POSIX準拠のシェルスクリプトでハッシュ値を計算する（FNV-1 / FNV-1a実装）

packagemainimport("os""fmt""hash/fnv""io/ioutil")funcfnv1(b[]byte)uint32{h:=fnv.New32()h.Write(b)returnh.Sum32()}funcfnv1a(b[]byte)uint32{h:=fnv.New32a()h.Write(b)returnh.Sum32()}funcmain(){data,err:=ioutil.ReadAll(os.Stdin)iferr!=nil{fmt.Println("err",err)os.Exit(1)}fmt.Printf("%x\n",fnv1(data))fmt.Printf("%x\n",fnv1a(data))}

$cat data.dat | hexdump -C00000000  48 65 6c 6c 6f 20 57 6f  72 6c 64 0a              |Hello World.|
0000000c

$go build fnv.go
$fnv < data.dat
12a9a437
d8ea85d7
#上がfnv1、下がfnv1a

[$((010))-eq 8 ]&&OCT="0"||OCT="8#"if od-A n -t o1 -v /dev/null >/dev/null 2>&1;then
  od_command(){od-A n -t o1 -v;}elif hexdump -e'16/1 " %03o" "\n"'-v /dev/null >/dev/null 2>&1;then
  od_command(){ hexdump -e'16/1 " %03o" "\n"'-v;}elif od-b-v /dev/null >/dev/null 2>&1;then
  od_command(){od-b-v | while IFS=" "read-r o o;do echo"$o";done;}else
  echo"od command not found">&2
  exit 1
fi

read_as_binary(){
  od_command | {while IFS=read-r line;do
      eval"$1$line"done"$2"}}

# 詳細は「バイナリデータの扱い」参照[$((010))-eq 8 ]&&OCT="0"HEX="0x"||OCT="8#"HEX="16#"

fnv1(){for oct;do
    hash=$(((($hash*$FNV_PRIME_32)&${HEX}FFFFFFFF)^${OCT}$oct));done}

fnv1a(){for oct;do
    hash=$(((($hash^${OCT}$oct)*$FNV_PRIME_32)&${HEX}FFFFFFFF ))done}

finished(){printf"%8x\n"$hash}FNV_OFFSET_BASIS_32=2166136261
FNV_PRIME_32=16777619

hash=$FNV_OFFSET_BASIS_32
read_as_binary fnv1 finished < data.dat
# => 12a9a437hash=$FNV_OFFSET_BASIS_32
read_as_binary fnv1a finished < data.dat
# => d8ea85d7# 注意 zsh を除く シェルは NULL 文字 (\0) を変数に入れられないのでデータ(data.dat)に# NULL 文字が含まれていないと保証できない場合はデータを変数に入れることは出来ません# data.dat を 2 回読み込んでるのはそのためです

finished(){if["$hash"-lt 0 ];then
    printf"%4x%4x\n"$((($hash>>16)&${HEX}FFFF ))$(($hash&${HEX}FFFF ))else
    printf"%8x\n"$hashfi}

# 値が変わっている
ksh -c'echo $((111111111111111111))'
111111111111111104

# 変数に入れればいけるか思いきや計算するとだめ
ksh -c'a=111111111111111111; echo $((a))'
111111111111111111
ksh -c'a=111111111111111111; echo $((a+0))' 
111111111111111104

# typeset -iで整数型にしてもだめ$ ksh -c'typeset -i a=123456789012345; typeset i=10; typeset -i a=$((a*i)); echo $a'-2147483648$ mksh -c'typeset -i a=123456789012345; typeset i=10; typeset -i a=$((a*i)); echo $a'
1015724730

[$((010))-eq 8 ]&&OCT="0"||OCT="8#"if od-A n -t o1 -v /dev/null >/dev/null 2>&1;then
  od_command(){od-A n -t o1 -v;}elif hexdump -e'16/1 " %03o" "\n"'-v /dev/null >/dev/null 2>&1;then
  od_command(){ hexdump -e'16/1 " %03o" "\n"'-v;}elif od-b-v /dev/null >/dev/null 2>&1;then
  od_command(){od-b-v | while IFS=" "read-r o o;do echo"$o";done;}else
  echo"od command not found">&2
  exit 1
fi

read_as_binary(){
  od_command | {while IFS=read-r line;do
      eval"$1$line"done"$2"}}

fnv1(){for oct;do
    hash=$((((((($hash>>16)*$FNV_PRIME_32)&65535)<< \ 16)+(($hash&65535)*$FNV_PRIME_32))&4294967295))hash=$(($hash^${OCT}$oct))done}

fnv1a(){for oct;do
    hash=$(($hash^${OCT}$oct))hash=$((((((($hash>>16)*$FNV_PRIME_32)&65535)<< \16)+(($hash&65535)*$FNV_PRIME_32))&4294967295))done}

finished(){if[$hash-lt 0 ];then
    printf"%4x%4x\n"$((($hash>>16)&65535))$(($hash&65535))else
    printf"%8x\n"$hashfi}FNV_OFFSET_BASIS_32=2166136261
FNV_PRIME_32=16777619

hash=$FNV_OFFSET_BASIS_32
read_as_binary fnv1 finished < data.dat
# => 12a9a437hash=$FNV_OFFSET_BASIS_32
read_as_binary fnv1a finished < data.dat
# => d8ea85d7