witespaces cause command to fail, when in backquotes

dannyboy34 · 09-02-2016, 06:04 PM

How to work with files|dirs with spaces> I'vs tried the following command below but it fails:

> ls -ald `find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"`

I am familiar with the -exec ls option of the find utility.
The goal rather of this post is to understand why the command fails when directories with spaces are found.
By my reasoning, the backquoted `...` output should have all find results encapsulated with quotes so all should be fine,
Example:

> find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"
> "./dir1/dir2/dir3 with spaces"
> "./dir4/dir5/dir6 with spaces"
>
> ls -ald `find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"`
> ls: cannot access "./dir1/dir2/dir3: No such file or directory
> ls: cannot access with: No such file or directory
> ls: cannot access spaces": No such file or directory
> ls: cannot access "./dir4/dir5/dir6: No such file or directory
> ls: cannot access with: No such file or directory
> ls: cannot access spaces": No such file or directory

BTW:
> ls -ald `find . -type d -name "* *" ! -wholename "*.svn*" -print0`
fails also

Thanks
Danny

keefaz · 09-02-2016, 06:16 PM

Use quotes

Code:

ls -ald "`find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"`"

But there are surely other simple ways to achieve what you want to do

grail · 09-02-2016, 07:03 PM

Quotes will not work in this case as all the directories found will be joined as one single item, which of course does not exist.

If this has to be done, I would suggest using the -exec option or xargs

rknichols · 09-02-2016, 07:06 PM

Quote:

Originally Posted by dannyboy34

> ls -ald `find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"`

By my reasoning, the backquoted `...` output should have all find results encapsulated with quotes so all should be fine,

None of those quote marks are escaped, so they are all being processed by the shell prior to execution of find. If you use "set -x" first, you will see what is actually being passed

Code:

set -x
find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"
+ find . -type d '!' -wholename '*.svn*' -name '* *' -printf '%p\n'
./dir1/dir2/dir3 with spaces
./dir4/dir5/dir6 with spaces

Escaping those literal quotes only looks like it should work

Code:

find . -type d ! -wholename "*.svn*" -name "* *" -printf "\"%p\"\n"
+ find . -type d '!' -wholename '*.svn*' -name '* *' -printf '"%p"\n'
"./dir1/dir2/dir3 with spaces"
"./dir4/dir5/dir6 with spaces"

The problem there with command substitution is that the quoting for the outer command line has already been done, so those returned quotes are (a) not going to affect word splitting, and (b) are going to get passed literally to the ls command:

Code:

ls -ald `find . -type d ! -wholename "*.svn*" -name "* *" -printf "\"%p\"\n"`
++ find . -type d '!' -wholename '*.svn*' -name '* *' -printf '"%p"\n'
+ ls --color=auto -ald '"./dir1/dir2/dir3' with 'spaces"' '"./dir4/dir5/dir6' with 'spaces"'
ls: cannot access "./dir1/dir2/dir3: No such file or directory
ls: cannot access with: No such file or directory
ls: cannot access spaces": No such file or directory
ls: cannot access "./dir4/dir5/dir6: No such file or directory
ls: cannot access with: No such file or directory
ls: cannot access spaces": No such file or directory

The closest (I didn't say "best". As you are aware, using "-exec" would be better.) reasonably clean way to do that is to use a NUL separator and "xargs -0":

Code:

find . -type d ! -wholename "*.svn*" -name "* *" -printf "%p\0" | xargs -0 ls -ald

Quote:

Originally Posted by keefaz

Use quotes

Code:

ls -ald "`find . -type d ! -wholename "*.svn*" -name "* *" -printf ""%p"\n"`"

That's just going to pass the entire list (including the internal newlines) as a single, quoted argument to ls, which would work fine if exactly one directory is found. Fails otherwise.

chrism01 · 09-03-2016, 03:56 AM

You might find the -print0 option to the 'find' cmd useful:
http://linux.die.net/man/1/find
https://superuser.com/questions/1186...rgs-and-print0

Shadow_7 · 09-03-2016, 02:24 PM

The shell interpreter likely strips of the ""'s before interpretation. So using -- can help overcome that or doing escape-age or at least escape the middle space *\ *, or "(backslash)"* *(backslash)"" type tricks. Mostly the -- thing, or using $() instead of `` sometimes helps, although mostly for nested commands.

forum strips some of the \'s.