learn shell(updating....)

Created2022-05-02Updated2022-05-04

# First-Shell-Script

echo "hello world" # Anyway, you can writing another string , like `echo "fuck shell"`

In Linux , create new file test.sh , using vim to edit test.sh , coding first shell script. And use chmod +x test.sh give run permissions.

Then, run ./test.sh , like this:

# Shell-Variable

You can create variable in shell, example:

	variable_str="variable"
	variable_int=123
	variable_float=1.2
	echo -e "str:${variable_str} \n int:${variable_int} \n float:${variable_float}"
	# if you want to use escape character, like `\n`、`\t` and so on , you should use `echo -e` to print it,
	# if not, the string '\n' is printed instead of a newline character .

run ./test.sh , like this:

# String

	string="fuck shell"
	echo $string

# Intercept-String

You can use string slice to extract the substring , example:

	string="fuck shell"
	echo ${string:2:4}