Perl-Python-a-Day: split a file full path

[Xah Lee]

Split File Fullpath Into Parts

Xah Lee, 20051016

Often, we are given a file fullpath and we need to split it into the
directory name and file name. The file name is often split into a core
part and a extension part. For example:

'/Users/t/web/perl-python/I_Love_You.html'
becomes

'/Users/t/web/perl-python/' (directory name)
'I_Love_You' (file's base name)
'.html' (file's “extensionâ€)


Depending on the language, some language will remove the trailing slash
after the dir name, and some will omit the dot before the suffix.

In Python, to split a full path into parts is done with the os.path
module. Example:

# python
import os.path

myPath = '/Users/t/web/perl-python/I_Love_You.html'
(dirName, fileName) = os.path.split(myPath)
(fileBaseName, fileExtension)=os.path.splitext(fileName)

print dirName # /Users/t/web/perl-python
print fileName # I_Love_You.html
print fileBaseName # I_Love_You
print fileExtension # .html


The official doc of the os.path module is at:
http://www.python.org/doc/2.4.1/lib/module-os.path.html

In Perl, spliting a full path into parts is done like this:

# perl
use File::Basename;

$myPath = '/Users/t/web/perl-python/I_Love_You.html';

($fileBaseName, $dirName, $fileExtension) = fileparse($myPath,
('\.html') );

print $fileBaseName, "\n"; # I_Love_You
print $dirName, "\n"; # /Users/t/web/perl-python/
print $fileExtension, "\n"; # .html


Note: the second argument to fileparse() is a list of regex. In
particular, you need to escape the dot.

For the official doc, type in command line: “perldoc File:athâ€.
------
This post is archived at
http://xahlee.org/perl-python/split_fullpath.html

Schemers, a scsh version will be appreciated.

Xah
(e-mail address removed)
∑ http://xahlee.org/

 

[Dr.Ruud]

Xah Lee:

In Perl, spliting a full path into parts is done like this:

And then follows Perl-code that only works with an optional .html
"extension",
which is similar to the code in the File::Basename description.
http://www.perl.com/doc/manual/html/lib/File/Basename.html


It is best practice to derive and store the normalized (or absolute)
path, because relative paths can get loose so will get loose.


Consider this:

$myPath = './example/basename.ext';


and this:

$myPath = './example/filename.1.23.45-beta';


and this:

$myPath = 'x:.\example\basename.ext';


(some platforms have a wd per device)

 

[matteo d'addio 81]

Hello, I'm a cs student from Milano (Italy).
I don't use scsh fequently but this should work:

(open srfi-11 ;let-values
srfi-28) ;format

(define my-path "/Users/t/web/perl-python/I_Love_You.html")

(let-values (((dir-name
file-base-name
file-extension) (parse-file-name my-path)))

(format "~a~%" dir-name) ;/Users/t/web/perl-python/
(format "~a~%" file-base-name) ;I_Love_You
(format "~a~%" file-extension)) ;.html

You can find more useful function here (scsh reference manual):
http://www.scsh.net/docu/html/man-Z-H-6.html#node_sec_5.1

matteo

 

[Xah Lee]

And then follows Perl-code that only works with an optional .html
"extension",

Thanks for the note. I've corrected it here:
http://xahlee.org/perl-python/split_fullpath.html

namely:
Note: the second argument to fileparse() is a list of regex. In
particular, you need to escape the dot. Normally, one gives it a value
such as ('\.html', '\.HTML', '\.jpg', '\.JPG'). Yes, it is case
sensitive. If you want to match any extension (that is, the string
after the last dot), use ('\.[^.]+$').

Xah
(e-mail address removed)
∑ http://xahlee.org/