`os.symlink` vs `ln -s`

bash, linux, python, symlink

Solution

`os.symlink` creates a single symlink.

`ln -s` creates multiple symlinks (if its last argument is a directory, and there's more than one source). The Python equivalent is something like:

dst = args[-1]
for src in args[:-1]:
    os.symlink(src, os.path.join(dst, os.path.dirname(src)))

So, how does it work when you do `ln -s /home/guest/dir1/* /home/guest/dir2/`? Your shell makes that work, by turning the wildcard into multiple arguments. If you were to just `exec` the `ln` command with a wildcard, it would look for a single source literally named `*` in `/home/guest/dir1/`, not all files in that directory.

The Python equivalent is something like (if you don't mind mixing two levels together and ignoring a lot of other cases—tildes, env variables, command substitution, etc. that are possible at the shell):

dst = args[-1]
for srcglob in args[:-1]:
    for src in glob.glob(srcglob):
        os.symlink(src, os.path.join(dst, os.path.dirname(src)))

You can't do that with `os.symlink` alone—either part of it—because it doesn't do that. It's like saying "I want to do the equivalent of `find . -name foo` using `os.walk` without filtering on the name." Or, for that matter, I want to do the equivalent of `ln -s /home/guest/dir1/* /home/guest/dir2/` without the shell globbing for me."

The right answer is to use `glob`, or `fnmatch`, or `os.listdir` plus a regex, or whatever you prefer.

Do not use `os.walk`, because that does a recursive filesystem walk, so it's not even close to shell `*` expansion.

Problem

I need to create a symlink for every item of dir1 (file or directory) inside `dir2`. `dir2` already exists and is not a symlink. In Bash I can easily achieve this by: ``` ln -s /home/guest/dir1/* /home/guest/dir2/ ``` But in python using `os.symlink` I get an error: ``` >>> os.symlink('/home/guest/dir1/*', '/home/guest/dir2/') Traceback (most recent call last): File "<stdin>", line 1, in <module> OSError: [Errno 17] File exist ``` I know I can use `subprocess` and run `ln` command. I don't want that solution. I'm also aware that workarounds using `os.walk` or `glob.glob` are possible, but I want to know if it is possible to do this using `os.symlink`.

Original source