TCN virtual currency
Publish: 2021-04-30 23:23:01
1. Taurus is a virtual currency, not a legal currency. At present, there are many people who use virtual currency for fraud and pyramid selling. Please be careful. Remember: there is no pie in the sky. The bigger the propaganda, the more likely it is to be a pit.
2. Common commands of UNIX system
common command formats of UNIX system:
command [flags] [argument1] [argument2]...
where flags start with - and multiple flags can be connected with one -, for example, LS - L - A is the same as LS - La
according to different commands, parameters can be divided into optional or required ones; All commands are input from the standard input, the output
results are displayed in the standard output, and the error information is displayed in the standard error output device. You can use the redirection function to redirect
these devices
the command returns a value of 0 after the normal execution result. If the command fails to complete completely, it returns a value of
non-zero (variable $? Can be used in shell)? This return value can be used as a part of control logic
in shell script
note: different UNIX versions may have different flags<
1. User related commands
1.1 login
(in Linux RedHat, the function of this command is different from Solaris / BSD, and login will exit the current task).
login:
password:
related files:
set the necessary path and terminal type in the following files, Other variables or special programs.
$home /. Profile (Bourne shell, SH, bash)
$home /. Cshrc (CSH, tcsh)
$home /. Tcshrc (tcsh)
/ etc / passwd file lists the shell of each user
/ etc / CSH. Cshrc
/ etc / CSH. Login
/ etc / profile (Bourne shell, bash)
/ etc / login (Bourne shell, bash)
/ etc / login (Bourne shell, Bash)
CSH: / etc / csh.cshrc and $home /. Cshrc are read every time they are executed,
while / etc / csh.login and $home /. Login are only executed by registered shell.
after modifying the corresponding files, use source.cshrc to enable relevant modifications. If the path is modified,
you need to use rehash to refresh the executable hash table
tcsh: $home /. Tcshrc, no files read. Cshrc
sh: / etc / profile and $home /. Profile register shell
bash: / etc / profile and $home /. Bash_ Profile registered shell read
. Bashrc interactive unregistered shell read
execute related files manually under SH / bash:
. / etc / profile
execution order of related files
sh: / etc / profile - & gt$ HOME/.profile
csh/tcsh: /etc/csh.cshrc -> / etc/csh.login -> $ HOME/.cshrc
-> $ Home /. Login
variable setting:
SH / bash: term = VT100; Export term
or: export term = VT100 (bash)
CSH: setenv term VT100
common variables:
(1) backspace $home /. Profile $home /. Cshrc
stty erase ^ H
(2) umask new file or directory protection attributes
(3) term
(4) avoid adding in path.
1.2. Rlogin
similar to telnet, Connect to the remote host.
rlogin remotehost [- L loginname]
or:
RSH [- L loginname] remotehost [command]
related files:
remote host's / etc / hosts.equiv and $home /. Rhosts
related network configuration files:
/ etc / inetd.conf R system services. In RedHat, shell, login, exec and, The network daemons corresponding to
are in.rshd, in.rlogind, in.rexecd.
suggestion: from the perspective of security, Close R series services.
1.3. Telnet
telnet remotehost [port]
related files:
/ etc / inetd.conf file.
/ etc / issue.net
tips: Strings / usr / SBIN / in. Telnetd | egrep issue
1.4. Passwd change password
1.5 exit exit current shell
2. Search command or file
2 />Related shell variables:
CSH / tcsh: $path
. Cshrc set path = (/ usr / bin / usr / local / bin $path)
SH / bash: $path
. Profile. Bash_ profile
PATH=/usr/local/bin:$PATH; Export path
2.1 which
syntax: which command
which is the built-in command of bash / tcsh
[ hbwork@toshiba ]$which
which: shell build in command.
2.2 where (tcsh)
syntax: where command
2.3 locate (Linux)
syntax: locate file name
related commands: updatedb change locate file name database < B R / >
3. View command usage
man
related files:
/ etc / man. Config
4. Administrator's common command
4.1 install
is used to install a new command or daemon, etc, However, many software use install to the target file to the corresponding directory and set the correct attributes in its installation
shell script.
name
install - files and set their attributes
synopsis
install [options] [- S] [- strip] source dest
install [options] [- S] [- strip] source... Directory
install [options] [- D, - Directory] Directory...
Options:
[- C] [g group] [M mode] [O owner] [group = group]
[- mode = mode] [owner = owner] [help] [version]
4.2 shutdown
different UNIX parameters are different, The following shutdown methods are commonly used in Linux:
shutdown - h now
shutdown - r now (equivalent to boot)
4.3 halt
poweroff
shutdown. It is not recommended in multi-user mode (runlevel 3).
