private Decimal Unpack(byte[] inp, int scale)
{
long lo = 0;
long mid = 0;
long hi = 0;
bool isNegative;
// this nybble stores only the sign, not a digit.
// "C" hex is positive, "D" hex is negative, and "F" hex is unsigned.
switch (nibble(inp, 0))
{
case 0x0D:
isNegative = true;
break;
case 0x0F:
case 0x0C:
isNegative = false;
break;
default:
throw new Exception("Bad sign nibble");
}
long intermediate;
long carry;
long digit;
for (int j = inp.Length * 2 - 1; j > 0; j--)
{
// multiply by 10
intermediate = lo * 10;
lo = intermediate & 0xffffffff;
carry = intermediate >> 32;
intermediate = mid * 10 + carry;
mid = intermediate & 0xffffffff;
carry = intermediate >> 32;
intermediate = hi * 10 + carry;
hi = intermediate & 0xffffffff;
carry = intermediate >> 32;
// By limiting input length to 14, we ensure overflow will never occur
digit = nibble(inp, j);
if (digit > 9)
{
throw new Exception("Bad digit");
}
intermediate = lo + digit;
lo = intermediate & 0xffffffff;
carry = intermediate >> 32;
if (carry > 0)
{
intermediate = mid + carry;
mid = intermediate & 0xffffffff;
carry = intermediate >> 32;
if (carry > 0)
{
intermediate = hi + carry;
hi = intermediate & 0xffffffff;
carry = intermediate >> 32;
// carry should never be non-zero. Back up with validation
}
}
}
return new Decimal((int)lo, (int)mid, (int)hi, isNegative, (byte)scale);
}
private int nibble(byte[] inp, int nibbleNo)
{
int b = inp[inp.Length - 1 - nibbleNo / 2];
return (nibbleNo % 2 == 0) ? (b & 0x0000000F) : (b >> 4);
}
由于涉及到COMP-3值，您正在读取的文件格式几乎肯定具有固定记录大小和固定字段长度。如果我是您，我会在继续进行之前获取文件格式规范。您应该使用BinaryReader来处理此数据。如果有人对此提出反对意见，我会离开。让他们找别人来满足他们的愚蠢。
这是BASIC示例代码的VB.NET版本。由于我无法访问COMP-3文件，因此我尚未测试此代码。如果这不起作用，我会参考原始的MS示例代码以获得指导，或参考其他答案中关于此问题的参考资料。
Imports Microsoft.VisualBasic
Module Module1
'Sample COMP-3 conversion code
'Adapted from http://support.microsoft.com/kb/65323
'This code has not been tested
Sub Main()
Dim Digits%(15) 'Holds the digits for each number (max = 16).
Dim Basiceqv#(1000) 'Holds the Basic equivalent of each COMP-3 number.
'Added to make code compile
Dim MyByte As Char, HighPower%, HighNibble%
Dim LowNibble%, Digit%, E%, Decimal%, FileName$
'Clear the screen, get the filename and the amount of decimal places
'desired for each number, and open the file for sequential input:
FileName$ = InputBox("Enter the COBOL data file name: ")
Decimal% = InputBox("Enter the number of decimal places desired: ")
FileOpen(1, FileName$, OpenMode.Binary)
Do Until EOF(1) 'Loop until the end of the file is reached.
Input(1, MyByte)
If MyByte = Chr(0) Then 'Check if byte is 0 (ASC won't work on 0).
Digits%(HighPower%) = 0 'Make next two digits 0. Increment
Digits%(HighPower% + 1) = 0 'the high power to reflect the
HighPower% = HighPower% + 2 'number of digits in the number
'plus 1.
Else
HighNibble% = Asc(MyByte) \ 16 'Extract the high and low
LowNibble% = Asc(MyByte) And &HF 'nibbles from the byte. The
Digits%(HighPower%) = HighNibble% 'high nibble will always be a
'digit.
If LowNibble% <= 9 Then 'If low nibble is a
'digit, assign it and
Digits%(HighPower% + 1) = LowNibble% 'increment the high
HighPower% = HighPower% + 2 'power accordingly.
Else
HighPower% = HighPower% + 1 'Low nibble was not a digit but a
Digit% = 0 '+ or - signals end of number.
