I'm writting my note about the bash command here
Learn Bash Scripting by Building Five Programs From freeCodeCamp
echo hello world => Show hello world to the console
echo text >> filename => Write inside a file
pwd => print working directory (print the tree)
ls => show the elements inside the folder
ls <flag> => show the elements in a different way
ls -l => show the elements inside the folder by long list format
ls -a || ls --all => show all the files inside the folder
cd directoryName => change directory
cd .. => go one directory back
cd ../.. => go 2 directory back
more fileName => see the elements inside the file
clear => clear the terminal
mkdir <folder name> => make directory === create a new folder
touch <file name> => create a file => dont forget the extension
command --help => show the help for the command to see more about what can do the command
cp <file> <destination> => copy the file to an other folder
cp -R, -r, --recursive <folder name> => copy the folder and everything inside
rm <file> => remove the file
mv <filename> <new_filename> => change the file name
mv <filename> destination => we can also use mv to move a file
find => used to view the file tree of the website folder to see all the files and folders withing it
find <folder name> => same but can select a folder
find -name <file name> => look for a filde path
mv <file name> .. => to move to the upper folder
rmdir <folder name> => remove a directory/folder
rm -r <folder name> => remove the folder and all the content inside it . Attention, we can't reverse it !!!
exit => exit terminal
sed -i 'nd' <filename> => Delete the n line from a file ex: sed -i '1d' questionnaire.sh
sed -i '$d' <filename> => Delete the last line from a file ex: sed '$d' questionnaire.sh
sed '7,9d' <filename> => Delete line 7 to 9 from a file
VARIABLE_NAME=VALUE => create a variable with a value. If you need to add a space, you need to add double quote
sh=> stand for shell. Use this extension to write shell script
sh questionnaire.sh => use this to run the file questionnaire.sh
bash questionnaire.sh=> same as above, it run the file questionnaire.sh
which bash=> find where the bash is located, this is the absolute path to the bash interpreter
#!<path_to_interpreter>=> add a shebang to tell the program to use a certain bash ex: if response to where bash == /usr/bin/bash the shebang will be #!/bin/bash
./<filename>=> if there is a shebang at the first line, we can run the file directly
-rw-r--r-- => if while doing ls -l we get this, this describe the permissions that differents users have. r => read, w => write, x => execute
chmod +x questionnaire.sh=> give everyone permission to execute script questionnaire.sh