.         Nhؿ
..        NW@hؿ
-         Ne@Ӥu@ؿ
~         NyثeϥΪ̨zҦbaؿ
~account  N account oӨϥΪ̪aؿ

[root@linux ~]# echo $PATH
/sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin

[root@linux ~]# ls [-aAdfFhilRS] ؿW
[root@linux ~]# ls [--color={none,auto,always}] ؿW
[root@linux ~]# ls [--full-time] ؿW
ѼơG
-a  GɮסAsP( }Y . ɮ) @_CXӡ
-A  GɮסAsPɡA]A . P .. oӥؿA@_CXӡ
-d  GȦCXؿAӤOCXؿɮ׸
-f  GCXGAӤiƧ (ls w]|HɦWƧǡI)
-F  GھɮסBؿTA[ƵcAҦpG
      *GNiɡF /GNؿF =GN socket ɮסF |GN FIFO ɮסF
-h  GNɮ׮eqHHŪ觋(Ҧp GB, KB )CXӡF
-i  GCX inode mAӫDCXɮݩʡF
-l  GƦCXA]tɮתݩʵơF
-n  GCX UID P GID ӫDϥΪ̻PsժW (UIDPGID|bb޲zI)
-r  GNƧǵGϦVXAҦpG쥻ɦWѤpjAϦVhѤjpF
-R  GsPlؿe@_CXӡF
-S  GHɮ׮eqjpƧǡI
-t  G̮ɶƧ
--color=never  Gn̾ɮׯSʵCܡF
--color=always GC
--color=auto   GtΦۦ̾ڳ]wӧP_O_C
--full-time    GHɶҦ (]t~BBBɡB) X
--time={atime,ctime} GX access ɶ vݩʮɶ (ctime) 
                       ӫDeܧɶ (modification time)
dҡG

dҤ@GNaؿUҦɮצCX(tݩʻP)
[root@linux ~]# ls -al ~
total 252
drwxr-x---   9 root root  4096 Jul 16 23:40 .
drwxr-xr-x  24 root root  4096 Jul 16 23:45 ..
-rw-------   1 root root  1491 Jun 25 08:53 anaconda-ks.cfg
-rw-------   1 root root 12543 Jul 18 01:23 .bash_history
-rw-r--r--   1 root root    24 Dec  4  2004 .bash_logout
-rw-r--r--   1 root root   191 Dec  4  2004 .bash_profile
-rw-r--r--   1 root root   395 Jul  4 11:45 .bashrc
-rw-r--r--   1 root root 68495 Jun 25 08:53 install.log
-rw-r--r--   1 root root  5976 Jun 25 08:53 install.log.syslog
drwx------   2 root root  4096 Jul  4 16:03 .ssh
-rw-------   1 root root 12613 Jul 16 23:40 .viminfo
# oӮɭԱz|ݨH . }YXɮסAHΥؿ ./../.ssh A
# LAؿɳOH`ŦܡAIeݲMNOFC

dҤGGӤWDACAbɦWܥXɦWN(type)
[root@linux ~]# ls -alF --color=never  ~
total 252
drwxr-x---   9 root root  4096 Jul 16 23:40 ./
drwxr-xr-x  24 root root  4096 Jul 16 23:45 ../
-rw-------   1 root root  1491 Jun 25 08:53 anaconda-ks.cfg
-rw-------   1 root root 12543 Jul 18 01:23 .bash_history
-rw-r--r--   1 root root    24 Dec  4  2004 .bash_logout
-rw-r--r--   1 root root   191 Dec  4  2004 .bash_profile
-rw-r--r--   1 root root   395 Jul  4 11:45 .bashrc
-rw-r--r--   1 root root 68495 Jun 25 08:53 install.log
-rw-r--r--   1 root root  5976 Jun 25 08:53 install.log.syslog
drwx------   2 root root  4096 Jul  4 16:03 .ssh/
-rw-------   1 root root 12613 Jul 16 23:40 .viminfo
# `NݨܵGĤ@AKK㪾Dڭ̷|UF ./command 
# OFaH] ./ NOyثeؿUzNڡIܩ󤰻O FIFO/Socket H
# аѦҫe@`аڡI

