Shell Script Learning (i)

Shell Script Learning (i)

A) Introduction to code-style shell scripts

　　　　1. Download Xshell 5

　　　　　　

Build a folder Mkdri Home/data;

1) Look at a 1.sh built in data

　　　　See if the build was successful.

2) and edit echo Hello Word, and save the launch

　　　　　　

　　　　

　　　　3) No permissions were found when running the script. Add permissions.

　　　　

"' Green executable script

　　　　

　　

　　　　II) shell script commands

　　　　1> Download Everedit Editor, other editors can also

After installation

2> variables:

1. When no that variable is the result value is empty, the value of ${name} parentheses can be added without

2.readonly system, non-reproducible, final in ==java

　　　　　　　　　　

　　　　　　3) Delete variable cannot be used

　　　　　　　　　　

• • 1) local variable local variables are defined in a script or command, only valid in the current shell instance, and other shell-initiated programs cannot access local variables.
  • 2) Environment variables All programs, including shell-initiated programs, can access environment variables, and some programs require environment variables to keep them running properly. Shell scripts can also define environment variables when necessary.
  • 3) shell variables shell variables are special variables that are set by the shell program. Some of the shell variables are environment variables, some of which are local variables that guarantee the shell's normal operation.

　　　　　　4) The difference between "and" "

　

　　　　5) Intercept string length

　　　　　　　　　　

　　　　　6) Find the location of the string (only the first one can be found, the duplicates cannot be found)

　　　

　　　　　　7) array

　8) for Loop

　　　　　　　　　　

　　　　Operation

9) Add

　　　　　　　　　　　

10) Subtraction Yu

　　　　　　　　

One) if Then

　　　　　　　　　　　　　　

12) Relational operators

　　　　　　

13) Logical operators

　　　　　　　　

14)

　　　　　　　　　　

　　

Shell Script Learning (i)