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From: svirsky@ttidca.TTI.COM (Bill Svirsky)
Newsgroups: comp.sys.ibm.pc
Subject: Re: append " >> " is not working, why? (LONG)
Message-ID: <6230@ttidca.TTI.COM>
Date: 19 Sep 89 02:16:40 GMT
References: <4734@shlump.nac.dec.com> <2553@pur-phy>
Reply-To: svirsky@ttidcc.tti.com (Bill Svirsky)
Organization: Citicorp/TTI, Santa Monica
Lines: 114

In article <2553@pur-phy> qz@maxwell.physics.purdue.edu.UUCP (Qin Zhao) writes:
+  Hi, I recently got some problem when I tried to concatenate two files.
+What I have done is following:
+  There is tow file: file1 and file2 ( I got from somebody else ).
+  I gave command:
+		 type file2 >> file1
+ in order to put file2 at the end of file1.  And then I used "dir" to check 
+the size of file1, it was increased by the  size of file2.
+However, when I tried to read the contents of file1, I could only see the 
+original part of file1. I had used several editors, and "type" commands. 
+But when I rewrote  file1 using the editor, the size of file1 drops to the 
+original size of file1.

As has been previously mentioned, your editor is stopping at the
imbedded ^Z (EOF) character. Now about concatenating files:

The following is true for Compaq DOS 3.31 and IBM DOS 3.10. I believe it
holds true for any DOS 3+. I'm not sure about DOS 2.

The copy command in DOS makes for interesting reading. It can be used
in many ways. A word of warning up front though; be *very* careful when
copying files and using wildcards. You can stomp on your files.

To simply concatenate text "file2" to text "file1", you can use

1)	copy file1+file2

To concatenate text "file1" and text "file2" and put the results into a new
file, "file3", you can use

2)	copy file1+file2 file3

If you don't specify a destination file, DOS appends to the 1st file in
the list. Thus, the example 1 can be extended to many more files.

3)	copy file1+file2+file3+...

In fact, you can use wildcards, such as

4)	copy file1+file*

to concatenate all files that start with "file" and have no extension
to "file1". Unfortunately, DOS doesn't guarantee ascending sequence when
it expands wildcards, it expands wildcards in the order that they show
up in the directory. So, if a DIR displays the files in the following
order:

	file3
	file1
	file2

the example 4 would have the same results as if you entered

5)	copy file1+file3+file2

Well, not *exactly* the same results. Example 4 will generate 1 or more
warning messages like

	Content of destination lost before copy

What really happens is that DOS expands the command into something like

6)	copy file1+file3+file1+file2

Now DOS tries not to copy a file onto itself. But it doesn't compare an
input filename to the destination filename until it is ready to copy
it. So, when it gets to the 2nd "file1", it then checks to make sure
that the destination filename is not "file1". It not only sees that the
destination file is "file1", but it thinks that the original contents of
"file1" have been trashed. So it warns you. In this case DOS is wrong
but, lets say you have files

	my.lst
	your.lst
	our.lst

all of which are near and dear to you. You normally create "our.lst" by
using

7)	copy *.lst our.lst

but in this case, you've spent hundred's of hours editing "our.lst" and
just want to concatenate "my.lst" and "your.lst" to it. However, when
you enter the command, your fingers betray you and  enter the familiar
command above. As you realize what you did, you think "No need to worry,
MS-DOS won't copy a file onto itself. I'm safe". WROOOONG! DOS copies
"my.lst" and "your.lst" onto "our.lst" before it gets to "our.lst" and
checks to see if it is overwriting a file. It is already too late,
"our.lst" is trashed, so DOS warns you. Crushed by your loss, you swear
off MS-DOS (after swearing at MS-DOS), sell your PC and buy a Mac (-:.
The moral of the story is; be careful using wildcards with copy.

To get serious once again: You can also use wildcards with
concatenation. For instance

8)	copy *.h+*.c allsrc

will concatenate all of your ".h" files and all of your ".c" files and
place the results into "allsrc".

A couple of final notes: the "/A" (ASCII) option and "/B" (BINARY)
options apply only to the file immediately preceding the option and to
all subsequent files until the next "/A" or "/B". "/A" is the default
for concatenation, "/B" for normal copying.

I hope this has all been lucid enough. It's getting late and things are
getting fuzzy. I have not covered all of the COPY command, just some of
the high points. You'll have to read the rest yourself.


-- 
Bill Svirsky, Citicorp+TTI, 3100 Ocean Park Blvd., Santa Monica, CA 90405
Work phone: 213-450-9111 x2597
svirsky@ttidca.tti.com | ...!{csun,psivax,rdlvax,retix}!ttidca!svirsky