One: echo usage
echo -n -e -n do not wrap --e escape
\a issue a warning sound; \t insert tab; \n newline;
(1) Output hello world without line break
(2) Insert two tabs before the output and hello word
(3) Output two blank lines
(4) Write a fruit store script, the output is as follows:
Elevate file permissions:
execute script
Another way to execute the script
Two: read usage
read -p -t -s -p print output used with input
- Write a script for login account and password, the output is as follows:
Enter: vim login.sh
Three: Use expr, let, (( )) to demonstrate addition, subtraction, multiplication, division, and remainder
Let needs to be called out with a variable
Four:
Redirection usage < , > , >> <input redirection > output redirection, overwrite the previous content >> append, continue to add the previous content
Use, create a test.txt, enter the content
(1) Output the hello world coverage to test.txt
(2) Append hello world to test.txt
(3) Redirect the test.txt file to the wc command
(4) Write a shell script to complete the disk partition, and use redirection to append the input fdisk /dev/sdb <<EOF...EOF
if1 , if conditional statement usage
(1) Compare strings with if
(2) Use if to compare integer sizes
(3) Use if to determine whether the file exists
(4) if condition is empty is false, non-empty is true
Enter vim if.sh
(5) Write an elif.sh script, enter the value of a number and compare the size with 10 -le is less than -gt is greater than
Input: vim elif.sh
2 , case usage
Write a case.sh script, when the input and output parameters are 1, output Monday; when the parameter is 2, output Tuesday; otherwise, output nothing
Input: vim case.sh
3 , for usage
(1) Write a for.sh script and compare the usage of $* and $@
$* This variable represents all the parameters in the command line, $* is to treat all the parameters as a whole
$@ This variable also represents all the parameters in the command line, but $@ treats all parameters separately
$# This variable represents the number of all parameters in the entire command line
Input: vim for.sh
(2) Write a for1.sh script, input n from the command line, and calculate the sum of 1+2+...+n
Input: vim for1.sh
5. Custom function usage
Write a fashion.sh script, define the summation function getSum of two input parameters, and implement the function call
Enter: vim fashion.sh
