Perl has several functions to operate on functions the opendir(), readdir() and closedir() functions are a common way to achieve this.
opendir(DIR_HANDLE,"directory") returns a Directory handle -- just an identifier (no $) -- for a given directory to be opened for reading.
Note that exact or subpath directories may be required.
BE WARNED: Macintosh directory paths are denoted by : in this instance UNIX
directory paths are denoted by /
.
readdir(DIR_HANDLE) returns a scalar (string) of the basename of the file (no sub
directories (: or /
))
closedir(DIR_HANDLE) simply closes the directory.
Therefore to list all files a given directory we can do the following readdir.pl:
opendir(DIR,"Maclab:Internet") || die "NO SUCH Directory: Images"; while ($file = readdir(DIR) ) { print " $file\n"; } closedir(DIR);
The above reads a folder Internet on the top level of the Maclab hard disk.
On UNIX we may do:
opendir(DIR,"./Internet") || die "NO SUCH Directory: Images"; while ($file = readdir(DIR) ) { print " $file\n"; } closedir(DIR);
The above reads a sub-directory Internet assumed to be located in the same directory from where the Perl script has been run.
One further example to alphabetically list files is alpha.pl:
opendir(DIR,"./Internet") || die "NO SUCH Directory: Images"; foreach $file ( sort readdir(DIR) ) { print " $file\n"; } closedir(DIR);