BASE64DEC

BASE64DEC 2080 enhanced 

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Action

Converts Base-64 data into the original data.

 

 

Syntax

Result = BASE64DEC( source)

array = BASE64DEC( source, elements)

 

 

Remarks

Result

A string variable that is assigned with the un-coded string.

Source

The source string that is coded with base-64.

array

A byte array that is assigned with the un-coded strings

elements

The number of elements in the resulting array

 

Base-64 is not an encryption protocol. It sends data in 7-bit ASCII data format. MIME, web servers, and other Internet servers and clients use Base-64 coding.

 

The provided Base64Dec() function is a decoding function. It was written to add authentication to the web server sample.

When the web server asks for authentication, the client will send the user and password unencrypted, but base-64 coded to the web server.

Base-64 coded strings are always in pairs of 4 bytes. These 4 bytes represent 3 bytes.

 

Because strings can not contain a 0 byte, there is an alternative syntax. Instead of a string you assign a byte array.

The byte variable ELEMENTS is assigned with the number of elements filled with data.

 

 

 

See also

CONFIG TCPIP, GETSOCKET , SOCKETCONNECT, SOCKETSTAT , TCPWRITE, TCPWRITESTR, CLOSESOCKET , SOCKETLISTEN , BASE64ENC , URL2IP

 

 

Example

$regfile = "m48def.dat"                                   ' specify the used micro

$crystal = 8000000                                         ' used crystal frequency

$baud = 19200                                               ' use baud rate

$hwstack = 32                                               ' default use 32 for the hardware stack

$swstack = 10                                               ' default use 10 for the SW stack

$framesize = 40                                             ' default use 40 for the frame space

$lib "tcpip.lbx"

Config Com1 = Dummy , Synchrone = 0 , Parity = None , Stopbits = 1 , Databits = 8 , Clockpol = 0

 

 

Dim S As String * 15 , Z As String * 15

 

S = "bWFyazptYXJr"

Z = Base64dec(s)

Print Z                                                     'mark:mark

End

 

 

Example 2

$regfile = "m32U4def.dat"
$crystal = 16000000
$baud = 19200
 
Dim S As String * 80 , Z As String * 80 , B As Byte , J As Byte
Dim Ar(81) As Byte At S Overlay
 
S = "This is a test"
'while we load the array with string data, we could load it with any data that can contain a 0.
 
B = Len(s) + 1                                             'get the length and the 0 byte
Z = Base64enc(ar(1) , B)                                   'use an array
Print Z
 
Ar(1) = Base64dec(z , B)                                   'now B will hold the number of elements
 
Print B
 
'Another example
Ar(1) = 0 : Ar(2) = 1 : Ar(3) = 2
Z = Base64enc(ar(1) , 3)                                   'use an array
Print Z
 
 
Ar(1) = Base64dec(z , B)                                   'now B will hold the number of elements
For J = 1 To B
  Print Ar(j)
Next
End