Perl Study notes--File test

The file test is used primarily to view information such as the existence of a file, file size, file update time, and so on.

File Test Operators

Whether the-e test file exists;

Die "oops! A file called ' $filename ' already exists.\n "if-e $filename;

-m test files maintain continuous updates, such as testing whether a program's log files remain updated every week or two weeks.

The file handle is tested here.

Warn "Config file is looking pretty old!\n" if-m config>28;

-s the size of the test file, in bytes to calculate the file size.

Example: The following test is a file that is larger than 100 bytes in size and the update date is less than two days under this folder.

#!/usr/bin/env Perl
#filename: test2.pl Use 5.010; while(<>){    if(/\a-.*/){        my @line=Split/\s+/,"$&";#say "$line [8]";Say"$line [8]\tis bigger than 100bytes."        if-S$line[8] > -And-m$line[8] >2; }}
Run command: ls-l | ./<filename>

How to view the size of a file in M: My size= (-s $filename)/1024;

Be sure to add parentheses.

Other file test items

-r: File or directory for this (valid) User (effective User) or group is readable-w: file or directory on this (valid) user or group is writable by-x: File or directory on this (valid) user or group is executable-o: File or directory owned by this (valid) user All-r: file or directory to this user (real user) Or a group is readable-W: A file or directory to which this user or group is writable-x: A file or directory to which this user or group is executable-o: File or directory owned by this user-e: File or directory name exists-Z: file exists, size is 0 (directory constant is False)-S: File or directory exists, Size greater than 0 (value is file size, Unit: bytes)-F: For plain text-D: For directory-L: For Symbolic Link-s: for Socket-p pipe (Entry is a named pipe (a "FIFO"))-B: For block-special Files (such as mounted disks)-C: Files or directories-g:setgid files or directories-u:setuid for character-special files (such as I/O devices)-k:file or directory has the sticky bit set-t: The handle is the return result of the TTY (System function isatty (); Cannot use this test for file names)-T: Files are somewhat like "text" Files-B: Files are somewhat like "binary" FILE-M: Modified time (in days)-A: The time of Access (in days)-C: Index node Modification time (units: Days)

test multiple properties of the same file

if (-R $file and-w _) # Virtual file Handle _

{... }

Stack file Operators

Use 5.010;

if (-r-w-x-o-D $file) {

Print "My directory is Readable,writable,and executable!\n";

}

Perl Study notes--File test