Access rights to the file. The first character indicates the type of file. Among the different types, a leading dash means a regular file, while a “d” indicates a directory. The next three characters are the access rights for the file's owner, the next three are for members of the file's group, and the final three are for everyone else. The full meaning of this is discussed in Chapter 10 – Permissions.
1
File's number of hard links. See the discussion of links later in this chapter.
root
The user name of the file's owner.
root
The name of the group which owns the file.
32059
Size of the file in bytes.
2007-04-03 11:05
Date and time of the file's last modification.
oo-cd-cover.odf
Name of the file.
常用目录
Drectory
Comments
/
The root directory.Where everything begins.
/bin
Contains binaries (programs) that must be present for the system to boot and run.
/boot
Contains the linux kernel, intial RAM disk image (for drivers needed at boot time), and the boot loader.Interesting files:/boot/grub/grub.conf or menu.lst, which are used to configure the boot loader./boot/vmlinuz,the linux kernel.
/dev
This is a special directory which contains device nodes. "Everything is a file" also applies to devices. Here is where the kernel maintains a list of all the devices it understands.
/etc
The /etc directory contains all of the system-wide configuration files. It also contains a collection of shell scripts which start each of the system services at boot time. Everything in this directory should be readable text.Interesting files:While everything in /etc is interesting, here are some of my all-time favorites:/etc/crontab, a file that defines when automated jobs will run./etc/fstab, a table of storage devices and their associated mount points./etc/passwd, a list of the user accounts.
/home
In normal configurations, each user is given a directory in /home. Ordinary users can only write files in their home directories. This limitation protects the system from errant user activity.
/lib
Contains shared library files used by the core system programs. These are similar to DLLs in Windows.
/lost+found
Each formatted partition or device using a Linux file system, such as ext3, will have this directory. It is used in the case of a partial recovery from a file system corruption event. Unless something really bad has happened to your system, this directory will remain empty.
/media
On modern Linux systems the /media directory will contain the mount points for removable media such USB drives, CD-ROMs, etc. that are mounted automatically at insertion.
/mnt
On older Linux systems, the /mnt directory contains mount points for removable devices that have been mounted manually.
/opt
The /opt directory is used to install “optional” software. This is mainly used to hold commercial software products that may be installed on your system.
/proc
The /proc directory is special. It's not a real file system in the sense of files stored on your hard drive. Rather, it is a virtual file system maintained by the Linux kernel. The “files” it contains are peepholes into the kernel itself. The files are readable and will give you a picture of how the kernel sees your computer.
/root
This is the home directory for the root account.
/sbin
This directory contains “system” binaries. These are programs that perform vital system tasks that are generally reserved for the superuser.
/tmp
The /tmp directory is intended for storage of temporary, transient files created by various programs. Some configurations cause this directory to be emptied each time the system is rebooted.
/usr
The /usr directory tree is likely the largest one on a Linux system. It contains all the programs and support files used by regular users.
/usr/bin
/usr/bin contains the executable programs installed by your Linux distribution. It is not uncommon for this directory to hold thousands of programs.
/usr/lib
The shared libraries for the programs in /usr/bin.
/usr/local
The /usr/local tree is where programs that are not included with your distribution but are intended for system- wide use are installed. Programs compiled from source code are normally installed in /usr/local/bin. On a newly installed Linux system, this tree exists, but it will be empty until the system administrator puts something in it.
/usr/sbin
Contains more system administration programs.
/usr/share
/usr/share contains all the shared data used by programs in /usr/bin. This includes things like default configuration files, icons, screen backgrounds, sound files, etc.
/usr/share/doc
Most packages installed on the system will include some kind of documentation. In /usr/share/doc, we will find documentation files organized by package.
/var
With the exception of /tmp and /home, the directories we have looked at so far remain relatively static, that is, their contents don't change. The /var directory tree is where data that is likely to change is stored. Various databases, spool files, user mail, etc. are located here.
/var/log
/var/log contains log files, records of various system activity. These are very important and should be monitored from time to time. The most useful one is /var/log/messages. Note that for security reasons on some systems, you must be the superuser to view log files.
An executable program like all those files we saw in /usr/bin. Within this category, programs can be compiled binaries such as programs written in C and C++, or programs written in scripting languages such as the shell, perl, python, ruby, etc.
A command built into the shell itself. bash supports a number of commands internally called shell builtins. The cd command, for example, is a shell builtin.
A shell function. These are miniature shell scripts incorporated into the environment. We will cover configuring the environment and writing shell functions in later chapters, but for now, just be aware that they exist.
An alias. Commands that we can define ourselves, built from other commands.
IO命令
cat - Concatenate files
sort - Sort lines of text
uniq - Report or omit repeated lines
grep - Print lines matching a pattern
wc - Print newline, word, and byte counts for each file
head - Output the first part of a file
tail - Output the last part of a file
tee - Read from standard input and write to standard output and files
2019.08.12
常用命令的英语
常用目录
2019.08.13
到底什么是命令--命令可以是下面4种形式(用type判断类型)
An executable program like all those files we saw in /usr/bin. Within this category, programs can be compiled binaries such as programs written in C and C++, or programs written in scripting languages such as the shell, perl, python, ruby, etc.
A command built into the shell itself. bash supports a number of commands internally called shell builtins. The cd command, for example, is a shell builtin.
A shell function. These are miniature shell scripts incorporated into the environment. We will cover configuring the environment and writing shell functions in later chapters, but for now, just be aware that they exist.
An alias. Commands that we can define ourselves, built from other commands.
IO命令
标准输出重定向
2019.08.14
2019.10.2 好久没看了，下一步把这个看完顺便试试github hook