perl function truncate

The truncate function in Perl is used to truncate a file to a specified length or to truncate a string. The syntax of the truncate function is as follows:

truncate FILEHANDLE, LENGTH
truncate EXPR, LENGTH

Here, FILEHANDLE is the file handle of the file to be truncated, and LENGTH is the new length of the file. EXPR can be any expression that returns a file handle.

If LENGTH is greater than the current file size, the file is extended with null bytes. If LENGTH is less than the current file size, the file is truncated to the specified length.

If EXPR is used instead of FILEHANDLE, the truncate function truncates the string represented by EXPR to the specified length.

Here is an example of using the truncate function to truncate a file to a specified length:

open(FILE, ">>file.txt") || die "Cannot open file: $!";
print FILE "This is some text\n";
truncate(FILE, 15);
close(FILE);

In this example, the open function is used to open the file "file.txt" in append mode. The print function is used to write some text to the file. Then, the truncate function is used to truncate the file to a length of 15 bytes. Finally, the close function is used to close the file. After running this code, the file "file.txt" will contain the text "This is some te".