[SOLVED] LN -s question

scasey · 11-01-2019, 02:57 AM

So the file name is literally "Name of File - Screenshot (1).jpg"?
then

Code:

for file in $(ls . |grep jpg); do ln -s "$file" "/volume1/Screenshots/Screenshots Firefox dd 01-11/$file"  ; done

should work.

iammike2 · 11-01-2019, 03:05 AM

Quote:

Originally Posted by scasey

So the file name is literally "Name of File - Screenshot (1).jpg"?
then

Code:

for file in $(ls . |grep jpg); do ln -s "$file" "/volume1/Screenshots/Screenshots Firefox dd 01-11/$file"  ; done

should work.

Yep that are the file names.

Thx, will try it, and report back

Edit-1: Nope it doesn't work. Same error.

scasey · 11-01-2019, 03:11 AM

OK. I'll check tomorrow...it's 0100 here now.

I guess I'm doubting that every filename starts with "Name of File".
Are you at the command line in a terminal?
On a web page? In some graphical application?

iammike2 · 11-01-2019, 03:32 AM

Quote:

Originally Posted by scasey

OK. I'll check tomorrow...it's 0100 here now.

I guess I'm doubting that every filename starts with "Name of File".
Are you at the command line in a terminal?
On a web page? In some graphical application?

Via Putty / thus command line

I am not sure why you are doubting what the structure of the filenames is

Name of File, can be indeed something else, but the structure is this

<part 1> Name of file -> Can be different can be 2 chars long can be 20 chars long (and thus can have spaces)

<part 2> - Screenshot -> Always the same
<part 3> (1).jpg -> incremental and if an error occurred there is "!" added so like this (!1).jpg

BUT before you say anything I am testing it in a dir with only 7 files at the moment and what are they called ????? Indeed

Name of File - Screenshot (1).jpg etc etc etc etc etc

Why I choose "Name of File", because it has everything the other files have, Caps, Lower Case, Space thus if this one works all the other ones will as well.

Happy now or still NOT convinced ????

Thx for all the help, but leave it, I am fed up with it, I am going to do it manually !! Spend too much time on it already if I had done it manually I would be half way right now

iammike2 · 11-01-2019, 03:49 AM

The plot thickens

doing this now

src dir = /volume1/test (NO spaces)
dest dir = /volume1/test/1 (no spaces)
file name = a.jpg (no spaces)

and this what happens

Code:

sh-4.3# pwd
/volume1/test
sh-4.3# for file in $(ls . |grep jpg); do ln -s $file "/volume1/test/1/$file"  ; done
ln: failed to create symbolic link ‘/volume1/test/1/a.jpg’: File exists

After running this, In the 1 dir a file exists !a.jpg

scasey · 11-01-2019, 02:23 PM

Quote:

Originally Posted by iammike2

Yep that are the file names.

Thx, will try it, and report back

Edit-1: Nope it doesn't work. Same error.

What error?
Again...please note quotes.

Code:

for file in $(ls . |grep jpg); do ln -s "$file" "/volume1/Screenshots/Screenshots Firefox dd 01-11/$file"  ; done

iammike2 · 11-01-2019, 07:06 PM

Same error as in post #20.

ln: failed to create symbolic link ‘/volume1/test/1/a.jpg’: File exists

And there was NO file in /1/ BEFORE I ran this. After running there was a file in /1/ which was called (looked in MC) !a.jpg. A normal SL file would look like @a.jpg.

I am now starting to think it's something quirky with the OS (Synology DSM)

iammike2 · 11-01-2019, 08:28 PM

Another try

Without quotes

Code:

sh-4.3# for file in $(ls . |grep jpg); do ln -s $file /volume1/test/1/$file  ; done
sh-4.3# mc

Result: NO Error but also NO File found in /1/

with quotes

Code:

sh-4.3# for file in $(ls . |grep jpg); do ln -s "$file" "/volume1/test/1/$file"  ; done
sh-4.3# pwd
/volume1/test
sh-4.3# mc

Result: No Error but a file created in /1/ with filename !a.jpg (note the ! in front)

And changing LS for Find

Code:

sh-4.3# for file in $(find . -maxdepth 1 -name "*.jpg"); do ln -s "$file" "/volume1/test/1/$file"  ; done
sh-4.3# mc

Result: No Error but a file created in /1/ with filename !a.jpg (note the ! in front)