'Start at the highest power of 10 for the number and multiply
'each digit by the power of 10 place it occupies.
For Power% = (HighPower% - 1) To 0 Step -1
Basiceqv#(E%) = Basiceqv#(E%) + (Digits%(Digit%) * (10 ^ Power%))
Digit% = Digit% + 1
Next
'If the sign read was negative, make the number negative.
If LowNibble% = 13 Then
Basiceqv#(E%) = Basiceqv#(E%) - (2 * Basiceqv#(E%))
End If
'Give the number the desired amount of decimal places, print
'the number, increment E% to point to the next number to be
'converted, and reinitialize the highest power.
Basiceqv#(E%) = Basiceqv#(E%) / (10 ^ Decimal%)
Print(Basiceqv#(E%))
E% = E% + 1
HighPower% = 0
End If
End If
Loop
FileClose() 'Close the COBOL data file, and end.
End Sub
End Module
PIC 999v99 COMP-3 - Josh Stodola如果我偏离了主题，我很抱歉，但也许我在这里粘贴的代码示例可以帮助你。这段代码来自VBRocks...
Imports System
Imports System.IO
Imports System.Text
Imports System.Text.Encoding
'4/20/07 submission includes a line spacing addition when a control character is used:
' The line spacing is calculated off of the 3rd control character.
'
' Also includes the 4/18 modification of determining end of file.
'4/26/07 submission inclues an addition of 6 to the record length when the 4th control
' character is an 8. This is because these records were being truncated.
'Authored by Gary A. Lima, aka. VBRocks
''' <summary>
''' Translates an EBCDIC file to an ASCII file.
''' </summary>
''' <remarks></remarks>
Public Class EBCDIC_to_ASCII_Translator
#Region " Example"
Private Sub Example()
'Set your source file and destination file paths
Dim sSourcePath As String = "c:\Temp\MyEBCDICFile"
Dim sDestinationPath As String = "c:\Temp\TranslatedFile.txt"
Dim trans As New EBCDIC_to_ASCII_Translator()
'If your EBCDIC file uses Control records to determine the length of a record, then this to True
trans.UseControlRecord = True
'If the first record of your EBCDIC file is filler (junk), then set this to True
trans.IgnoreFirstRecord = True
'EBCDIC files are written in block lengths, set your block length (Example: 134, 900, Etc.)
trans.BlockLength = 900
'This method will actually translate your source file and output it to the specified destination file path
trans.TranslateFile(sSourcePath, sDestinationPath)
'Here is a alternate example:
'No Control record is used
'trans.UseControlRecord = False
'Translate the whole file, including the first record
'trans.IgnoreFirstRecord = False
'Set the block length
'trans.BlockLength = 134
'Translate...
'trans.TranslateFile(sSourcePath, sDestinationPath)
'*** Some additional methods that you can use are:
'Trim off leading characters from left side of string (position 0 to...)
'trans.LTrim = 15
'Translate 1 EBCDIC character to an ASCII character
'Dim strASCIIChar as String = trans.TranslateCharacter("S")
'Translate an EBCDIC character array to an ASCII string
'trans.TranslateCharacters(chrEBCDICArray)
'Translates an EBCDIC string to an ASCII string
'Dim strASCII As String = trans.TranslateString("EBCDIC String")
End Sub
#End Region 'Example
'Translate characters from EBCDIC to ASCII
Private ASCIIEncoding As Encoding = Encoding.ASCII
Private EBCDICEncoding As Encoding = Encoding.GetEncoding(37) 'EBCDIC
'Block Length: Can be fixed (Ex: 134).
Private miBlockLength As Integer = 0
Private mbUseControlRec As Boolean = True 'If set to False, will return exact block length
Private mbIgnoreFirstRecord As Boolean = True 'Will Ignore first record if set to true (First record may be filler)
Private miLTrim As Integer = 0
''' <summary>
''' Translates SourceFile from EBCDIC to ASCII. Writes output to file path specified by DestinationFile parameter.
''' Set the BlockLength Property to designate block size to read.