dҤTG㪺e{ɮתקɶ *(modification time)
[root@linux ~]# ls -al --full-time  ~
total 252
drwxr-x---   9 root root  4096 2005-07-16 23:40:13.000000000 +0800 .
drwxr-xr-x  24 root root  4096 2005-07-16 23:45:05.000000000 +0800 ..
-rw-------   1 root root  1491 2005-06-25 08:53:37.000000000 +0800 anaconda-ks.cfg
-rw-------   1 root root 12543 2005-07-18 01:23:33.000000000 +0800 .bash_history
-rw-r--r--   1 root root    24 2004-12-04 05:44:13.000000000 +0800 .bash_logout
-rw-r--r--   1 root root   191 2004-12-04 05:44:13.000000000 +0800 .bash_profile
-rw-r--r--   1 root root   395 2005-07-04 11:45:16.000000000 +0800 .bashrc
-rw-r--r--   1 root root 68495 2005-06-25 08:53:34.000000000 +0800 install.log
-rw-r--r--   1 root root  5976 2005-06-25 08:53:28.000000000 +0800 install.log.syslog
drwx------   2 root root  4096 2005-07-04 16:03:24.000000000 +0800 .ssh
-rw-------   1 root root 12613 2005-07-16 23:40:13.000000000 +0800 .viminfo
# ХJӬݡAWyɶzܤFIܦ㪺榡C
# @ӻA ls -al ȦCXثeu榡ɶAɤ|CX~A
# ǥ --full-time iHd\Tɶ榡ڡI

[root@linux ~]# basename /etc/sysconfig/network
network  <== ²INo̫᪺ɦW
[root@linux ~]# dirname /etc/sysconfig/network
/etc/sysconfig  <== oܦؿWFI

[root@linux ~]# od [-t TYPE] ɮ
ѼơG
-t  G᭱iHUءy (TYPE)zXAҦpG
      a       GQιw]rӿXF
      c       Gϥ ASCII rӿX
      d[size] GQΤQi(decimal)ӿXơACӾƦ size bytes F
      f[size] GQίBIƭ(floating)ӿXơACӼƦ size bytes F
      o[size] GQΤKi(octal)ӿXơACӾƦ size bytes F
      x[size] GQΤQi(hexadecimal)ӿXơACӾƦ size bytes F
dҡG
[root@linux ~]# od -t c /usr/bin/passwd
0000000 177   E   L   F 001 001 001  \0  \0  \0  \0  \0  \0  \0  \0  \0
0000020 002  \0 003  \0 001  \0  \0  \0 260 225 004  \b   4  \0  \0  \0
0000040 020   E  \0  \0  \0  \0  \0  \0   4  \0      \0  \a  \0   (  \0
0000060 035  \0 034  \0 006  \0  \0  \0   4  \0  \0  \0   4 200 004  \b
0000100   4 200 004  \b 340  \0  \0  \0 340  \0  \0  \0 005  \0  \0  \0
.....ٲ.......

[root@linux ~]# ls -l /etc/man.config
-rw-r--r--  1 root root 4506 Apr  8 19:11 /etc/man.config
[root@linux ~]# ls -l --time=atime /etc/man.config
-rw-r--r--  1 root root 4506 Jul 19 17:53 /etc/man.config
[root@linux ~]# ls -l --time=ctime /etc/man.config
-rw-r--r--  1 root root 4506 Jun 25 08:28 /etc/man.config

