请问终端提示【Display all 315 possibilities？（y or n）】这个提示是什么意思呢？（虽然并不懂其中的意思，本人一个一个单词输入中...）

提示：输入法是：Unicode Hex Input

Display all 315 possibilities？（y or n）

！
look
./
Is
：
Isof
AssetCacheLocatorUtil
mDNSResponder
BootCacheControl
mDNSRespondetrHelper
KernelEventAgent
machine
NetBootClientStatus
md5
[
mkdir
[[
mkfifo
]]
mknod
alias
mktemp
apfs_hfs_convert
more
appsleepd
mount
arch
mount_9p
asctl
mount_afp
asr
mount_apfs
awk
mount_cd9660
banner
mount_cddafs
bash
mount_devfs
bg
mount_exfat
bind
mount_fdesc
bless
mount_hfs
bluetoothd
mount_hfs
break
mount_msdos
bsdtar
mount_nfs
builtin
mount_ntfs
bzegrep
mount_smbfs
bzfgrep
mount_udf
bzgrep
mount_webdav
caffeinate
mpioutil
caller
mv
case
nbdst
cat
nc
cd
netstat
cfprefsd
newfs_apfs
chflags
newfs_exfat
chmod
newfs_hfs
chown
newfs_msdos
chroot
newfs_udf
ckksctl
nfsd
cksum
nfsiod

codesign
-bash-3.2# codesign
Usage：codesign -s identify［-fv＊] [-o flags] [-r reqs] [-i ident] path . . .# sign
codesign -v [-v＊] [-R=|-R ] path｜[+]pid … # verify
codesign -d [options] path … # display contents
codesign -h pid … # display hosting paths
nl
col
nologin
colrm
notifyd
column
notifyutil
comm
nvram
command
ocspd
compgen
paste
complete
pax
continue
pdisk
coreaudiod
perl
cp
perl15.18
cpio
pfctl
csplit
ping
csrutil
ping6
curl
pkgutil
curl
pkgutil
cut
pl
date
plutil
dd
pmset

-bash-3.2# declare
BASH=/bin/sh
BASH_ARGC=( )
BASH_ARGC=( )
BASH_LINENO=( )
BASH_SOURCE=( )
BASH_VERSIONFO=( [0]=“3” [1]=“2” [2]=“57” [3]=“1” [4]=“release” [5]=“x86_64-apple-darwin18”）
CA_ASSERT_MAIN_THREAD_TRANSACTIONS=1
CI_DEFAULT_OPENCL_USAGE=0
COLUMNS=65
DIRSTACK=( )
DYLD_NO_FIX_PREBINDING=1
EUID=0
GROUPS=( )
HISTFILE=/var/root/.bash_history
HISTFILESIZE=500
HOME=/var/root
HOSTNAME=MacBook-Pro.local
HOSTTYPE=x86_64
IFS=$’＼t＼n＇
LANG=en_GB.UTF-8
LINES=37
MACHTYPE=x86_64-apple-darwin18
MAILCHECK=60
OPTERR=1
OPTIND=1
OSTYPE=darwin18
OS_INSTALL=1
PATH=/usr/bin:/bin:/usr/sbin:/sbin
PIPESTATUS=( [0]=“2” )
PPID=612
PS1=’\s-\v$＇
PS2=’> ＇
PS4=’+ ’
PWD=/private/var/root
SHELL=/bin/sh
SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
SHLVL=2
TERM=xterm-256color
TERM_PROGRAM=Appke_Terminal
TERM_PROGRAM_VERSION=421.2
TERM_SESSION_ID=31219818-0EB4-4D8C-A562-36AA45C47A2D
UID=0
XPC_FLAGS=0x0
XPC_SERVICE_NAME=0
_=codesign
_ _OSINSTALL_ENVIROMENT=1

popd
defaults
pr
dev_mkdb
printf
df
ps
dig
pushd
dirs
pwd
disklabel
quotacheck
disktool
raidutil
diskutil
read
disown
readonly
distnoted
reboot
ditto
repairHomePermissions
dmsg
resetFileVaultPassword
dnsextd
return
do
rev
done
rm
dscl
rmdir
dynamic_pager
route
echo
rs
ed
rtsol
egrep
sample
elif
sandbox-exec
else
scp
enable
scselect
esac
scustil
eval
security
exec
securityd
exit
sed
eapand
select
export
set
expr
sftool

false
-bash-3.2# false
-bash-3.2#

sh
-bash-3.2# sh
sh-3.2#

fc
shift
fdisk
shopt
fg
shutdown
fgrep
sleep
fi
sntp
fibreconfig
sort
filecoordinationd
source
follevaultRecovery
spctl
find
spindump
finger
split
fmt
ssh
fold
sshd
fontrestore
stat
for
stty
fsck
suspend
fsck_apfs
sw_vers
fsck_cs
sync
fsck_exfat
sysctl
fsck_hfs
syslogd
fsck_msdos
systemsoundserverd

fsck_udf

tail

fstyp

tar

fstyp_hfs

tccutil

fstyp_ntfs

then

fstyp_udf
sh-3.2# fstyp_udf
usage：fstyp_udf device

time
sh-3.2# time

real 0m0.001s
user 0m0.000s
sys 0m0.000s

function
sh-3.2# function
sh：syntax error near unexpected token `newline’

times
sh-3.2# times
0m0.008s 0m0.008s
0m0.003s 0m0.003s

getopt
sh-3.2# getout
– –

touch
sh-3.2# touch
usage:
touch [-A [-] [ [hh] mm]SS] [-acfhm] [-r file] [-t [ [CC]YY]MMDDhhmm[.SS]] file …

getopts

tr

gpt

traceroute

graphicssession

trap

grep

true

gssd

tset
halt
type
hash
typeset
hdid
ul
hdik
ulimit
hdiutil
umask
head
umount
help
unalias
hiatory
enexpand
hostinfo
uniq
hostname
unlink
if
unset
ifconfig
until
in
unvis
imstaller
update_dyld_shared_cache
ioreg
uuidgen
ipconfig
vi
jobs
vim
join
vis
kextcache
vsdbutil
kextload
wait
kextunload
wait4path
kill
wc
Iam
what
launchctl
while
launchd
whois
less
xar
let
xartutil
link
xartuil
In
zfgrep
local
zgrep
logger
{
login
｝
logout
sh-3.2# logout
sh: logout: not login shell: useexit' sh-3.2#exit’