Ubuntu – Copy files and directories without files content

In these situations there is a risk of files with the same name being overwritten. As mentioned by @Arronical, you can avoid this using the -b flag to mv which causes any identically named files to be differentiated by appending ~ to their names. However, if there are three or more files with the same name, only the first and last will be saved, so check the contents before moving to protect your files.

The first, simple case is easy; we can use a shell glob. However, this won't move hidden files, so if you have any filenames beginning with ., start by turning on dotglob

shopt -s dotglob

Then you can run:

mv -b /home/smit/test/* /home/smit
rmdir /home/smit/test

Turn off dotglob if you like (it will return to default anyway when you open a new shell):

shopt -u dotglob

For the second (real) case, we will use find, which moves hidden files by default:

Make sure you are in the right location first.

cd /usr/share/background/all
find -type f -exec echo mv -vb -- {} . \;

If that looks good, run it without echo to actually move files

find -type f -exec mv -vb -- {} . \;

Then find the directories

find -type d

If you see what you want to remove:

find -type d -delete

This is safe since it will refuse to remove directories that still have contents.

I haven't examined the output with symlinks but:

find . -type f -iname '*.c' -printf '%h\0' |
  sort -z |
  uniq -zc |
  sed -zr 's/([0-9]) .*/\1 1/' |
  tr '\0' '\n' |
  awk '{f += $1; d += $2} END {print f, d}'

• The find command prints the directory name of each .c file it finds.
• sort | uniq -c will gives us how many files are in each directory (the sort might be unnecessary here, not sure)
• with sed, I replace the directory name with 1, thus eliminating all possible weird characters, with just the count and 1 remaining
• enabling me to convert to newline-separated output with tr
• which I then sum up with awk, to get the total number of files and the number of directories that contained those files. Note that d here is essentially the same as NR. I could have omitted inserting 1 in the sed command, and just printed NR here, but I think this is slightly clearer.

Up until the tr, the data is NUL-delimited, safe against all valid filenames.

With zsh and bash, you can use printf %q to get a quoted string, which would not have newlines in it. So, you might be able to do something like:

shopt -s globstar dotglob nocaseglob
printf "%q\n" **/*.c | awk -F/ '{NF--; f++} !c[$0]++{d++} END {print f, d}'

However, even though ** is not supposed to expand for symlinks to directories, I could not get the desired output on bash 4.4.18(1) (Ubuntu 16.04).

$ shopt -s globstar dotglob nocaseglob
$ printf "%q\n" ./**/*.c | awk -F/ '{NF--; f++} !c[$0]++{d++} END {print f, d}'
34 15
$ echo $BASH_VERSION
4.4.18(1)-release

But zsh worked fine, and the command can be simplified:

$ printf "%q\n" ./**/*.c(D.:h) | awk '!c[$0]++ {d++} END {print NR, d}'
29 7

D enables this glob to select dot files, . selects regular files (so, not symlinks), and :h prints only the directory path and not the filename (like find's %h) (See sections on Filename Generation and Modifiers). So with the awk command we just need to count the number of unique directories appearing, and the number of lines is the file count.