Detailed explanation of common command lines for iOS development

For iOS development, we don’t use many command lines, but there are still some that we need to be familiar with. Recently, I worked with some experts in the company on some things, and there were all kinds of command lines. I was embarrassed that I didn’t know how to use them. In fact, I didn’t know what command lines were. For example, the simplest command of how to check the IP address using the terminal, I even forgot what the command was. So today I am going to learn some common command lines to save myself from embarrassment in the future??

[[218189]]

man

When we use some programs, we may not know what commands they have. At this time, we can use the man command.

Get help for ls

 $ man ls

See how many manuals (for different aspects) have the same name

 $ man -f ls
 ls (1) - list directory contents
 ls (1p) - list directory contents

View specific manual

      
 $ man 1p ls

Exit man

 After execution, press q to exit in the man page.

help

You can tell what help means just by looking at the name. Generally, programs will have this parameter, which will output the simplest and most useful introduction.

 $ man --help ### Get help from man  
 $ ls --help ### Get help for ls  

cursor

 Up (up arrow key) can call up the input history execution record and quickly execute commands
 down (down arrow key) with up to select historical execution records
 Home Move the cursor to the beginning of the line
 End Move the cursor to the end of this line
 PgUp Page up
 PaDN Page down

There are no Home, End, Page UP, Page DOWN keys on the keyboard of Apple Mac computers. You can get the same functions by using the Fn key combination: Home key = Fn + left direction, End key = Fn + right direction, Page UP = Fn + up direction, Page DOWN = Fn + down direction

Terminate the current program

 1ctrl + c terminates the current program

Tab completion

Tab completion is a very useful feature that can be used to automatically complete commands or file names.

• Press Tab twice without input to list all available commands.
• A partial command name or file name has been entered. Press Tab to complete it automatically.

After I enter De, I press the Tab key to complete Desktop/, and then press the Tab key twice in succession to view all the directories under Desktop/

cd

cd is to find the file according to the path

For example, there is a Text file on the desktop

• Absolute path: The absolute path emphasizes starting from / and continuing to the path cd Desktop/Text
• Relative path: directly cd Text
• . represents the current directory; .. represents the parent directory; the parent directory can be accessed by cd ..

ls

 $ ls ### List only visible files in the current directory
 $ ls -l ### List the detailed information of the visible files in the current directory
 $ ls -hl ### List detailed information and display file sizes in readable sizes
 $ ls -al ### List detailed information of all files (including hidden files)

more

Generally, when a document is too long, we cannot display it completely on one screen. In this case, we need to use the more command. More displays the content line by line.

less

Less is similar to more, but less supports scrolling up and down to view the content, while more only supports line-by-line display.

Restart Command

reboot is the reboot command

 # reboot
 The difference between '$' and '#' is that '$' can be executed by ordinary users.
 The '#' command is executable only by the root user, or by ordinary users using 'sudo'.  

Shutdown Command

 poweroff is the shutdown command
 poweroff Shut down immediately

ping

Ping is mainly used to test network connectivity. It sends data packets to the target machine to test whether the two hosts are connected and the delay. Ping is done through the domain name. If the DNS is not set up properly, ping may not be successful.

Get network parameters

The ifconfig command is used to configure and display the network parameters of the network interface in the Linux kernel. The network card information configured with the ifconfig command will not exist after the network card is restarted and the machine is restarted. If you want to store the above configuration information permanently in the computer, you need to modify the network card configuration file.