Get Stock Information Code

#!/bin/sh
#\
exec tclsh "$0" "$@"

# gesi: get stock information
# Copyright (C) 2000  Luis F. Guzmán
#
#      e-mail: luis.guzman@att.net
#
# 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 2
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#

set msg \
  "Usage: gesi ?-s? ?-l? ?-d? ?-t? ?-c? ?-o? ?-h? ?-g? ?-v? symbol ?symbol...?
     where:
       s = stock symbol
       l = last price
       d = last price date
       t = last price time
       c = change since yesterday
       o = open
       h = high for today
       g = low for today
       v = volume"

set HEADER_LINES 4

set options "sl1d1t1c1ohgv"   ;# default options

# if customized options, get them
set or "false"   ;# options variable has not been reset
while {$argc > 0 && [string range [lindex $argv 0] 0 0] == "-"} {
    if {$or == "false"} {
        set options ""
        set or "true"
    }
    switch [string range [lindex $argv 0] 1 1] {
        s {append options "s"}
        p {append options "l1"}
        d {append options "d1"}
        t {append options "t1"}
        c {append options "c1"}
        o {append options "o"}
        h {append options "h"}
        l {append options "g"}
        v {append options "v"}
        default {
            puts "gesi ERROR: invalid argument!"
            puts $msg
            exit
        }
    }
    set argv [lreplace $argv 0 0]
    set argc [expr $argc - 1]
}

if {$argc < 1} {   ;# there has to be at least one stock symbol
    puts $msg
    exit
}

# get stock symbols
set first "true"
while {$argc > 0} {
    if {$first == "true"} {
        set first "false"
    } else {
        append sym "+"
    }
    append sym [lindex $argv 0]

    set argv [lreplace $argv 0 0]
    set argc [expr $argc - 1]
}

set sym [string toupper $sym]

if {[catch {socket quote.yahoo.com 80} so]} {   ;# connect to server
    puts "(gesi)ERROR: couldn't open socket: host is unreachable!"
    exit -1
}

set q "/d/quotes.csv?s=$sym&f=$options"   ;# construct query str

puts $so "GET $q HTTP/1.0\n\n"            ;# send request
flush $so

set i 0
while {1} {
    gets $so line
    if {[eof $so]} {   ;# don't print the last blank line
        exit
    } elseif {[expr $i > $HEADER_LINES] && ![regexp {^$} $line]} {  ;# or header
        puts $line
    }
    incr i
}