1.1 Shell Features

#shell特性

| Pipeline

> Redirection

>> Chasing heavier orientation

< reverse redirection

2> Error Redirection

2>> Append Error redirection

#作业控制

CTRL + Z to temporarily stop the job

Jobs View Job

FG recalled to front desk

+ Higher Priority

FG 2 designated number recall

BG tuned to Backstage

Sleep & also executes the command and adds & recalls the background.

Exercises:

1. What are the functions of the following special symbols?

!! You can execute the previous command

!ca can execute the last command in the command history that starts with a CA

!100 can execute 100th command in command history

!$ means the last parameter of the previous command

2. The argument about redirection is correct.

> redirect for correct output if there is content in the target file it overwrites the old content

2> is the wrong redirect, only the wrong information is logged

2>>1.txt error message appended to 1.txt

3. What do I do if I want to put the command "sh 1.sh" into the background?

SH 1.sh, then CTRL + Z, then BG ID

SH 1.sh &

Summarize

Main: Job Control

1.1 Shell Features