Need help with batch file

[jacdelad]

Hello,
I have a batch file with the following content:

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echo startplib >> I:\st1.dat

According to what I know this should only print out "startplib >> I:\st1.dat" on the screeen. However, ">>" seems to be some kind of pipe (I had expected "|") and the output data of "startlib" is saved into "I:\st1.dat".

My questions are:
Why does this not just simply print out the rest of the line after "echo"?
What does ">>" exactly do?

[normeus]

you found the append to the end pipe >>

escape the special characters:

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echo startplib ^>^> d:\st1.dat

or just enclose text in quotes

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echo "startplib >> d:\st1.dat"

Norm.

[jacdelad]

Ah ok. So if st1.dat already exists the new data will just be appended, while | always starts a new file?

[Marc56us]

This is shell commands (aka "DOS" commands) and unix/linux shell

> : create new file or overwrite if exist
echo Hello > txt.txt
echo Hello > txt.txt
type txt.txt

>> : append to file if exist or create new
echo Hello > txt.txt
echo World >> txt.txt
type txt.txt

| : Tee
Help cmd | more
Help cmd | findstr ">"

[jacdelad]

Ah great, thanks very much!

Now, I still don't understand why the "echo"-command is needed. Can you explain that too?

[akee]

echo is like print in basic.

so print "hello" to the file txt.txt.

> is like createfile() command.
>> is like openfile() command with #PB_File_Append.