Linux Tutorial 1
Lots of basic stuff here.
Basic Commands:
echo ## Will output file text
whoami ## Will output username
File system
cd ## Change directory
ls ## list files in direcotry
cat ## show contents of the file
pwd ## Print Working Directory
For example, change to directory cd, then list files ls and show the contents of a file cat
Searching for files
Commands to search for files
find ## search for files
grep ## text search within files
Example - if we know that name of the file that we are looking for is passwords.txt
find -name passwords.txt
Example - name of file ends with “.txt”
find -name *.txt
Example - want to find a specific line in a file. Can’t use cat here. We are searchfor the IP add ress “81.143.211.90”.
grep "81.143.211.90" access.log
Example - find the prefix “THM” in access.log
grep "THM" access.log
Shell operators
”&” sign will run a command in the background so we can go on and do other things.
”&&” has literally nothing to do with ”&“. ”&&” allows us to make a list of commands to run. command1 && command2.
However, the second command will only run if the first one was successful.
”>” is an output redirect. It will take the output of the command and send it somwhere else. An example would be taking the output of a command and saving it to a file for later
echo hey > welcome.txt # output "hey" to "welcome"
Note that Linux doesn’t really care about filenames. “welcome” is just as valid as “welcome.txt”
”>>” Like ”>” except that this will append to the file instead of overwriting the values.
echo hello > welcome # will add "hello" to "welcome" file