[Reprinted] the base64 codec program written by Niu Ren in batch

Awesome!

It is estimated that there should be few bugs. Who can optimize it?

 

: Base64.cmd beta -- base64 encoding and decoding 01/28/2007 by 0401
@ Echo off
Setlocal enabledelayedexpansion
Set op =
Set key = abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789 +/=
Set hexstr = 0 1 2 3 4 5 6 7 8 9 A B C D E F
Set D = 0
For % I in (% hexstr %) do set D! D! = % I & set/A D + = 1
If "% ~ 1 "=" "Goto: Help
If "% ~ 1 "= "/? "Goto: Help
For % I In (d e h) Do (
If "% ~ 1 "="/% I "Call: Arg % I % *
If exist "% ~ 1 "(
If exist "% ~ 1/"set error = sorry. base64 encoding is not supported for a directory. & Goto: Error
Set op = encode
Set infile = % ~ Sf1
)
)
If defined error Goto: Error
If defined op Goto: % OP %
Set error = Invalid parameter or file name: % 1. & Goto: Error

: Arge
Set op = encode
: Argd
If not defined OP set op = decode
Set infile = % ~ Sf2
If not defined infile set error = the input file is not specified. & Exit/B
If not exist "% infile %" set error = the specified file cannot be found: % infile %. & Exit/B
Set OUTFILE = % ~ F3
Goto: EOF
: Argh
Set op = Help
Goto: EOF
: Error
Echo % error %
Exit/B

Goto: encode
S file size
L add the 100 h f sub-command to the file to fill in the memory length.
C is only used to calculate the first encoding time.
K judge C1 C2 C3
W each line generates several 4-byte encoding characters. The default value is 18.
If Q is equal to W, a line of encoded strings is output.
N is used to filter out duplicate bytes.
: Encode
> NUL (chcp 437 & graftabl 936)
CLS
For % I in (% infile %) do set S = % ~ Zi
If % S % equ 0 exit/B
If % S % gtr 65535 set error = encoding failed. The maximum file size is 64 KB. & Goto: Error
Set/P = encoding initializing. Please wait. <NUL
Set of = b64enc
Set/P = <NUL> "% ~ Dp0 % of %"
Set/a l = S + 255
Call: D2H % L %
Set L = % hex %
Call: D2H % S %
Echo exit | % comspec %/kprompt F Cs: 100 l % L % 0a $ _ r CX $ _ % hex % $ _ n. t1 $ _ w $ _ f Cs: 100 l % L % 0d $ _ n B. t1 $ _ w $ _ q $ _ | debug> NUL
FC/B % infile % A. T1 | find ":">. T1
FC/B % infile % B. T1 | find ":">. T1
Sort. T1>. T2
Call: time t1
Set n =
Set C = 0
Set K = 0
Set q = 0
Set W = 18
For/F "tokens = 1, 2" % I in (. T2) Do (
If not "! N! "=" % I "(
Set/a d = 0x % J
Set/a k + = 1
If! K! Equ 1 Set C1 =! D!
If! K! Equ 2 set C2 =! D!
If! K! Equ 3 set C3 =! D!
If! K! Equ 3 (
Set/A e1 = "C1> 2!
Set/A e2 = "(C1 & 3) <4) | (c2> 4 )"
Set/A E3 = "(C2 & 15) <2) | (C3> 6 )"
Set/A E4 = "C3 & 63"
Call set b64 =! B64! % Key :~! E1 !, 1% % key :~! E2 !, 1% % key :~! E3 !, 1% % key :~! E4 !, 1% %
Set/a q + = 1
If! Q! Equ! W! (
Echo! B64!> "% ~ Dp0 % of %"
Set b64 =
Set q = 0
If! C! Equ 0 (
Set/a C + = 1
Call: time t2
Set/a t = "s/(w * 3) * (t2-t1)/100"
Echo estimated remaining time! T! Seconds.
)
Set/P = # <NUL
)
Set K = 0
)
)
Set n = % I
)
If! K! Equ 1 (
Set/A e1 = "C1> 2"
Set/A e2 = "(C1 & 3) <4"
Call set b64 =! B64! % Key :~! E1 !, 1% % key :~! E2 !, 1% % =
)
If! K! Equ 2 (
Set/A e1 = "C1> 2"
Set/A e2 = "(C1 & 3) <4) | (c2> 4 )"
Set/A E3 = "(C2 & 15) <2 )"
Call set b64 =! B64! % Key :~! E1 !, 1% % key :~! E2 !, 1% % key :~! E3 !, 1% % =
)
Echo.
If defined b64 echo % b64 %> "% ~ Dp0 % of %"
If defined OUTFILE move/y "% ~ Dp0 % of % "" % OUTFILE %"
Echo encoding is complete.
Del A. t1 B. T1. T1. T2
: Chcp 936> NUL
Exit/B

