However, as pointed out by manatwork, as detailed in the xargs man page:
-I replace-str
Replace occurrences of replace-str in the initial-arguments with
names read from standard input. Also, unquoted blanks do not
terminate input items; instead the separator is the newline
character. Implies -x and -L 1.
The important thing to note is that -L 1 means that only one line of output from find will be processed at a time. This means that's syntactically the same as:
find /tmp/ -ctime -1 -name "x*" -exec mv '{}' ~/play/
(which executes a single mv operation for each file).
Even using the GNU -0 xargs argument and the find -print0 argument causes the -I to
clone() for each file:
find . -name "x*" -print0 | strace xargs -0 -I '{}' mv '{}' /tmp/other
.
.
read(0, "./foobar1/xorgslsala11\0./foobar1"..., 4096) = 870
mmap(NULL, 135168, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fbb82fad000
open("/usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=26066, ...}) = 0
mmap(NULL, 26066, PROT_READ, MAP_SHARED, 3, 0) = 0x7fbb82fa6000
close(3) = 0
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fbb835af9d0) = 661
wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 661
--- SIGCHLD (Child exited) @ 0 (0) ---
clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fbb835af9d0) = 662
wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, NULL) = 662
--- SIGCHLD (Child exited) @ 0 (0) ---
.
.
.