[root@bigdata-server-02 /]# ps --help all Usage: ps [options] Basic options: -A, -e all processes -a all with tty, except session leaders a all with tty, including other users -d all except session leaders -N, --deselect negate selection r only runni…

ref:Linux / Unix Command: ls NAME ls - list directory contents SYNOPSIS ls [OPTION]... [FILE]... DESCRIPTION List information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuSUX nor --sort. Mandatory ar…

linux 内存清理/释放命令 You could find reference from here: http://jingyan.baidu.com/article/597a06436a687f312b5243f3.html Basically it looks like this: ---------------------------------- 清理前内存使用情况 free –m 或者 free 清理内存 > /proc/sys/vm/drop_caches 清理后内存使用情况 fr…

命令的语法通用格式: ------------------------------------------------ #COMMAND OPTIONS ARGUMENTS 发起命令:请求内核将某个二进制程序运行为一个进程: 程序 --> 进程 静态 --> 动态(有生命周期) 命令本身是一个可执行的程序文件:二进制格式的文件,有可能会调用共享库文件: 多数系统程序文件都存放在:/bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin, /usr/loc…

switch to root : sudo su switch to users : su god(user name) set root password : sudo passwd root check out kernel version : uname -r generate 'config.gz' file(the compressed package of '.config') : modprobe configs exit current thread: ctrl+c check…

1. 简介 1.1. 最近看到阿里的运维招聘需要熟练掌握以下的命令,我就针对这几个命令做一下总结,有些命令我觉得别人总结的挺好了,我就不赘述了 1.2. 还有一些其他我觉得用得到的命令的用法会在第三部分补充 2. 命令 2.1. tcpdump https://www.cnblogs.com/ggjucheng/archive/2012/01/14/2322659.html 2.2. strace 维基百科:https://en.wikipedia.org/wiki/Strace     htt…

文件管理工具:cp, mv, rm cp命令:copy 源文件:目标文件 单源复制:cp [OPTION]... [-T] SOURCE DEST 多源复制:cp [OPTION]... SOURCE... DIRECTORY cp [OPTION]... -t DIRECTORY SOURCE... 单源复制:cp [OPTION]... [-T] SOURCE DEST 如果DEST不存在:则实现创建此文件,并复制源文件的数据流至DSST中: 如果DEST存在: 如果DEST是非目录文件:则…

分屏查看命令:more和less more命令: more FILE 特点:翻屏至文件尾部后自动退出: less命令: less FILE head命令: 查看文件的前n行: head [option] FILE -n # -# tail命令: 查看文件的后n行: tail [option] FILE -n # -# -f:查看文件尾部内容后不退出,跟随显示新增的行 stat命令: stat - display file or file system status stat [OPTION]..…

1. 系统启动流程:POST --> Boot Sequeue(BIOS) --> Bootloader(MBR) --> Kernel(ramdisk) --> rootfs --> /sbin/init         init:             CentOS 5: SysV init             CentOS 6:Upstart             CentOS 7:Systemd               2. Systemd的新特性: 系统…

Memory Usage On linux, there are commands for almost everything, because the gui might not be always available. When working on servers only shell access is available and everything has to be done from these commands. So today we shall be checking th…