4.4 ulimit
this command can be used in Korn shell and Bourne shell, In CSH series, the corresponding command is limit.
used to limit the system resources that can be used by each process. There are usually two kinds of restrictions:
. For the resources defined by hard limits system, only root can change
, Hard limit that can be added to the system.
flags:
- a lists soft limits
- ha lists hard limit
- C size sets the block size of coremp size
- t size cputime
- f size file size
4.5 umask system administrators use to set the user's default umask value.
5. Process related commands
basic concept of process: process and process Command execution is related, but not one-to-one correspondence; A command may correspond to several
processes (such as shell script, pipe, etc.), but the simplest command and umask have only one process.
process classification:
. Interactive process: can be executed in the foreground or background, and can be switched between the foreground and the background, Generally, they are executed sequentially in the task queue, such as tasks submitted through
at and crontab.
. Deamon: processes that never terminate, waiting to respond to service requests from other processes, such as sendmail,
named (DNS),
, POP3 and Apache, etc.
process related attributes:
PID
Real uid
effective uid (suid)
Real GID
effective GID (sgid)
priority (nice number) execution priority
5.1 ps
process status, which lists the current running process status, according to different options, All or part of the processes can be listed
. If there is no option, only the process (SYSV) started from the current terminal or the process (BSD) of the current user ($user) can be listed, There are differences between different UNIX versions. Linux uses BSD version of ps
. How to use BSD version of PS command:
ps
PS aux lists the details of all processes in the system
PS aux | egrep inetd
output information content:
PID
terminal if there is no corresponding terminal -
CPU time
userid or username
process start time Or date
process status (STAT: s (LEEP) r (unnable) d (uninterrupt sleep) Z (omnie)
W process has no resident page, N: process's nice value is negative
5.2 kill
kill [- signal] PID
kill - L list available semaphores
common information:
- HUP (1) restart process
PS ax | egrep inetd
kill - HUP PID_ of_ Inetd
- kill (9) forced stop
PID value meaning:
& gt; 0 refers to a specific process (actual process)
= 0 all process (PGID) of users in the same group
= - 1 effective uid = uid of user executing command
& lt; 0 && != 1 process with absolute value
5.3 nice
is used to change the priority of one or more processes; But only root or raise the priority of the process, ordinary users can only
lower the priority of the process.
nice uses a negative number to raise the priority, while a positive number to lower the priority. Generally, the value range is - 20 ~ 20.
if the priority is not specified, the process can be upgraded, Nice will rece or not change the priority of the process. Of course, if you do not have permission,
the priority of the process will not change.
generally, we use nice to rece the priority of the background process (the default priority is 10).
nice find. - name & quot; * c" - print &
nice 16 find . -name "*. c" - Print &
5.4 wait
wait PID
the parameter is PID, which is sometimes used in shell script.
5.5 nohup
nohup Command &
5.6 sleep
sleep seconds
switch between front and back stages of process: Ctrl-Z, FG, BG
6. Communication
6.1 FTP
6.2 mailx
6.3 minicom (serial terminal, modem)
7. File comparison
CMP
comm
diff (for comparing text files)
diff3 (for comparing three files)
sdiff
8. File operation
touch to create a file, Modify the file date, etc.
Chmod
chwon
chgrp
RM use RM - RF
MV to move the file or change its name
CP CP - R directory
cat
RCP remote
ln the default is hard connection, Each file has the same inode
ln - s Sourcefile targetfile
9. Directory operation
MKDIR [- P] [M mode] directory
rmdir [- P] directory
10. File information command
LS
find
the most basic function is to find a file name or directory, The common formats are as follows:
find. - Print (similar to LS - LR)
find can use the following attributes to find:
- name to find the file name, including wildcards *? The file name of is enclosed in quotation marks
- perm 00x000 octal file attribute
- atime file accessed n days ago
- Mtime file modified n days ago
- CTime n file status modified n days ago
- exec command if the return code of the command is zero (find the corresponding file), the command must be in the form of
\; As a result, in addition, {} is the path name of the found file ring the execution of the command,
- OK command is similar to exec, but the user is required to confirm that
- print prints the current path name
- new filename. If the last modification date of the file is newer than the filename, it is true
- type C = [b, C, D, l, P, f] File type
- user userif the owner of the file is username, it is true
- nouser file owner does not exist in / etc / passwd file
- group growname file group
logical operator: - A - O
List:
find $home & # 92; (- name a.out -o -name "*. o" &# 92;) - atime +7 -exec rm {} \; < br />find . -atime 0 -print
find / .name .profile -print
find . -perm 777 -a -mtime 7 -exec chmod 755
common command formats of UNIX system:
command [flags] [argument1] [argument2]...