[root@linux ~]# touch [-acdmt] ɮ
ѼơG
-a  Gȭ׭q access timeF
-c  GȭקɶAӤإɮסF
-d  G᭱iHA]iHϥ --date="ήɶ"
-m  Gȭק mtime F
-t  G᭱iHɶA榡[YYMMDDhhmm]
dҡG

dҤ@Gsؤ@ӪŪɮ
[root@linux ~]# cd /tmp
[root@linux tmp]# touch testtouch
[root@linux tmp]# ls -l testtouch
-rw-r--r--  1 root root    0 Jul 19 20:49 testtouch
# `NAoɮתjpO 0 OIbw]AUApG touch ᭱ɮסA
# hɮתTӮɶ (atime/ctime/mtime) |sثeɶCYɮפsbA
# h|Dʪإߤ@ӷsŪɮ׳IҦpWoӨҤlI

dҤGGN ~/.bashrc ƻs bashrcA]ƻsݩʡAˬd
[root@linux tmp]# cp ~/.bashrc bashrc
[root@linux tmp]# ll bashrc; ll --time=atime bashrc; ll --time=ctime bashrc
-rwxr-xr-x  1 root root 395 Jul  4 11:45 bashrc  <==oO mtime
-rwxr-xr-x  1 root root 395 Jul 19 20:44 bashrc  <==oO atime
-rwxr-xr-x  1 root root 395 Jul 19 20:53 bashrc  <==oO ctime
# boӮרҷAڭ̨ϥΤF ; oӫOjŸALΪkڭ̷|b Bash shell C
# ~A ll O ls -l ROOWAoӧڭ̤]|b bash shell AΡA
# zثeiH²檺QA ll NO ls -l ²gYiIܩ ; hOPɤUFӫOA
# BӫOy̧ǡz檺NCWGڭ̥iHݨAɮܧ󪺤
# Jul 4 11:45AO atime P ctime @o

dҤTGקרҤG bashrc ɮסANվ㬰ѫe
[root@linux tmp]# touch -d "2 days ago" bashrc
[root@linux tmp]# ll bashrc; ll --time=atime bashrc; ll --time=ctime bashrc
-rwxr-xr-x  1 root root 395 Jul 17 21:02 bashrc
-rwxr-xr-x  1 root root 395 Jul 17 21:02 bashrc
-rwxr-xr-x  1 root root 395 Jul 19 21:02 bashrc
# WӽdҤݬݡAӬO 19 骺ܦF 17 F (atime/mtime)
# LA ctime èSۧܳI

dҥ|GNWӽdҪ bashrc אּ 2005/07/15 2:02
[root@linux tmp]# touch -t 0507150202 bashrc
[root@linux tmp]# ll bashrc; ll --time=atime bashrc; ll --time=ctime bashrc
-rwxr-xr-x  1 root root 395 Jul 15 02:02 bashrc
-rwxr-xr-x  1 root root 395 Jul 15 02:02 bashrc
-rwxr-xr-x  1 root root 395 Jul 19 21:05 bashrc
# `NݬݡAb atime P mtime ܤFAO ctime hOOثeɶI

[root@linux ~]# umask
0022
[root@linux ~]# umask -S
u=rwx,g=rx,o=rx

[root@linux ~]# umask
0022
[root@linux ~]# touch test1
[root@linux ~]# mkdir test2
[root@linux ~]# ll 
-rw-r--r--  1 root root    0 Jul 20 00:36 test1
drwxr-xr-x  2 root root 4096 Jul 20 00:36 test2

[root@linux ~]# umask 002
[root@linux ~]# touch test3
[root@linux ~]# mkdir test4
[root@linux ~]# ll 
-rw-rw-r--  1 root root    0 Jul 20 00:41 test3
drwxrwxr-x  2 root root 4096 Jul 20 00:41 test4

[root@linux ~]# ls -ld /tmp ; ls -l /usr/bin/passwd
drwxrwxrwt  5 root root 4096 Jul 20 10:00 /tmp
-r-s--x--x  1 root root 18840 Mar  7 18:06 /usr/bin/passwd