''' </summary>
''' <param name="SourceFile">Enter the path of the Source File.</param>
''' <param name="DestinationFile">Enter the path of the Destination File.</param>
''' <remarks></remarks>
Public Sub TranslateFile(ByVal SourceFile As String, ByVal DestinationFile As String)
Dim iRecordLength As Integer 'Stores length of a record, not including the length of the Control Record (if used)
Dim sRecord As String = "" 'Stores the actual record
Dim iLineSpace As Integer = 1 'LineSpace: 1 for Single Space, 2 for Double Space, 3 for Triple Space...
Dim iControlPosSix As Byte() 'Stores the 6th character of a Control Record (used to calculate record length)
Dim iControlRec As Byte() 'Stores the EBCDIC Control Record (First 6 characters of record)
Dim bEOR As Boolean 'End of Record Flag
Dim bBOF As Boolean = True 'Beginning of file
Dim iConsumedChars As Integer = 0 'Stores the number of consumed characters in the current block
Dim bIgnoreRecord As Boolean = mbIgnoreFirstRecord 'Ignores the first record if set.
Dim ControlArray(5) As Char 'Stores Control Record (first 6 bytes)
Dim chrArray As Char() 'Stores characters just after read from file
Dim sr As New StreamReader(SourceFile, EBCDICEncoding)
Dim sw As New StreamWriter(DestinationFile)
'Set the RecordLength to the RecordLength Property (below)
iRecordLength = miBlockLength
'Loop through entire file
Do Until sr.EndOfStream = True
'If using a Control Record, then check record for valid data.
If mbUseControlRec = True Then
'Read the Control Record (first 6 characters of the record)
sr.ReadBlock(ControlArray, 0, 6)
'Update the value of consumed (read) characters
iConsumedChars += ControlArray.Length
'Get the bytes of the Control Record Array
iControlRec = EBCDICEncoding.GetBytes(ControlArray)
'Set the line spacing (position 3 divided by 64)
' (64 decimal = Single Spacing; 128 decimal = Double Spacing)
iLineSpace = iControlRec(2) / 64
'Check the Control record for End of File
'If the Control record has a 8 or 10 in position 1, and a 1 in postion 2, then it is the end of the file
If (iControlRec(0) = 8 OrElse iControlRec(0) = 10) AndAlso _
iControlRec(1) = 1 Then
If bBOF = False Then
Exit Do
Else
'The Beginning of file flag is set to true by default, so when the first
' record is encountered, it is bypassed and the bBOF flag is set to False
bBOF = False
End If 'If bBOF = Fals
End If 'If (iControlRec(0) = 8 OrElse
'Set the default value for the End of Record flag to True
' If the Control Record has all zeros, then it's True, else False
bEOR = True
'If the Control record contains all zeros, bEOR will stay True, else it will be set to False
For i As Integer = 0 To 5
If iControlRec(i) > 0 Then
bEOR = False
Exit For
End If 'If iControlRec(i) > 0
Next 'For i As Integer = 0 To 5
If bEOR = False Then
'Convert EBCDIC character to ASCII
'Multiply the 6th byte by 6 to get record length
' Why multiply by 6? Because it works.
iControlPosSix = EBCDICEncoding.GetBytes(ControlArray(5))
'If the 4th position of the control record is an 8, then add 6
' to the record length to pick up remaining characters.
If iControlRec(3) = 8 Then
iRecordLength = CInt(iControlPosSix(0)) * 6 + 6
Else
iRecordLength = CInt(iControlPosSix(0)) * 6
End If
'Add the length of the record to the Consumed Characters counter
iConsumedChars += iRecordLength
Else
'If the Control Record had all zeros in it, then it is the end of the Block.
'Consume the remainder of the block so we can continue at the beginning of the next block.
ReDim chrArray(miBlockLength - iConsumedChars - 1)
'ReDim chrArray(iRecordLength - iConsumedChars - 1)
'Consume (read) the remaining characters in the block.
' We are not doing anything with them because they are not actual records.
'sr.ReadBlock(chrArray, 0, iRecordLength - iConsumedChars)
sr.ReadBlock(chrArray, 0, miBlockLength - iConsumedChars)
'Reset the Consumed Characters counter
iConsumedChars = 0
'Set the Record Length to 0 so it will not be processed below.
iRecordLength = 0
End If ' If bEOR = False
End If 'If mbUseControlRec = True
If iRecordLength > 0 Then
'Resize our array, dumping previous data. Because Arrays are Zero (0) based, subtract 1 from the Record length.
