linux commands in shell

cat ./../mainfile.php - Config file.

ls -la - Lists directory's.

ifconfig {eth0 etc} - Ipconfig equiv.

ps aux - Show running proccess's.

gcc in_file -o out_file - Compile c file.

cat /etc/passwd - List's accounts.

sudo - Superuser Do run a command as root provided you have perms
in /etc/sudoers.

id - Tells you what user your logged in as.

which wget curl w3m lynx - Check's to see what downloaders are
present.

uname -r - Shows all release info (or) cat /etc/release.

uname -a - shows all kernal info (or) cat /etc/issue

last -30 - Last logged 30 ip's can change to desired number.

useradd - Create new user account.

usermod - Modify user account.

w - See who is currently logged on.

locate password.txt - Locates password.txt in current dur can use *.

rm -rf / - Please be carefull with this command, i cannot stress this
enough.

arp -a - Lists other machines are on the same subnet.

lsattr -va - ls file attributes on linux second extended file system

find / -type f -perm -04000 -ls - Finds suid files.

find . -type f -perm -04000 -ls - Finds suid files in current dir.

find / -type f -perm -02000 -ls - Finds all sgid files.

find / -perm -2 -ls - Finds all writable files and folders.

find . -perm -2 -ls - Finds all writable files and folders in current dir.

find / -type f -name .bash_history - Finds bash history.

netstat -an | grep -i listen - shows open ports.

cut -d: -f1,2,3 /etc/passwd | grep :: - From memory creates a user
with no pass.

find /etc/ -type f -perm -o+w 2> /dev/null - Write in /etc/passwd?.

cat /proc/version /proc/cpuinfo - Cpu info.

locate gcc- Finds gcc if installed.

set - Display system variables.
echo $path- Echo current path.

lsmod- Dumps kernal modules.

mount/df- Check mounted file system.

rpm -qa- Check patch level for RedHat 7.0.

dmesg- Check hardware ino.

cat /etc/syslog.conf - Log file.

uptime - Uptime check.

cat /proc/meminfo - Memory check.

find / -type f -perm -4 -print 2> /dev/null- Find readble files.

find / -type f -perm -2 -print 2> /dev/null - Find writable files.

chmod ### $folder - Chmod folder.

ls -l -b - Verbosly list directory's

Credit : dodolenak