Perl Language Primer--3--file read and write

The existing file Test.txt, the content is: "123\n456"

1, Open Text test.txt

#!/usr/bin/perl

Open D, "test.txt";

D is the file handle, pointing to the open file

2, read text line by row Test.txt

#!/usr/bin/perl

Open D, "< test.txt";

while (<d>) {

Print $_;

}

Close D;

Results: 123

456

Or: Print <d>;

Results: Ibid.

<> is the fetch operator.

3, write content to Test111.txt

#!/usr/bin/perl

Open D, ">test111.txt";

Print F "Hello,world\nsee you\n";

Close D;

If Test111.txt original content, then the original content will be erased, the content of Test111.txt is

Hello,world

See you

4, append content to Test111.txt

#!/usr/bin/perl

Open D, ">>test111.txt";

Print d "Thank you\n";

Close D;

The content of Test111.txt is

Hello,world

See you

Thank

Print is equivalent to writing a command, do not lose the end of the statement ";"

Perl Language Primer--3--file read and write