ReDim chrArray(iRecordLength - 1)
'Read the specfied record length, without the Control Record, because we already consumed (read) it.
sr.ReadBlock(chrArray, 0, iRecordLength)
'Copy Character Array to String Array, Converting in the process, then Join the Array to a string
sRecord = Join(Array.ConvertAll(chrArray, New Converter(Of Char, String)(AddressOf ChrToStr)), "")
'If the record length was 0, then the Join method may return Nothing
If IsNothing(sRecord) = False Then
If bIgnoreRecord = True Then
'Do nothing - bypass record
'Reset flag
bIgnoreRecord = False
Else
'Write the line out, LTrimming the specified number of characters.
If sRecord.Length >= miLTrim Then
sw.WriteLine(sRecord.Remove(0, miLTrim))
Else
sw.WriteLine(sRecord.Remove(0, sRecord.Length))
End If ' If sRecord.Length >= miLTrim
'Write out the number of blank lines specified by the 3rd control character.
For i As Integer = 1 To iLineSpace - 1
sw.WriteLine("")
Next 'For i As Integer = 1 To iLineSpace
End If 'If bIgnoreRecord = True
'Obviously, if we have read more characters from the file than the designated size of the block,
' then subtract the number of characters we have read into the next block from the block size.
If iConsumedChars > miBlockLength Then
'If iConsumedChars > iRecordLength Then
iConsumedChars = iConsumedChars - miBlockLength
'iConsumedChars = iConsumedChars - iRecordLength
End If
End If 'If IsNothing(sRecord) = False
End If 'If iRecordLength > 0
'Allow computer to process (works in a class module, not in a dll)
'Application.DoEvents()
Loop
'Destroy StreamReader (sr)
sr.Close()
sr.Dispose()
'Destroy StreamWriter (sw)
sw.Close()
sw.Dispose()
End Sub
''' <summary>
''' Translates 1 EBCDIC Character (Char) to an ASCII String
''' </summary>
''' <param name="chr"></param>
''' <returns></returns>
''' <remarks></remarks>
Private Function ChrToStr(ByVal chr As Char) As String
Dim sReturn As String = ""
'Convert character into byte
Dim EBCDICbyte As Byte() = EBCDICEncoding.GetBytes(chr)
'Convert EBCDIC byte to ASCII byte
Dim ASCIIByte As Byte() = Encoding.Convert(EBCDICEncoding, ASCIIEncoding, EBCDICbyte)
sReturn = Encoding.ASCII.GetString(ASCIIByte)
Return sReturn
End Function
''' <summary>
''' Translates an EBCDIC String to an ASCII String
''' </summary>
''' <param name="sStringToTranslate"></param>
''' <returns>String</returns>
''' <remarks></remarks>
Public Function TranslateString(ByVal sStringToTranslate As String) As String
Dim i As Integer = 0
Dim sReturn As New System.Text.StringBuilder()
'Loop through the string and translate each character
For i = 0 To sStringToTranslate.Length - 1
sReturn.Append(ChrToStr(sStringToTranslate.Substring(i, 1)))
Next
Return sReturn.ToString()
End Function
''' <summary>
''' Translates 1 EBCDIC Character (Char) to an ASCII String
''' </summary>
''' <param name="sCharacterToTranslate"></param>
''' <returns>String</returns>
''' <remarks></remarks>
Public Function TranslateCharacter(ByVal sCharacterToTranslate As Char) As String
Return ChrToStr(sCharacterToTranslate)
End Function
''' <summary>
''' Translates an EBCDIC Character (Char) Array to an ASCII String
''' </summary>
''' <param name="sCharacterArrayToTranslate"></param>
''' <returns>String</returns>
''' <remarks>Remarks</remarks>
Public Function TranslateCharacters(ByVal sCharacterArrayToTranslate As Char()) As String
Dim sReturn As String = ""
'Copy Character Array to String Array, Converting in the process, then Join the Array to a string
sReturn = Join(Array.ConvertAll(sCharacterArrayToTranslate, _
New Converter(Of Char, String)(AddressOf ChrToStr)), "")
Return sReturn
End Function
''' <summary>
''' Block Length must be set. You can set the BlockLength for specific block sizes (Ex: 134).
