1# cksum.tcl - Copyright (C) 2002 Pat Thoyts <patthoyts@users.sourceforge.net> 2# 3# Provides a Tcl only implementation of the unix cksum(1) command. This is 4# similar to the sum(1) command but the algorithm is better defined and 5# standardized across multiple platforms by POSIX 1003.2/D11.2 6# 7# This command has been verified against the cksum command from the GNU 8# textutils package version 2.0 9# 10# ------------------------------------------------------------------------- 11# See the file "license.terms" for information on usage and redistribution 12# of this file, and for a DISCLAIMER OF ALL WARRANTIES. 13# ------------------------------------------------------------------------- 14# $Id: cksum.tcl,v 1.11 2009/04/21 20:06:19 andreas_kupries Exp $ 15 16package require Tcl 8.2; # tcl minimum version 17 18namespace eval ::crc { 19 variable cksum_version 1.1.3 20 21 namespace export cksum 22 23 variable cksum_tbl [list 0x0 \ 24 0x04C11DB7 0x09823B6E 0x0D4326D9 0x130476DC 0x17C56B6B \ 25 0x1A864DB2 0x1E475005 0x2608EDB8 0x22C9F00F 0x2F8AD6D6 \ 26 0x2B4BCB61 0x350C9B64 0x31CD86D3 0x3C8EA00A 0x384FBDBD \ 27 0x4C11DB70 0x48D0C6C7 0x4593E01E 0x4152FDA9 0x5F15ADAC \ 28 0x5BD4B01B 0x569796C2 0x52568B75 0x6A1936C8 0x6ED82B7F \ 29 0x639B0DA6 0x675A1011 0x791D4014 0x7DDC5DA3 0x709F7B7A \ 30 0x745E66CD 0x9823B6E0 0x9CE2AB57 0x91A18D8E 0x95609039 \ 31 0x8B27C03C 0x8FE6DD8B 0x82A5FB52 0x8664E6E5 0xBE2B5B58 \ 32 0xBAEA46EF 0xB7A96036 0xB3687D81 0xAD2F2D84 0xA9EE3033 \ 33 0xA4AD16EA 0xA06C0B5D 0xD4326D90 0xD0F37027 0xDDB056FE \ 34 0xD9714B49 0xC7361B4C 0xC3F706FB 0xCEB42022 0xCA753D95 \ 35 0xF23A8028 0xF6FB9D9F 0xFBB8BB46 0xFF79A6F1 0xE13EF6F4 \ 36 0xE5FFEB43 0xE8BCCD9A 0xEC7DD02D 0x34867077 0x30476DC0 \ 37 0x3D044B19 0x39C556AE 0x278206AB 0x23431B1C 0x2E003DC5 \ 38 0x2AC12072 0x128E9DCF 0x164F8078 0x1B0CA6A1 0x1FCDBB16 \ 39 0x018AEB13 0x054BF6A4 0x0808D07D 0x0CC9CDCA 0x7897AB07 \ 40 0x7C56B6B0 0x71159069 0x75D48DDE 0x6B93DDDB 0x6F52C06C \ 41 0x6211E6B5 0x66D0FB02 0x5E9F46BF 0x5A5E5B08 0x571D7DD1 \ 42 0x53DC6066 0x4D9B3063 0x495A2DD4 0x44190B0D 0x40D816BA \ 43 0xACA5C697 0xA864DB20 0xA527FDF9 0xA1E6E04E 0xBFA1B04B \ 44 0xBB60ADFC 0xB6238B25 0xB2E29692 0x8AAD2B2F 0x8E6C3698 \ 45 0x832F1041 0x87EE0DF6 0x99A95DF3 0x9D684044 0x902B669D \ 46 0x94EA7B2A 0xE0B41DE7 0xE4750050 0xE9362689 0xEDF73B3E \ 47 0xF3B06B3B 0xF771768C 0xFA325055 0xFEF34DE2 0xC6BCF05F \ 48 0xC27DEDE8 0xCF3ECB31 0xCBFFD686 0xD5B88683 0xD1799B34 \ 49 0xDC3ABDED 0xD8FBA05A 0x690CE0EE 0x6DCDFD59 0x608EDB80 \ 50 0x644FC637 0x7A089632 0x7EC98B85 0x738AAD5C 0x774BB0EB \ 51 0x4F040D56 0x4BC510E1 0x46863638 0x42472B8F 0x5C007B8A \ 52 0x58C1663D 0x558240E4 0x51435D53 0x251D3B9E 0x21DC2629 \ 53 0x2C9F00F0 0x285E1D47 0x36194D42 0x32D850F5 0x3F9B762C \ 54 0x3B5A6B9B 0x0315D626 0x07D4CB91 0x0A97ED48 0x0E56F0FF \ 55 0x1011A0FA 0x14D0BD4D 0x19939B94 0x1D528623 0xF12F560E \ 56 0xF5EE4BB9 0xF8AD6D60 0xFC6C70D7 0xE22B20D2 0xE6EA3D65 \ 57 0xEBA91BBC 0xEF68060B 0xD727BBB6 0xD3E6A601 0xDEA580D8 \ 58 0xDA649D6F 0xC423CD6A 0xC0E2D0DD 0xCDA1F604 0xC960EBB3 \ 59 0xBD3E8D7E 0xB9FF90C9 0xB4BCB610 0xB07DABA7 0xAE3AFBA2 \ 60 0xAAFBE615 0xA7B8C0CC 0xA379DD7B 0x9B3660C6 0x9FF77D71 \ 61 0x92B45BA8 0x9675461F 0x8832161A 0x8CF30BAD 0x81B02D74 \ 62 0x857130C3 0x5D8A9099 0x594B8D2E 0x5408ABF7 0x50C9B640 \ 63 0x4E8EE645 0x4A4FFBF2 0x470CDD2B 0x43CDC09C 0x7B827D21 \ 64 0x7F436096 0x7200464F 0x76C15BF8 0x68860BFD 0x6C47164A \ 65 0x61043093 0x65C52D24 0x119B4BE9 0x155A565E 0x18197087 \ 66 0x1CD86D30 0x029F3D35 0x065E2082 0x0B1D065B 0x0FDC1BEC \ 67 0x3793A651 0x3352BBE6 0x3E119D3F 0x3AD08088 0x2497D08D \ 68 0x2056CD3A 0x2D15EBE3 0x29D4F654 0xC5A92679 0xC1683BCE \ 69 0xCC2B1D17 0xC8EA00A0 0xD6AD50A5 0xD26C4D12 0xDF2F6BCB \ 70 0xDBEE767C 0xE3A1CBC1 0xE760D676 0xEA23F0AF 0xEEE2ED18 \ 71 0xF0A5BD1D 0xF464A0AA 0xF9278673 0xFDE69BC4 0x89B8FD09 \ 72 0x8D79E0BE 0x803AC667 0x84FBDBD0 0x9ABC8BD5 0x9E7D9662 \ 73 0x933EB0BB 0x97FFAD0C 0xAFB010B1 0xAB710D06 0xA6322BDF \ 74 0xA2F33668 0xBCB4666D 0xB8757BDA 0xB5365D03 0xB1F740B4 ] 75 76 variable uid ; if {![info exists uid]} {set uid 0} 77} 78 79# crc::CksumInit -- 80# 81# Create and initialize a cksum context. This is cleaned up when we 82# call CksumFinal to obtain the result. 