To delete a file who's file name is a pain to define (eg. ^H^H^H) find it's inode number with the command "ls -il". Use the line below to find and delete the file.

find . -inum 12345 | xargs rm

To find out the number of files of each type in your current directory try the following:

find ${*-.} -type f | xargs file | awk -F, '{print $1}' | awk '{$1=NULL;print $0}' | sort | uniq -c | sort -nr  

   5  PHP script text
   2  data
   2  Zip archive data
   2  GIF image data
   1  PNG image data

(You may want to add this as an alias rather than type it in each time!)

Add the following alias and function to your profile to be able to copy and paste files at the command line:

ccopy(){ cp $1 /tmp/ccopy.$1; }
alias cpaste="ls /tmp/ccopy* | sed 's|[^\.]*.\.||' | xargs -I % mv /tmp/ccopy.% ./%"

You can see below how this can be used:

blackbird:~/tst tks1$ ls
1.txt   2.txt   t1.tss  t2.tss  t3.tss
blackbird:~/tst tks1$ ccopy 1.txt
blackbird:~/tst tks1$ ccopy 2.txt


blackbird:~/tst tks1$ cd ../tst2
blackbird:~/tst2 tks1$ ls


blackbird:~/tst2 tks1$ cpaste


blackbird:~/tst2 tks1$ ls
1.txt   2.txt

To remove empty directories (even if filenames or dirnames contain spaces or weird characters) from a tree you can do:

find . -type d -empty -print0 | xargs -0 rmdir

Make a backup of existing files, afterwards copy new files from somedir:

1. Go to proddir

ls /update-200805/ |xargs -n1 -I xxx cp xxx xxx.`date +%Y%m%d` ; cp /update-200805/* . 

The following command creates in the /usr/project directory, a copy of the current working directory structure:

find . -type d -print|sed 's@^\.\{0,1\}@/usr/project@' | sed 's/ /\\ /' | xargs mkdir -p

And again about file extension changing.

There are two tips about this:
#27 - http://www.shell-fu.org/lister.php?id=27
#544 - http://www.shell-fu.org/lister.php?id=544

I'm happy to provide one more variant. It's up to you which one is the most useful.

function chext(){
  local fname
  local new_ext="$1"
  shift
  IFS=$'\n'
  for fname in $@
  do
    mv "$fname" "${fname%.*}.$new_ext"
  done
}

If you place this function into .bashrc, then you may use it like as follows:

chext new_ext *.old_ext
chext html `find ~ -iname "*.htm"`
find ~ -iname "*.htm" | xargs chext html

Kick all users other than you from your box and keep them out.

watch -d 'w | awk 'NR==4 {print "/dev/"$2}' | xargs fuser -k'

This is the general form; it will run 'mycommand' once for each line of text you enter with that line of text supplying the arguments to the command:

cat | xargs -L1 mycommand

Changing to ledit adds readline support:

ledit | xargs -L1 mycommand

Example: A simple REPL for sending commands to a DBus object:

ledit | xargs -L1 -ILINE dbus-send --print-reply --dest=mydest myobj myiface.LINE

ls | xargs rm

Sometime there are so many files in a directory than the rm command doesn't work

[root@server logs]# rm *
bash: /bin/rm: Argument list too long

On this case the best option is to use ls in conjuntion with xargs

[root@server logs]# ls | xargs rm

It's for removing those orphaned config files! :D

aptitude search ~c | awk '{ print $2 }' | xargs aptitude -y purge