Goto: Decode
K is used to determine E1 E2 E3 E4
The number of bytes written in each line by the E sub-command. The default value is 24 bytes to generate a debug e sub-command. Can be modified by yourself (3 <= e <= 24)
Hex string after S1 Conversion
M determines whether S1 contains the specified number of bytes.
Q each row has (several bytes * 3) encoded
CX indicates the file size (in bytes). Each operation adds 3 because each 4 bytes is decoded into 3 bytes.
How many offsets does the CS e subcommand write in the CS segment address?
V1 adds 2 bytes to each row (two bytes both press enter and line feed)
V2 rows
3 times of V3 Q to determine the time used to process 1st rows
: Decode
> NUL (chcp 437 & graftabl 936)
CLS
Set/P = decoding <NUL
Set/P = <NUL> dbg. SRC
Set/P V1 = <% infile %
Set/P = % V1 % <NUL>. T1
For % I in (. T1) do set/A Q = % ~ Zi/4 & set V1 = % ~ Zi + 2 & del. T1
For % I in (% infile %) do set/A v2 = % ~ Zi/V1 + 1
Set/A V3 = "Q * 3"
Call: time t1
Set E = 24
Set k = 1
Set M = 1
Set Cx = 0
Set cs = 256
For/F % I in (% infile %) Do (
Set STR = % I
For/L % J in (1, 1, % Q %) Do (
If not defined STR if % j lss % Q % Goto: decend
For/L % K in (0, 1, 3) Do (
For/L % L in (0, 1, 64) Do (
If "! STR :~ % K, 1! "= "! Key :~ % L, 1! "(
If! K! Equ 1 set E1 = % L
If! K! Equ 2 set E2 = % L
If! K! Equ 3 set E3 = % L
If! K! Equ 4 set E4 = % L
Set/a k + = 1
)
)
)
Set/A C1 = "(E1 <2) | (E2> 4 )"
Call: D2H! C1!
Set S1 =! S1! ! Hex!
Set/a C2 = "(E2 & 15) <4) | (E3> 2 )"
Call: D2H! C2!
Set S1 =! S1! ! Hex!
Set/A C3 = "(E3 & 3) <6) | E4"
Call: D2H! C3!
Set S1 =! S1! ! Hex!

Set k = 1
Set/A cx + = 3
Set/a m = Cx "%" E
If! M! Equ 0 (
If! E4! Equ 64 (
Set/a cx-= 1
Set S1 =! S1 :~ 0,-3!
If! E3! Equ 64 (
Set/a cx-= 1
Set S1 =! S1 :~ 0,-3!
)
)
Call: D2H! CS!
Echo e! Hex! ! S1! > Dbg. SRC
Set/a Cs + = E
Set S1 =
)
Set STR =! STR :~ 4!
)
If! CX! Equ % V3 % (
Call: time t2
Set/a TS = t2-t1
Set/a t = "TS * vv2/100"
Echo, total files! V2! Line. It takes about every line! TS! Millisecond, estimated remaining time! T! Seconds.
)
Set/P = # <NUL
)
: Decend
If defined S1 (
If % E4 % equ 64 (
Set/a cx-= 1
Set S1 =! S1 :~ 0,-3!
If % E3 % equ 64 (
Set/a cx-= 1
Set S1 =! S1 :~ 0,-3!
)
)
Call: D2H % CS %
Echo e! Hex! ! S1! > Dbg. SRC
)
Call: D2H % CX %
(Echo R CX
Echo % hex %
Echo n b64dec
Echo W
Echo q)> dbg. SRC
Echo.
Debug <dbg. SRC> NUL
If defined OUTFILE move/y b64dec "% OUTFILE %"
Echo decoding is completed.
Del dbg. SRC
: Chcp 936> NUL
Exit/B

: Time
For/F "tokens = 1-4 delims =:." % I in ("% time %") Do (
Set/A time1 = "% I * 360000"
Set/A time2 = "(1% % j-100) * 6000"
Set/A time3 = "(1% % K-100) * 100"
Set/A time4 = "1% % L-100"
)
Set/A % ~ 1 = time1 + time2 + time3 + time4
Exit/B
: D2H
Set/a d = % 1
Set hex =
If % d % equ 0 set hex = 00 & Exit/B
If % d % gtr 255 (set C = 4) else (set C = 2)
For/L % I in (1, 1, % C %) Do (
Set/a td = D "&" 15
Set/a d ">>=" 4
Call set hex = % d! TD! %! Hex!
)
Exit/B

: Help
For/F "tokens = 1 delims =:" % I in ('findstr/n/C: "= help =" "% ~ F0 "') do more + % I" % ~ F0 "> Con & Goto: EOF
Base64 encode N decode beta by 0401
Usage:
Base64 [/E] filename1 [filename2]
[/D filename1] [filename2]
[/H]
/E base64 encoding operation, processing file size limit 64kb
/D base64 Decoding
Filename1 input file name
Filename2 output file name
/E the default output file name is b64enc.
/D the default output file name is b64dec.
/H help