[root@linux ~]# file ~/.bashrc
/root/.bashrc: ASCII text  <== iDڭ̬O ASCII ¤rɰڡI
[root@linux ~]# file /usr/bin/passwd
/usr/bin/passwd: setuid ELF 32-bit LSB executable, Intel 80386, version 1 
(SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), stripped
# ƥihF]AoӤ Set UID 2ɮסAϥ shared libsA
# AX Intel  386 HWتwAܲMaI
[root@linux ~]# file /var/lib/slocate/slocate.db
/var/lib/slocate/slocate.db: data  <== oO data ɮסI

[root@linux ~]# which [-a] command
ѼơG
-a GNҦiH쪺OCXAӤĤ@ӳQ쪺OW
dҡG
[root@linux ~]# which passwd
/usr/bin/passwd
[root@linux ~]# which traceroute -a
/usr/sbin/traceroute
/bin/traceroute

[root@linux ~]# whereis [-bmsu] ɮשΥؿW
ѼơG
-b    :u binary ɮ
-m    :ub manual |Uɮ
-s    :u source ӷɮ
-u    :SɪɮסI
dҡG
[root@linux ~]# whereis passwd
passwd: /usr/bin/passwd /etc/passwd /etc/passwd.OLD 
/usr/share/man/man1/passwd.1.gz /usr/share/man/man5/passwd.5.gz
# P passwd ɦW|QCXӡ

[root@linux ~]# whereis -b passwd
passwd: /usr/bin/passwd /etc/passwd /etc/passwd.OLD

[root@linux ~]# whereis -m passwd
passwd: /usr/share/man/man1/passwd.1.gz /usr/share/man/man5/passwd.5.gz

[root@linux ~]# locate filename
[root@linux ~]# locate passwd
/lib/security/pam_passwdqc.so
/lib/security/pam_unix_passwd.so
/usr/lib/kde3/kded_kpasswdserver.so
/usr/lib/kde3/kded_kpasswdserver.la
.......ٲ.......

[root@linux ~]# find [PATH] [option] [action]
ѼơG
1. PɶѼơG
   -atime n Gn ƦrANqb n Ѥey@ѤzQ access LɮסF
   -ctime n Gn ƦrANqb n Ѥey@ѤzQ change LAɮסF
   -mtime n Gn ƦrANqb n Ѥey@ѤzQ modification LɮסF
   -newer file Gfile @ӦsbɮסANOAunɮפ file ٭nsA
                 N|QCXӡ
2. PϥΪ̩θsզW٦ѼơG
   -uid n Gn ƦrAoӼƦrOϥΪ̪b IDAY UID Ao UID OOb
            /etc/passwd ̭PbWٹƦrCo譱ڭ̷|bĥ|gСC
   -gid n Gn ƦrAoӼƦrOsզW٪ IDAY GIDAo GID Ob
            /etc/groupAЧڭ̷|ĥ|g
   -user name Gname ϥΪ̱bWٳIҦp dmtsai 
   -group nameGname sզWٳAҦp users F
   -nouser    GMɮת֦̤sb /etc/passwd HI
   -nogroup   GMɮת֦sդsb /etc/group ɮסI
                zۦw˳nɡAܥiӳn骺ݩʷèSɮ׾̡֦A
                oOi઺IboӮɭԡANiHϥ -nouser P -nogroup jMC
3. PɮvΦW٦ѼơG
   -name filenameGjMɮצW٬ filename ɮסF
   -size [+-]SIZEGjM SIZE ٭nj(+)Τp(-)ɮסCo SIZE W榳G
                   c: N byteA k: N 1024bytesCҥHAn 50KB
                   ٭njɮסANOy -size +50k z
   -type TYPE    GjMɮת TYPE ADnG@륿Wɮ (f),
                   ˸mɮ (b, c), ؿ (d), s (l), socket (s), 
                    FIFO (p) ݩʡC
   -perm mode  GjMɮݩʡynz mode ɮסAo mode  chmod
                 ݩʭȡA|ҨӻA -rwsr-xr-x ݩʬ 4755 I
   -perm -mode GjMɮݩʡynnA mode ݩʡzɮסA|ҨӻA
                 ڭ̭njM -rwxr--r-- AY 0744 ɮסAϥ -perm -0744A
                 @ɮתݩʬ -rwsr-xr-x AY 4755 ɡA]|QCXӡA
                 ] -rwsr-xr-x ݩʤwgnAF -rwxr--r-- ݩʤFC
   -perm +mode GjMɮݩʡy]t@ mode ݩʡzɮסA|ҨӻAڭ̷jM
                 -rwxr-xr-x AY -perm +755 ɡA@ɮݩʬ -rw-------
                 ]|QCXӡA]L -rw.... ݩʦsbI
4. B~ii檺ʧ@G
   -exec command Gcommand LOA-exec ᭱iAB~OӳBzjM
                   GC
   -print        GNGCLùWAoӰʧ@Ow]ʧ@I
dҡG
dҤ@GNLhtΤW 24 pɤʹLe (mtime) ɮצCX
[root@linux ~]# find / -mtime 0
#  0 OII0 NثeɶAҥHAq{b}l 24 pɫeA
# ܰʹLeɮ׳|QCXӡIpGOTѫe 24 pɤH
# find / -mtime 3 ANOѤe 3*24 ~ 4*24 pɤ
# ܰʹLɮ׳QCXNIP -atime P -ctime ΪkۦPC

