BashBites:How to Append Outputs to a File

Is there any way to append output(debugging information) to a existings file? As we all know in bash the command ‘>’ will write ouputs to a file.However this command will also erase the existing data it the file.
Of course bash provides a command that appends outputs to a file.It resembles ‘>’.It’s ‘>>’
The following is a piece of example code.

Let’s look at >

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[[email protected] tmp]$ touch a.txt
[[email protected] tmp]$ cat a.txt
[[email protected] tmp]$ echo "ABC"[[email protected] tmp]$ cat a.txt
ABC
[[email protected] tmp]$ echo "DEF"[[email protected] tmp]$ cat a.txt
DEF

Well,Let’s look at the exiciting command >>

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[[email protected] tmp]$ echo "GHI"[[email protected] tmp]$ cat a.txt
DEF
GHI