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How to tell if a file exists in Perl

藏色散人
藏色散人Original
2019-02-15 13:39:252609browse

Perl has a useful set of file test operators that can be used to see if a file exists. There is -e in it, which checks if the file exists. This information may be useful to you when you are working with a script that requires access to a specific file, and you want to ensure that the file exists before performing an operation.

How to tell if a file exists in Perl

For example, if your script has a dependent log or configuration file, check it first. The example script below raises a descriptive error if the file is not found using this test.

#!/usr/bin/perl
$filename = '/path/to/your/file.doc';
if (-e $filename) {
print "File Exists!";
}

First, create a string containing the path to the file you want to test. Then wrap the -e(exists) statement in a conditional block so that the print statement (or whatever you put there) is only called if the file exists. You can test the opposite - file does not exist - by using an unless condition:

unless (-e $filename) {
print "File Doesn't Exist!";
}

Other File Test Operators

You can use "and" (&&) or "or" (|| ) operator tests two or more things at once. Some other Perl file testing operators are:

Check if the file is readable

w Check if the file is writable

-x Check if the file is executable

-zCheck whether the file is empty

fCheck whether the file is a normal file

-dCheck whether the file is a directory

lCheck whether the file is a symbolic link

Using file testing can help you avoid errors or make you aware of errors that need to be fixed.

Related recommendations: "Perl Tutorial"http://www.php.cn/course/list/39.html

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