Perl 简明教程

Perl - Directories

下面是用于处理目录的标准函数。

opendir DIRHANDLE, EXPR  # To open a directory
readdir DIRHANDLE        # To read a directory
rewinddir DIRHANDLE      # Positioning pointer to the begining
telldir DIRHANDLE        # Returns current position of the dir
seekdir DIRHANDLE, POS   # Pointing pointer to POS inside dir
closedir DIRHANDLE       # Closing a directory.

Display all the Files

有各种方法可以列出特定目录中所有可用的文件。首先，我们使用简单的方法，即使用 glob 运算符获取并列出所有文件 −

#!/usr/bin/perl

# Display all the files in /tmp directory.
$dir = "/tmp/*";
my @files = glob( $dir );

foreach (@files ) {
   print $_ . "\n";
}

# Display all the C source files in /tmp directory.
$dir = "/tmp/*.c";
@files = glob( $dir );

foreach (@files ) {
   print $_ . "\n";
}

# Display all the hidden files.
$dir = "/tmp/.*";
@files = glob( $dir );
foreach (@files ) {
   print $_ . "\n";
}

# Display all the files from /tmp and /home directories.
$dir = "/tmp/* /home/*";
@files = glob( $dir );

foreach (@files ) {
   print $_ . "\n";
}

这里有另一个示例，它打开了一个目录，并列出此目录中所有可用的文件。

#!/usr/bin/perl

opendir (DIR, '.') or die "Couldn't open directory, $!";
while ($file = readdir DIR) {
   print "$file\n";
}
closedir DIR;

可以用来打印 C 源文件列表的另一个示例是 −

#!/usr/bin/perl

opendir(DIR, '.') or die "Couldn't open directory, $!";
foreach (sort grep(/^.*\.c$/,readdir(DIR))) {
   print "$_\n";
}
closedir DIR;

Create new Directory

您可以使用 mkdir 函数创建一个新目录。您需要具有创建目录的必需权限。

#!/usr/bin/perl

$dir = "/tmp/perl";

# This creates perl directory in /tmp directory.
mkdir( $dir ) or die "Couldn't create $dir directory, $!";
print "Directory created successfully\n";

Remove a directory

您可以使用 rmdir 函数删除一个目录。您需要具有删除目录的必需权限。此外，尝试删除它之前，此目录应该是空的。

#!/usr/bin/perl

$dir = "/tmp/perl";

# This removes perl directory from /tmp directory.
rmdir( $dir ) or die "Couldn't remove $dir directory, $!";
print "Directory removed successfully\n";

Change a Directory

您可以使用 chdir 函数更改一个目录并前往一个新位置。您需要具有更改目录和进入新目录的必需权限。

#!/usr/bin/perl

$dir = "/home";

# This changes perl directory  and moves you inside /home directory.
chdir( $dir ) or die "Couldn't go inside $dir directory, $!";
print "Your new location is $dir\n";