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why does help for copy mention /B so much in parameters?

Posted: 06 Oct 2024 01:11
by taripo
why does help for copy mention /B so much in parameters?

Let's say I create a file , with an 1A(EOF) character in there. I can view it with the more command.

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C:\Users\User>echo 616263 | xxd -r -p >c:\crp\a.a

C:\Users\User>type c:\crp\a.a
abc
C:\Users\User>echo 6162631A646566 | xxd -r -p >c:\crp\a.a

C:\Users\User>type c:\crp\a.a
abc
C:\Users\User>more c:\crp\a.a
abc→def
So the file is

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C:\Users\User>xxd c:\crp\a.a
00000000: 6162 631a 6465 66                        abc.def
If I combine it with itself to make a new file g.g

C:\Users\User>copy /Y /B c:\crp\a.a + c:\crp\a.a g.g
c:\crp\a.a
c:\crp\a.a
1 file(s) copied.

C:\Users\User>

Then that works

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C:\Users\User>more g.g
abc→defabc→def

C:\Users\User>xxd g.g
00000000: 6162 631a 6465 6661 6263 1a64 6566       abc.defabc.def

C:\Users\User>
So why is it that the COPY /? documentation makes it look like you have to include /B lots of times

Like before all source files. And then after each source file and after the destination file

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COPY [/D] [/V] [/N] [/Y | /-Y] [/Z] [/L] [/A | /B ] source [/A | /B]
     [+ source [/A | /B] [+ ...]] [destination [/A | /B]]
It seems to me that it only needs to be put in once. That is, before all source files.

Re: why does help for copy mention /B so much in parameters?

Posted: 06 Oct 2024 05:05
by aGerman
Options at the beginning apply to all sources and the destination. However, you can also define it for every source separately as well as for the destination. In this case you better really define /a or /b for every file as such options are seemingly taken over for the rest of the command if you leave them out.

Steffen

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Microsoft Windows [Version 10.0.22631.4249]
(c) Microsoft Corporation. Alle Rechte vorbehalten.

C:\Users\steffen\Desktop>more a.a
abc␦def

C:\Users\steffen\Desktop>copy /y /b a.a + a.a g.g
a.a
a.a
        1 Datei(en) kopiert.

C:\Users\steffen\Desktop>more g.g
abc␦defabc␦def

C:\Users\steffen\Desktop>copy /y a.a + a.a /b g.g
a.a
a.a
        1 Datei(en) kopiert.

C:\Users\steffen\Desktop>more g.g
abcabc␦def

C:\Users\steffen\Desktop>copy /y a.a /b + a.a g.g
a.a
a.a
        1 Datei(en) kopiert.

C:\Users\steffen\Desktop>more g.g
abc␦defabc␦def

C:\Users\steffen\Desktop>copy /y a.a /b + a.a /a g.g
a.a
a.a
        1 Datei(en) kopiert.

C:\Users\steffen\Desktop>more g.g
abc␦defabc␦

C:\Users\steffen\Desktop>copy /y a.a /b + a.a /a g.g /b
a.a
a.a
        1 Datei(en) kopiert.

C:\Users\steffen\Desktop>more g.g
abc␦defabc

C:\Users\steffen\Desktop>