"find | xargs | ls" not running ls on filenames from find-CodePudding

So I have a directory with files and sub-directories in it. I want to get all the files recursively and then list them in long format, sorted by the modified date. Here's what I came up with.

find . -type f | xargs -d "\n" | ls -lt

However this only lists the files in the current directory and not the sub-directories. I don't understand why, given that the following prints out all the files.

find . -type f | xargs -d "\n" | cat

Any help appreciated.

CodePudding user response：

xargs can only start ls if it's passed ls as an argument. When you pipe from xargs into ls, only one copy of ls is started -- by the parent shell -- and it isn't given any of the filenames from find | xargs as arguments -- instead they're on its stdin, but ls never reads its stdin, so it doesn't even know that they're there.

Thus, you need to remove the | character:

# Does what you specified in the common case, but buggy; don't use this
# (filenames can contain newlines!)
# ...also, xargs -d is GNU-only
find . -type f | xargs -d '\n' ls -lt

...or, better:

# uses NUL separators, which cannot exist inside filenames
# also, while a non-POSIX extension, this is supported in both GNU and BSD xargs
find . -type f -print0 | xargs -0 ls -lt

...or, even better than that:

# no need for xargs at all here; find -exec can do the same thing
# -exec ... {}   is POSIX-mandated functionality since 2008
find . -type f -exec ls -lt {}

Much of the content in this answer is also covered in the Actions, Complex Actions, and Actions in Bulk sections of Using Find, which is well worth reading.