Linux Shell Learning Note 00

1. Bash = Bourne Again SHell

2. Terminal prompt:

#普通用户 [email protected]$ #管理员用户 [email protected]#

3. The shell script is usually a text file that starts with Shebang:

#！ /bin/bash

Shebang is a line of text where #! is before the interpreter path. /bin/bash is the command path of the BASH interpreter.

In Unix jargon, the character "#" is usually read as "sharp" or "hash" or "mesh" to address the exclamation point "!" Called Bang, "shebang" means that the two words match up "#! ”。

4. Write the string to text:

echo "This is a sample text!" > Temp.txt

Insert a string after the text:

echo "This is another sample text!" >> temp.txt

To view the contents of a text file:

Cat Temp.txt

REDIRECT error message stderr to text:

$ ls + 2> OUT.txt

LS + is an error statement, "2>" is a stderr redirect.

/dev/null is a special device file, and any data it receives will be discarded and called a device black hole. Data is gone.

5. Generate the delay in the script:

#！ /bin/bashecho-n count:tput sccount=0;while true;do    If [$count-lt];    then let        count++;        Sleep 1;        Tput RC        tput ed        echo-n $count;    else exit 0;    Fidone

Linux Shell Learning Note 00