Running out of ideas here

iammike2 · 11-01-2019, 08:34 PM

This one works

Code:

sh-4.3# for file in $(find . -maxdepth 1 -name "*.jpg"); do ln -s /volume1/test/$file /volume1/test/1/$file  ; done
sh-4.3# mc

Result: File created in /1/ with as name @a.jpg

Oke another try created "This is a test.jpg", so there are 2 files 1) a.jpg and 2) "This is a test.jpg"

Code:

sh-4.3# for file in $(find . -maxdepth 1 -name "*.jpg"); do ln -s "/volume1/test/$file" "/volume1/test/1/$file"  ; done
sh-4.3# mc

Result in /1/ there is a @a.jpg and also the following files
!This
!a
!is
!test.jpg

This is what it looks like

Code:

drwxrwxrwx+ 2 root root  4096 Nov  2 08:42 .
drwxrwxrwx+ 7 root root  4096 Nov  2 08:35 ..
lrwxrwxrwx  1 root root   19 Nov  2 08:42 a -> /volume1/test/a
lrwxrwxrwx  1 root root   25 Nov  2 08:42 a.jpg -> /volume1/test/./a.jpg
lrwxrwxrwx  1 root root   20 Nov  2 08:42 is -> /volume1/test/is
lrwxrwxrwx  1 root root   26 Nov  2 08:42 test.jpg -> /volume1/test/test.jpg
lrwxrwxrwx  1 root root   24 Nov  2 08:42 This -> /volume1/test/./This

iammike2 · 11-01-2019, 08:49 PM

I am getting my new Raspberry 4 this week and will try it on that one, if it works on that one it has something to do with the OS on my NAS.

Thx for the help thus far.

scasey · 11-01-2019, 09:04 PM

I’m not familiar with mc.
Maybe the ! identifies a link?

Yes, something strange is happening. ln shouldn’t create a link to a file that doesn’t exist.

iammike2 · 11-01-2019, 09:09 PM

! = (AFAIK) a failed Symlink
@ = (AFAIK) a correct Symlink

Will report back after I have received my Raspb4 and have tested it

Thanks again for the help, appreciated.

tofino_surfer · 11-02-2019, 11:49 AM

It is quite messy to use ls with grep for this. The find utility is much more professional and can do everything in a single command. Using -maxdepth 1 limits the results to the directory specified just as ls without -R for recursion would do.

Code:

find "source path with spaces" -maxdepth 1 -type f -name '*.jpg' | while read file; 
do 
   ln -s "<source path with spaces>"/$file "<destination path with spaces>"/$file;
done

An alternate form with process substitution and input redirection is:

Code:

while read file; 
do 
   ln -s "<source path with spaces>"/$file "<destination path with spaces>"/$file;
done < <(find "source path with spaces" -maxdepth 1 -type f -name '*.jpg')

crts · 11-02-2019, 03:00 PM

Quote:

Originally Posted by tofino_surfer

It is quite messy to use ls with grep for this. The find utility is much more professional and can do everything in a single command. Using -maxdepth 1 limits the results to the directory specified just as ls without -R for recursion would do.

Code:

find "source path with spaces" -maxdepth 1 -type f -name '*.jpg' | while read file; 
do 
   ln -s "<source path with spaces>"/$file "<destination path with spaces>"/$file;
done

Alternately in the form from previous messages without a while loop

Code:

for file in $(find "source path with spaces" -maxdepth 1 -type f -name '*.jpg'); 
do 
   ln -s "<source path with spaces>"/$file "<destination path with spaces>"/$file;
done

The while loop works well but the for loop will split the found files on every space. If you want to use a for I recommend using wildcards:

Code:

for file in "source path with spaces"/*.jpg; do
    ln -s "$(realpath -e "$file")" "path to target directory"
done

Keep in mind, that a symlink must point to the target as seen from its own location, i.e., it must either be an absolute path or a relative path wich is relative from the link's location.
Hence, I recommend to additionally resolve to an absolute path with realpath. If you know the single, absolute location beforehand, as in OP's case, you can use the absolute path just as well. Personally, I prefer to resolve with realpath. It can handle multiple path locations.

PS:
If files in deeper directories are to be processed then the while loop in combination with find should be preferred.

crts · 11-02-2019, 04:31 PM

Quote:

Originally Posted by scasey

Yes, something strange is happening. ln shouldn’t create a link to a file that doesn’t exist.

ln will throw an error if you try to create a hardlink to a non-existant file. However, it will create broken symbolic links:

Code:

$ ln -s non-existant-file symlink
$ echo $?
0

It will even exit with SUCCESS code.