dҤGGM /etc UɮסApGɮפ /etc/passwd sNCX
[root@linux ~]# find /etc -newer /etc/passwd
# -newer ΦbɮפsYOܦΪI

dҤTGjM /home Uݩ dmtsai ɮ
[root@linux ~]# find /home -user dmtsai
# oӪF]ܦΪڭ̭nX@ӨϥΪ̦btηҦɮ׮ɡA
# NiHQγoӫONݩYӨϥΪ̪Ҧɮ׳XӳI

dҥ|GjMtΤݩHɮ
[root@linux ~]# find / -nouser
# zLoӫOAiHNXǤӥ`ɮסC
# pG줣ݩtΥHɮ׮ɡAnӺiA
# ɭԬO`רOzgHlXۦsĶnɡC

dҤGXɦW passwd oɮ
[root@linux ~]# find / -name passwd
# Qγo -name iHjMɦWڡI

dҤGjMɮݩʬ f (@ɮ) ɮ
[root@linux ~]# find /home -type f
# o -type ݩʤ]ܦUIרOnXǩDzɮסA
# Ҧp socket P FIFO ɮסAiH find /var -type p  -type s ӧI

dҤCGjMɮ׷t SGID/SUID/SBIT ݩ
[root@linux ~]# find / -perm +7000 
# ҿת 7000 NO ---s--s--t Aunt s  t NCXA
# ҥHMnϥ +7000 Aϥ -7000 ܭnt ---s--s--t ҦTvA
# ]ANO +7000 AGH

dҤKGNWӽdҧ쪺ɮרϥ ls -l CXӡ
[root@linux ~]# find / -perm +7000 -exec ls -l {} \;
# `NA -exec ᭱ ls -l NOB~OA
# Ө {} NOy find 쪺ezNҥHA -exec ls -l {}
# NONe쪺ɮץH ls -l CXơIܩ \; hO
# -exec O즹NNOAӫOub 
# -exec (̭NOOUF) \;
# ]NOA-exec ̫@wnH \; ~IoAѤFܡHI

dҤEGXtΤAj 1MB ɮ
[root@linux ~]# find / -size +1000k
# Mb man page iHϥ M P G ON MB P GBA
# LAͫoդXӳoӥ\ҥHAثeӬOȤ䴩 c P k aI