "${tmpfile}"
 136 }
 137
 138 provide send_mail
 139
 140 # send_mail.bash ends here