where flags start with - and multiple flags can be connected with one -, for example, LS - L - A is the same as LS - La
according to different commands, parameters can be divided into optional or required ones; All commands are input from the standard input, the output
results are displayed in the standard output, and the error information is displayed in the standard error output device. You can use the redirection function to redirect
these devices
the command returns a value of 0 after the normal execution result. If the command fails to complete completely, it returns a value of
non-zero (variable $? Can be used in shell)? This return value can be used as a part of control logic
in shell script
note: different UNIX versions may have different flags<
1. User related commands
1.1 login
(in Linux RedHat, the function of this command is different from Solaris / BSD, and login will exit the current task).
login:
password:
related files:
set the necessary path and terminal type in the following files, Other variables or special programs.
$home /. Profile (Bourne shell, SH, bash)
$home /. Cshrc (CSH, tcsh)
$home /. Tcshrc (tcsh)
/ etc / passwd file lists the shell of each user
/ etc / CSH. Cshrc
/ etc / CSH. Login
/ etc / profile (Bourne shell, bash)
/ etc / login (Bourne shell, bash)
/ etc / login (Bourne shell, Bash)
CSH: / etc / csh.cshrc and $home /. Cshrc are read every time they are executed,
while / etc / csh.login and $home /. Login are only executed by registered shell.
after modifying the corresponding files, use source.cshrc to enable relevant modifications. If the path is modified,
you need to use rehash to refresh the executable hash table
tcsh: $home /. Tcshrc, no files read. Cshrc
sh: / etc / profile and $home /. Profile register shell
bash: / etc / profile and $home /. Bash_ Profile registered shell read
. Bashrc interactive unregistered shell read
execute related files manually under SH / bash:
. / etc / profile
execution order of related files
sh: / etc / profile - & gt$ HOME/.profile
csh/tcsh: /etc/csh.cshrc -> / etc/csh.login -> $ HOME/.cshrc
-> $ Home /. Login
variable setting:
SH / bash: term = VT100; Export term
or: export term = VT100 (bash)
CSH: setenv term VT100
common variables:
(1) backspace $home /. Profile $home /. Cshrc
stty erase ^ H
(2) umask new file or directory protection attributes
(3) term
(4) avoid adding in path.
1.2. Rlogin
similar to telnet, Connect to the remote host.
rlogin remotehost [- L loginname]
or:
RSH [- L loginname] remotehost [command]
related files:
remote host's / etc / hosts.equiv and $home /. Rhosts
related network configuration files:
/ etc / inetd.conf R system services. In RedHat, shell, login, exec and, The network daemons corresponding to
are in.rshd, in.rlogind, in.rexecd.
suggestion: from the perspective of security, Close R series services.
1.3. Telnet
telnet remotehost [port]
related files:
/ etc / inetd.conf file.
/ etc / issue.net
tips: Strings / usr / SBIN / in. Telnetd | egrep issue
1.4. Passwd change password
1.5 exit exit current shell
2. Search command or file
2 />Related shell variables:
CSH / tcsh: $path
. Cshrc set path = (/ usr / bin / usr / local / bin $path)
SH / bash: $path
. Profile. Bash_ profile
PATH=/usr/local/bin:$PATH; Export path
2.1 which
syntax: which command
which is the built-in command of bash / tcsh
[ hbwork@toshiba ]$which
which: shell build in command.
2.2 where (tcsh)
syntax: where command
2.3 locate (Linux)
syntax: locate file name
related commands: updatedb change locate file name database < B R / >
3. View command usage
man
related files:
/ etc / man. Config
4. Administrator's common command
4.1 install
is used to install a new command or daemon, etc, However, many software use install to the target file to the corresponding directory and set the correct attributes in its installation
shell script.
name
install - files and set their attributes
synopsis
install [options] [- S] [- strip] source dest
install [options] [- S] [- strip] source... Directory
install [options] [- D, - Directory] Directory...
Options:
[- C] [g group] [M mode] [O owner] [group = group]
[- mode = mode] [owner = owner] [help] [version]
4.2 shutdown
different UNIX parameters are different, The following shutdown methods are commonly used in Linux:
shutdown - h now
shutdown - r now (equivalent to boot)
4.3 halt
poweroff
shutdown. It is not recommended in multi-user mode (runlevel 3).
