Linux常用命令（一） 基础

查看用户标识和组标识

[amonest@centos-server ~]$ id
uid=500(amonest) gid=500(amonest) groups=500(amonest),10(wheel) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

查看当前登录到系统的用户

[amonest@centos-server ~]$ who
amonest pts/0 2012-07-13 17:59 (c60601199.xxxx.com)

查看机器在启动日期肯时间

[amonest@centos-server ~]$ who -b
system boot 2012-07-13 16:49

查看机器运行时间

[amonest@centos-server ~]$ uptime
18:15:04 up 1:25, 1 user, load average: 0.00, 0.00, 0.00

查看机器运行时间和登录用户

[amonest@centos-server ~]$ w
18:16:10 up 1:27, 1 user, load average: 0.00, 0.00, 0.00
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
amonest pts/0 c60601199.xxxxx. 17:59 0.00s 0.07s 0.00s w

查看系统硬盘空间信息

[amonest@centos-server /etc]$ df -ah
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 18G 6.3G 11G 39% /
proc 0 0 0 - /proc
sysfs 0 0 0 - /sys
devpts 0 0 0 - /dev/pts
tmpfs 499M 0 499M 0% /dev/shm
/dev/sda1 485M 31M 429M 7% /boot
none 0 0 0 - /proc/sys/fs/binfmt_misc

查看系统进程信息

[amonest@centos-server /etc]$ ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 16:49 ? 00:00:01 /sbin/init
root 2 0 0 16:49 ? 00:00:00 [kthreadd]
root 3 2 0 16:49 ? 00:00:00 [migration/0]
root 4 2 0 16:49 ? 00:00:00 [ksoftirqd/0]
root 5 2 0 16:49 ? 00:00:00 [migration/0]
root 6 2 0 16:49 ? 00:00:00 [watchdog/0]
root 7 2 0 16:49 ? 00:00:00 [events/0]

显示进程树

[amonest@centos-server ~]$ pstree -a
init
├─auditd
│ └─{auditd}
├─avahi-daemon
│ └─avahi-daemon
├─crond
├─rsyslogd -i /var/run/syslogd.pid -c 4
│ ├─{rsyslogd}
│ ├─{rsyslogd}
│ └─{rsyslogd}
├─sshd
│ └─sshd
│ └─sshd
│ └─bash
│ └─pstree -a
└─udevd -d
├─udevd -d
└─udevd -d

在man page中搜索某个关键词(仅限在命令名称中搜索)

[amonest@centos-server ~]$ man -f avahi
avahi-daemon (8) - The Avahi mDNS/DNS-SD daemon
avahi-daemon.conf [avahi-daemon] (5) - avahi-daemon configuration file
avahi.hosts [avahi] (5) - avahi-daemon static host name file
avahi.service [avahi](5) - avahi-daemon static service file

在man page中搜索某个关键词(在命令名称和命令说明中搜索)

[amonest@centos-server ~]$ man -k print
arch (1) - print machine hardware name (same as uname -m)
base64 (1) - base64 encode/decode data and print to standard output
blkid (8) - command-line utility to locate/print block device attributes
cat (1) - concatenate files and print on the standard output
consoletype (1) - print type of the console connected to standard input
date (1) - print or set the system date and time

查询某个包是否已经安装：

[amonest@centos-server ~]$ rpm -qa | grep -i ssh
openssh-server-5.3p1-70.el6.x86_64
libssh2-1.2.2-7.el6_1.1.x86_64
openssh-5.3p1-70.el6.x86_64
openssh-askpass-5.3p1-70.el6.x86_64
openssh-clients-5.3p1-70.el6.x86_64

查询某个包的配置文件：

[amonest@centos-server ~]$ rpm -qc openssh-server
/etc/pam.d/ssh-keycat
/etc/pam.d/sshd
/etc/ssh/sshd_config
/etc/sysconfig/sshd