Basic features of the Linux file system

1, file names are strictly case sensitive.

2, all files are located in the root directory, FHS.

3, the path is delimited by/.

4, each file name can use any character except '/', with a single name up to 255 characters long.

External command path view echo $PATH

View hit count hash: All hit external commands and times are rendered in tabular form.

Each absolute path can be split into two parts:

Base name: Basename/path/to/somewhere result is somewhere

Directory Name: dirname/path/to/somewhere result is/path/to

Bash's command history:

Histsize

Histfile

Histfilesize

Histcontrol

Ignoredups: Ignoring duplicate commands, repeating the same

Ignorespace: Ignore values that begin with a space

Ignoreboth: Both of these take effect at the same time

Reboot: Restart

Halt: Shut down the machine

Poweroff: Shut down the machine

Shutdown-r-h-p is actually implemented by invoking the above shutdown or restart command.

Date: Day and Time

date [options] [+format]

%s: Timestamp

%F,%d

Date [MMDDHHMM[[CC]YY][.SS]]

Linux two clocks: system clock, hardware clock

Hwclock

-S with hardware as the standard

-W to System

Ntp:network Time Protocol

Usage examples: date; Ntpdate 192.168.1.1

FHS Filesystem Hierarchy Standard

Bin:essential user Command binaries

boot:static files of the boot loader system boot loaded with the static file.

Cores and Ramdisk,grub (bootloader)

Dev:device files, Ls/dev shown in yellow, special files (only meta data, no data)

Etc:host-specifics system Configration

Home:user Home Directories

Root:home directory for the root user

Lib:essential shared libraries and kernel modules

Lib<qual> 64bit

Mnt:mount point for a temporarily mounted filesystem

Media:mount Point for Removeable Media

Opt:add-on Application Packages

Sbin:system binaries

Srv:data for services provided by this sytem

tmp:temporary files.

Selinux:security Enhanced Linux.

proc: In-memory running process abstraction for file representation, pseudo file system, kernel and process information for virtual files

System interface

sys: File form of pseudo file system, hardware device information

usr: After the system is loaded, the folder is the largest, Universal Shared read-only

Usr/bin: (Note the difference from \ Bin) The command that the user may use to complete certain operations while the system is running

Usr/lib

Usr/sbin

Usr/local

var: Files That change frequently

/var/log

/var/lib

/var/mail

/var/opt

/var/tmp

Misc: Miscellaneous

Components of the application:

Binary program

Library files

Configuration file

Help file

File type: Ls-l the first bit is

Normal file:-,f

Catalog file: D

Symbolic Link file: L (link)

Device files

Character device: C (linear device)

Block device: B (Random device)

Named pipes: P

Socket file: S

View File type: File/path/to/filename

Basic features of the Linux file system