83# 84proc ::crc::CksumInit {} { 85 variable uid 86 set token [namespace current]::[incr uid] 87 upvar #0 $token state 88 array set state {t 0 l 0} 89 return $token 90} 91 92proc ::crc::CksumUpdate {token data} { 93 variable cksum_tbl 94 upvar #0 $token state 95 set t $state(t) 96 binary scan $data c* r 97 foreach {n} $r { 98 set t [expr {($t << 8) 99 ^ [lindex $cksum_tbl [expr { 100 (($t >> 24) \ 101 ^ ($n & 0xFF)) & 0xFF 102 }]]}] 103 incr state(l) 104 } 105 set state(t) $t 106 return 107} 108 109proc ::crc::CksumFinal {token} { 110 variable cksum_tbl 111 upvar #0 $token state 112 set t $state(t) 113 for {set i $state(l)} {$i > 0} {set i [expr {$i>>8}]} { 114 set t [expr {($t << 8) \ 115 ^ [lindex $cksum_tbl \ 116 [expr {(($t >> 24) ^ $i) & 0xFF}]]}] 117 } 118 unset state 119 return [expr {~$t & 0xFFFFFFFF}] 120} 121 122# crc::Pop -- 123# 124# Pop the nth element off a list. Used in options processing. 125# 126proc ::crc::Pop {varname {nth 0}} { 127 upvar $varname args 128 set r [lindex $args $nth] 129 set args [lreplace $args $nth $nth] 130 return $r 131} 132 133# Description: 134# Provide a Tcl equivalent of the unix cksum(1) command. 135# Options: 136# -filename name - return a checksum for the specified file. 137# -format string - return the checksum using this format string. 138# -chunksize size - set the chunking read size 139# 140proc ::crc::cksum {args} { 141 array set opts [list -filename {} -channel {} -chunksize 4096 \ 142 -format %u -command {}] 143 while {[string match -* [set option [lindex $args 0]]]} { 144 switch -glob -- $option { 145 -file* { set opts(-filename) [Pop args 1] } 146 -chan* { set opts(-channel) [Pop args 1] } 147 -chunk* { set opts(-chunksize) [Pop args 1] } 148 -for* { set opts(-format) [Pop args 1] } 149 -command { set opts(-command) [Pop args 1] } 150 default { 151 if {[llength $args] == 1} { break } 152 if {[string compare $option "--"] == 0} { Pop args ; break } 153 set err [join [lsort [array names opts -*]] ", "] 154 return -code error "bad option \"option\": must be $err" 155 } 156 } 157 Pop args 158 } 159 160 if {$opts(-filename) != {}} { 161 set opts(-channel) [open $opts(-filename) r] 162 fconfigure $opts(-channel) -translation binary 163 } 164 165 if {$opts(-channel) == {}} { 166 167 if {[llength $args] != 1} { 168 return -code error "wrong # args: should be\ 169 cksum ?-format string?\ 170 -channel chan | -filename file | string" 171 } 172 set tok [CksumInit] 173 CksumUpdate $tok [lindex $args 0] 174 set r [CksumFinal $tok] 175 176 } else { 177 178 set tok [CksumInit] 179 while {![eof $opts(-channel)]} { 180 CksumUpdate $tok [read $opts(-channel) $opts(-chunksize)] 181 } 182 set r [CksumFinal $tok] 183 184 if {$opts(-filename) != {}} { 185 close $opts(-channel) 186 } 187 } 188 189 return [format $opts(-format) $r] 190} 191 192# ------------------------------------------------------------------------- 193 194package provide cksum $::crc::cksum_version 195 196# ------------------------------------------------------------------------- 197# Local variables: 198# mode: tcl 199# indent-tabs-mode: nil 200# End: 201