[root@490de829cb74 ~]# grep '#' profile # /etc/profile # System wide environment and startup programs, for login setup # Functions and aliases go in /etc/bashrc # It's NOT a good idea to change this file unless you know what you # are doing. It's much better to create a custom.sh shell script in # /etc/profile.d/ to make custom changes to your environment, as this # will prevent the need for merging in future updates. # ksh workaround # Path manipulation # By default, we want umask to get set. This sets it for login shell # Current threshold for system reserved uid/gids is 200 # You could check uidgid reservation validity in # /usr/share/doc/setup-*/uidgid file if [ "${-#*i}" != "$-" ]; then
例2: 显示不包含#的行(使用-v进行反选)
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[root@490de829cb74 ~]# grep -v '#' profile pathmunge () { case":${PATH}:"in *:"$1":*) ;; *) if [ "$2" = "after" ] ; then PATH=$PATH:$1 else PATH=$1:$PATH fi esac }
if [ -x /usr/bin/id ]; then if [ -z "$EUID" ]; then EUID=`/usr/bin/id -u` UID=`/usr/bin/id -ru` ......
[root@490de829cb74 ~]# wc --help Usage: wc [OPTION]... [FILE]... or: wc [OPTION]... --files0-from=F Print newline, word, and byte counts for each FILE, and a total line if more than one FILE is specified. With no FILE, or when FILE is -, read standard input. -c, --bytes print the byte counts -m, --chars print the character counts -l, --lines print the newline counts --files0-from=F read input from the files specified by NUL-terminated names in file F; If F is - thenread names from standard input -L, --max-line-length print the length of the longest line -w, --words print the word counts --help display this help and exit --version output version information and exit
[root@490de829cb74 ~]# cp /etc/inittab ~ [root@490de829cb74 ~]# cat inittab # inittab is only used by upstart for the default runlevel. # # ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM. # # System initialization is started by /etc/init/rcS.conf # # Individual runlevels are started by /etc/init/rc.conf # # Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf # # Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf, # with configuration in /etc/sysconfig/init. # # For information on how to write upstart event handlers, or how # upstart works, see init(5), init(8), and initctl(8). # # Default runlevel. The runlevels used are: # 0 - halt (Do NOT set initdefault to this) # 1 - Single user mode # 2 - Multiuser, without NFS (The same as 3, if you do not have networking) # 3 - Full multiuser mode # 4 - unused # 5 - X11 # 6 - reboot (Do NOT set initdefault to this) # id:3:initdefault:
# 把模式设置为5; [root@490de829cb74 ~]# sed "s/\(id:\)[0-6]\(:initdefault:\)/\15\2/" inittab # inittab is only used by upstart for the default runlevel. # # ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM. # # System initialization is started by /etc/init/rcS.conf # # Individual runlevels are started by /etc/init/rc.conf # # Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf # # Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf, # with configuration in /etc/sysconfig/init. # # For information on how to write upstart event handlers, or how # upstart works, see init(5), init(8), and initctl(8). # # Default runlevel. The runlevels used are: # 0 - halt (Do NOT set initdefault to this) # 1 - Single user mode # 2 - Multiuser, without NFS (The same as 3, if you do not have networking) # 3 - Full multiuser mode # 4 - unused # 5 - X11 # 6 - reboot (Do NOT set initdefault to this) # id:5:initdefault:
扩展: inittab文件作用
确定在操作系统启动时, 进入的是哪个模式;
0-halt(Do Not set initdefault to this) 关机，请不要让默认init进程为0
[root@490de829cb74 ~]# cat awk.txt Tom 0 2012-12-11 cat 3000 John 1 2013-01-13 bike 1000 vivi 1 2013-01-18 car 2800 Tom 0 2013-01-20 cat 2500 John 1 2013-01-28 bike 3500
[root@490de829cb74 ~]# awk '{split($3,date, "-"); if(date[2]=="01"){name[$1]+=$5}} END{for(i in name){print i"\t"name[i]}}' awk.txt vivi 2800 Tom 2500 John 4500
先使用split($3,date, "-")通过-拆分第三列并放入date数组;
然后判断是否为一月份, 满足条件将数据放入name数组;
最后在END方法遍历输出name数据;
扩展: 表中0代表Manager, 1代表Worker; 输出关联查询结果
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[root@490de829cb74 ~]# awk '{split($3,date, "-"); if(date[2]=="01"){name[$1]+=$5}; if($2=="0"){role[$1]="M"} else{role[$1]="W"} } END{for(i in name){print i"\t"name[i]"\t"role[i]}}' awk.txt vivi 2800 W Tom 2500 M John 4500 W