''' Set UseControlRecord = False for files with specific block sizes (Default is True)
''' </summary>
''' <value>0</value>
''' <returns>Integer</returns>
''' <remarks></remarks>
Public Property BlockLength() As Integer
Get
Return miBlockLength
End Get
Set(ByVal value As Integer)
miBlockLength = value
End Set
End Property
''' <summary>
''' Determines whether a ControlKey is used to calculate RecordLength of valid data
''' </summary>
''' <value>Default value is True</value>
''' <returns>Boolean</returns>
''' <remarks></remarks>
Public Property UseControlRecord() As Boolean
Get
Return mbUseControlRec
End Get
Set(ByVal value As Boolean)
mbUseControlRec = value
End Set
End Property
''' <summary>
''' Ignores first record if set (Default is True)
''' </summary>
''' <value>Default is True</value>
''' <returns>Boolean</returns>
''' <remarks></remarks>
Public Property IgnoreFirstRecord() As Boolean
Get
Return mbIgnoreFirstRecord
End Get
Set(ByVal value As Boolean)
mbIgnoreFirstRecord = value
End Set
End Property
''' <summary>
''' Trims the left side of every string the specfied number of characters. Default is 0.
''' </summary>
''' <value>Default is 0.</value>
''' <returns>Integer</returns>
''' <remarks></remarks>
Public Property LTrim() As Integer
Get
Return miLTrim
End Get
Set(ByVal value As Integer)
miLTrim = value
End Set
End Property
End Class
在EBCDIC或ASCII中，压缩字段是相同的。不要对它们运行EBCDIC到ASCII转换。在.Net中将它们转储到byte[]。
您可以使用位掩码和移位来打包/解包。 -- 但是，在.Net中，位运算仅适用于整数类型，因此您需要通过一些技巧来实现！
一个优秀的COBOL或C艺术家可以指引您正确的方向。
找到其中一位老手并付出您的代价（大约三杯啤酒就可以了）。
翻译表 - 用于检查压缩十进制字段中某些值的实用工具： http://www.simotime.com/asc2ebc1.htm
msdn 中代码页的列表： http://msdn.microsoft.com/en-us/library/dd317756(VS.85).aspx
以及一个用于在 C# 中转换字节数组字段的代码：
// 500 is the code page for IBM EBCDIC International
System.Text.Encoding enc = new System.Text.Encoding(500);
string value = enc.GetString(byteArrayField);
“ASCII传输类型”会将文件作为常规文本文件传输。因此，在ASCII传输类型下传输压缩的十进制或二进制数据文件时，文件容易损坏。 “二进制传输类型”会以二进制模式传输数据，将文件处理为二进制数据而不是文本数据。因此，我们必须在这里使用二进制传输类型。 参考：https://www.codeproject.com/Tips/673240/EBCDIC-to-ASCII-Converter
一旦您的文件准备好，这里有一个将压缩的十进制转换为可读十进制的代码。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp2
{
class Program
{
static void Main(string[] args)
{
var path = @"C:\FileName.BIN.dat";
var templates = new List<Template>
{
new Template{StartPos=1,CharLength=4,Type="AlphaNum"},
new Template{StartPos=5,CharLength=1,Type="AlphaNum"},
new Template{StartPos=6,CharLength=8,Type="AlphaNum"},
new Template{StartPos=14,CharLength=1,Type="AlphaNum"},
new Template{StartPos=46,CharLength=4,Type="Packed",DecimalPlace=2},
new Template{StartPos=54,CharLength=5,Type="Packed",DecimalPlace=0},
new Template{StartPos=60,CharLength=4,Type="Packed",DecimalPlace=2},
new Template{StartPos=64,CharLength=1,Type="AlphaNum"}
};
var allBytes = File.ReadAllBytes(path);
for (int i = 0; i < allBytes.Length; i += 66)
{
var IsLastline = (allBytes.Length - i) < 66;
var lineLength = IsLastline ? 64 : 66;
byte[] lineBytes = new byte[lineLength];
Array.Copy(allBytes, i, lineBytes, 0, lineLength);
var outArray = new string[templates.Count];
int index = 0;
foreach (var temp in templates)
{
byte[] amoutBytes = new byte[temp.CharLength];
Array.Copy(lineBytes, temp.StartPos - 1, amoutBytes, 0,
temp.CharLength);
var final = "";
if (temp.Type == "Packed")
{
final = Unpack(amoutBytes, temp.DecimalPlace).ToString();
}
else
{
final = ConvertEbcdicString(amoutBytes);
}
outArray[index] = final;
index++;
}
Console.WriteLine(string.Join(" ", outArray));
}
Console.ReadLine();
}
private static string ConvertEbcdicString(byte[] ebcdicBytes)
{
if (ebcdicBytes.All(p => p == 0x00 || p == 0xFF))
{
//Every byte is either 0x00 or 0xFF (fillers)
return string.Empty;
}
Encoding ebcdicEnc = Encoding.GetEncoding("IBM037");
string result = ebcdicEnc.GetString(ebcdicBytes); // convert EBCDIC Bytes ->
Unicode string
return result;
}
private static Decimal Unpack(byte[] inp, int scale)
{
long lo = 0;
long mid = 0;
long hi = 0;
bool isNegative;
// this nybble stores only the sign, not a digit.