4.4 ulimit
this command can be used in Korn shell and Bourne shell, In CSH series, the corresponding command is limit.
used to limit the system resources that can be used by each process. There are usually two kinds of restrictions:
. For the resources defined by hard limits system, only root can change
, Hard limit that can be added to the system.
flags:
- a lists soft limits
- ha lists hard limit
- C size sets the block size of coremp size
- t size cputime
- f size file size
4.5 umask system administrators use to set the user's default umask value.
5. Process related commands
basic concept of process: process and process Command execution is related, but not one-to-one correspondence; A command may correspond to several
processes (such as shell script, pipe, etc.), but the simplest command and umask have only one process.
process classification:
. Interactive process: can be executed in the foreground or background, and can be switched between the foreground and the background, Generally, they are executed sequentially in the task queue, such as tasks submitted through
at and crontab.
. Deamon: processes that never terminate, waiting to respond to service requests from other processes, such as sendmail,
named (DNS),
, POP3 and Apache, etc.
process related attributes:
PID
Real uid
effective uid (suid)
Real GID
effective GID (sgid)
priority (nice number) execution priority
5.1 ps
process status, which lists the current running process status, according to different options, All or part of the processes can be listed
. If there is no option, only the process (SYSV) started from the current terminal or the process (BSD) of the current user ($user) can be listed, There are differences between different UNIX versions. Linux uses BSD version of ps
. How to use BSD version of PS command:
ps
PS aux lists the details of all processes in the system
PS aux | egrep inetd
output information content:
PID
terminal if there is no corresponding terminal -
CPU time
userid or username
process start time Or date
process status (STAT: s (LEEP) r (unnable) d (uninterrupt sleep) Z (omnie)
W process has no resident page, N: process's nice value is negative
5.2 kill
kill [- signal] PID
kill - L list available semaphores
common information:
- HUP (1) restart process
PS ax | egrep inetd
kill - HUP PID_ of_ Inetd
- kill (9) forced stop
PID value meaning:
& gt; 0 refers to a specific process (actual process)
= 0 all process (PGID) of users in the same group
= - 1 effective uid = uid of user executing command
& lt; 0 && != 1 process with absolute value
5.3 nice
is used to change the priority of one or more processes; But only root or raise the priority of the process, ordinary users can only
lower the priority of the process.
nice uses a negative number to raise the priority, while a positive number to lower the priority. Generally, the value range is - 20 ~ 20.
if the priority is not specified, the process can be upgraded, Nice will rece or not change the priority of the process. Of course, if you do not have permission,
the priority of the process will not change.
generally, we use nice to rece the priority of the background process (the default priority is 10).
nice find. - name & quot; * c" - print &
nice 16 find . -name "*. c" - Print &
5.4 wait
wait PID
the parameter is PID, which is sometimes used in shell script.
5.5 nohup
nohup Command &
5.6 sleep
sleep seconds
switch between front and back stages of process: Ctrl-Z, FG, BG
6. Communication
6.1 FTP
6.2 mailx
6.3 minicom (serial terminal, modem)
7. File comparison
CMP
comm
diff (for comparing text files)
diff3 (for comparing three files)
sdiff
8. File operation
touch to create a file, Modify the file date, etc.
Chmod
chwon
chgrp
RM use RM - RF
MV to move the file or change its name
CP CP - R directory
cat
RCP remote
ln the default is hard connection, Each file has the same inode
ln - s Sourcefile targetfile
9. Directory operation
MKDIR [- P] [M mode] directory
rmdir [- P] directory
10. File information command
LS
find
the most basic function is to find a file name or directory, The common formats are as follows:
find. - Print (similar to LS - LR)
find can use the following attributes to find:
- name to find the file name, including wildcards *? The file name of is enclosed in quotation marks
- perm 00x000 octal file attribute
- atime file accessed n days ago
- Mtime file modified n days ago
- CTime n file status modified n days ago
- exec command if the return code of the command is zero (find the corresponding file), the command must be in the form of
\; As a result, in addition, {} is the path name of the found file ring the execution of the command,
- OK command is similar to exec, but the user is required to confirm that
- print prints the current path name
- new filename. If the last modification date of the file is newer than the filename, it is true
- type C = [b, C, D, l, P, f] File type
- user userif the owner of the file is username, it is true
- nouser file owner does not exist in / etc / passwd file
- group growname file group
logical operator: - A - O
List:
find $home & # 92; (- name a.out -o -name "*. o" &# 92;) - atime +7 -exec rm {} \; < br />find . -atime 0 -print
find / .name .profile -print
find . -perm 777 -a -mtime 7 -exec chmod 755
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