⌨️ Bash scripting

$ bash --version

Common bash commands:

$ ls - List directory contents
$ echo - Prints text to the terminal windows
$ touch - Creates a file
$ mkdir - Create a directory
$ pwd - Print working directory
$ cd - Change directory
$ mv - Move or rename directory
$ less -  View the contents of a text file (no edit)
$ cat - Read a file, create a file and concatenate files
$ chmod - Sets the file permissions flag on a file or folder
$ exit - Closes terminal, log you out of remote SSH access session, end execution of a shell script
$ history - List your most recent commands
$ clear - Clear your terminal window
$ cp - Copy files and directories
$ kill - Terminate stalled processes

Første script:

$ nano hello.sh
#!/bin/bash
echo "Hello World"
$ bash hello.sh
Hello World

Brug af comment:

$ nano comment.sh
#!/bin/bash

Add two numeric values:

((sum=25+35))

#Print the result
echo $sum
$ bash comment.sh
60

While loop:

$ nano while.sh
#!/bin/bash
valid=true
count=1
while [ $valid ]
do
echo $count
if [ $count -eq 5 ];
then
break
fi
((count++))
done
$ bash while.sh
1
2
3
4
5

For loop:

$ nano for.sh
#!/bin/bash
for (( counter=10; counter>0; counter-- ))
do
echo -n "$counter "
done
printf "\n"
$ bash for.sh
10 9 8 7 6 5 4 3 2 1

Get User Input:
$ nano user_input.sh
#!/bin/bash
echo "Enter Your Name"
read name
echo "Welcome $name to bash scripting"
$ bash user_input.sh
Enter Your Name
Mads
Welcome Mads to bash scripting

If statement:

$ nano simple_if.sh
#!/bin/bash
n=10
if [ $n -lt 10 ];
then
echo "It is an one digit number"
else
echo "It is a two digit number"
fi
$ bash simple_if.sh
It is a two digit number