// "C" hex is positive, "D" hex is negative, AlphaNumd "F" hex is unsigned.
var ff = nibble(inp, 0);
switch (ff)
{
case 0x0D:
isNegative = true;
break;
case 0x0F:
case 0x0C:
isNegative = false;
break;
default:
throw new Exception("Bad sign nibble");
}
long intermediate;
long carry;
long digit;
for (int j = inp.Length * 2 - 1; j > 0; j--)
{
// multiply by 10
intermediate = lo * 10;
lo = intermediate & 0xffffffff;
carry = intermediate >> 32;
intermediate = mid * 10 + carry;
mid = intermediate & 0xffffffff;
carry = intermediate >> 32;
intermediate = hi * 10 + carry;
hi = intermediate & 0xffffffff;
carry = intermediate >> 32;
// By limiting input length to 14, we ensure overflow will never occur
digit = nibble(inp, j);
if (digit > 9)
{
throw new Exception("Bad digit");
}
intermediate = lo + digit;
lo = intermediate & 0xffffffff;
carry = intermediate >> 32;
if (carry > 0)
{
intermediate = mid + carry;
mid = intermediate & 0xffffffff;
carry = intermediate >> 32;
if (carry > 0)
{
intermediate = hi + carry;
hi = intermediate & 0xffffffff;
carry = intermediate >> 32;
// carry should never be non-zero. Back up with validation
}
}
}
return new Decimal((int)lo, (int)mid, (int)hi, isNegative, (byte)scale);
}
private static int nibble(byte[] inp, int nibbleNo)
{
int b = inp[inp.Length - 1 - nibbleNo / 2];
return (nibbleNo % 2 == 0) ? (b & 0x0000000F) : (b >> 4);
}
class Template
{
public string Name { get; set; }
public string Type { get; set; }
public int StartPos { get; set; }
public int CharLength { get; set; }
public int DecimalPlace { get; set; }
}
}
}
文件必须以二进制方式传输。以下是更简短的方法：
using System.Linq;
namespace SomeNamespace
{
public static class SomeExtensionClass
{
/// <summary>
/// computes the actual decimal value from an IBM "Packed Decimal" 9(x)v9 (COBOL) format
/// </summary>
/// <param name="value">byte[]</param>
/// <param name="precision">byte; decimal places, default 2</param>
/// <returns>decimal</returns>
public static decimal FromPackedDecimal(this byte[] value, byte precision = 2)
{
if (value.Length < 1)
{
throw new System.InvalidOperationException("Cannot unpack empty bytes.");
}
double power = System.Math.Pow(10, precision);
if (power > long.MaxValue)
{
throw new System.InvalidOperationException(
$"Precision too large for valid calculation: {precision}");
}
string hex = System.BitConverter.ToString(value).Replace("-", "");
var bytes = Enumerable.Range(0, hex.Length)
.Select(x => System.Convert.ToByte($"0{hex.Substring(x, 1)}", 16))
.ToList();
long place = 1;
decimal ret = 0;
for (int i = bytes.Count - 2; i > -1; i--)
{
ret += (bytes[i] * place);
place *= 10;
}
ret /= (long)power;
return (bytes.Last() & (1 << 7)) != 0 ? ret * -1 : ret;
}
}
}