Read and write into file perl

Sobrique Sobrique Ah Thanks alot for the help! What surprises me a bit is that you didn't get any errors. I would have thought the print statement would error. It's trying to call a subroutine called 'FILE2' which doesn't exist. Can I please ask what is the difference between looping over a file handle with while or using foreach? It will therefore trigger reading the whole file in advance, put it in an array and iterate that array.

A while loop reads one line at a time. So the foreach is at best redundant, and at worst wastes memory. Unless you actually need to hold the file content in memory.

See: stackoverflow. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. See also: Reading a file into a variable opens new window. Another and faster way to read a file is to use File::Slurper Module. This is useful if you work with many files. See also: [Reading a file with slurp] opens new window. This code opens a file for writing. Returns an error if the file couldn't be opened.

Also closes the file at the end. Next we can direct output to that file using the print operator:. Since it is defined in the open operator it is treated as a filehandle. The last parameter is the path of the file to write the data to. To write the data into the file, the print operator is used along with the filehandle.

Notice that in the print operator there is no comma between the filehandle and the statement itself, just whitespace. Since Perl 5. When used, Perl will automatically check for errors when opening and closing files. We will give you several examples of writing to files. Before going forward with this tutorial, you need to know how to open a file in Perl. If you want to read from a file, follow the reading from a file tutorial. In order to write to a file, first you need to open the file for writing as follows:.

Notice that if you write to a file that contains content, Perl will truncate its content.