What is the basic syntax of the zip_read() function? What are its parameters and specific usage?

In PHP, zip_read() is a function used to read entries within a ZIP archive. It is typically used in conjunction with zip_open(), which allows developers to traverse various file or directory entries within the ZIP file, enabling operations and processing on the compressed package.

1. Basic Syntax of the zip_read() Function

resource zip_read(resource $zip);

• Parameter Description:

  • $zip: The ZIP resource handle returned by zip_open().

• Return Value:

  • Returns a resource handle pointing to a ZIP entry on success.

  • Returns false on failure.

2. Parameter Details

zip_read() has only one parameter, which is the ZIP resource handle. This handle is obtained after opening a ZIP file using the zip_open() function.

For example:

$zip = zip_open('http://m66.net/path/to/your.zip');
if (is_resource($zip)) {
    while ($entry = zip_read($zip)) {
        // Process $entry
    }
    zip_close($zip);
}

3. Specific Usage

Typically, we use zip_read() in combination with other functions to read files within a ZIP file. For example:

• zip_entry_name() retrieves the name of the current entry.

• zip_entry_filesize() retrieves the size of the current entry.

• zip_entry_open() opens the current entry to read its contents.

• zip_entry_read() reads the content of the entry.

• zip_entry_close() closes the current entry.

Example code is as follows:

$zip = zip_open('http://m66.net/files/example.zip');
if (is_resource($zip)) {
    while ($entry = zip_read($zip)) {
        $name = zip_entry_name($entry);
        echo "File Name: $name\n";
        $size = zip_entry_filesize($entry);
        $contents = zip_entry_read($entry, $size);
        echo "File Contents:\n$contents\n";
        zip_entry_close($entry);
    }
}
zip_close($zip);

} else {
echo "Unable to open ZIP file";
}

In this example:

1. The ZIP file located at http://m66.net/files/example.zip is opened using zip_open().

2. All entries are looped through using zip_read().

3. Entry names are output using zip_entry_name().

4. The contents of entries are read using zip_entry_open() and zip_entry_read().

5. Entries and ZIP resources are closed.

4. Important Notes

• zip_read() depends on zip_open(), so the ZIP file resource must be successfully opened first.

• To read remote ZIP files, the PHP directive allow_url_fopen must be enabled.

• This function is suitable for sequential reading of a ZIP file, but not for random access of entries.

• If you only need to list file names, skip reading the content to avoid performance overhead.