#ref https://www.baeldung.com/linux/xargs

Q: why me
A: convert STDIN into parmeters, since rm canNOT take stdin

ls | rm --> FAIL
ls | xargs rm --> ok since xargs get stdin and convert it to rm parameters

#3.1. Limit Output per Line
ls | xargs
ls | xargs -n 1

#3.3. Insert Arguments at a Particular Position
-- use I can insert argument into any position
ls | xargs -I {} echo rclone copy {} koofr:foo/ 	# -I {} --> then you can use parameter with command at any location 

#4. Handling Files with Special Characters in the Names
$ ls -l
total 1789
-rw-r--r--  1 cpfong  wheel  910679 May 20 10:41 mini-screenshots 2024-05-20 上午10.38.07.png
-rw-r--r--  1 cpfong  wheel  894860 May 20 10:41 mini-screenshots 2024-05-20 上午10.38.09.png

ls *.png | xargs -I % echo rclone copy % koofr:foo/		#FAIL!
ls *.png | xargs -I % echo rclone copy \"%\" koofr:foo/		#ok

#To deal with this problem, both xargs and the command passing the output to xargs must use a null character as the record separator.
# fileName contain ' or "
find . -name 'file*' | rm #FAIL
find . -name 'file*' -print0 | rm -0 rm 			# change xargs use null char as separator


$ xargs
a b
c
^D (done with input)

now xargs have 3 parameters: a b and c
default cmd (if not input) is /bin/echo

echo a b c

it can take the 1st arg as cmd
$ xargs cat file1
file2
^D
it will cat file1 and cat file2



find . -name "*.bak" -type f -print | xargs echo /bin/rm -f
$ find . -name "*.c" -type f | sh ~/tmp/trash/test.sh | head -n1
rm './foo.c'

$ cat test.sh
#!/bin/sh

cat "$@" |
while IFS= read -r line
do
 printf "rm \'$line\'\n"	# file name can have space (ex 'file nmae.c'
done
$