echo $SHELL = prints the default shell name
echo $OSTYPE = prints the operating system name
echo ‘text’ = prints what is held in the quotes
echo $HOME = prints home directory
echo $USER = who is currently using the system
echo $HISTFILE = location of history file
echo $HISTFILESIZE = history’s set size
echo $HISTSIZE = history’s set size
echo “test” | mail -v -s test xyz@abc.com = sending e-mail from a terminal
MAN command
man -f php = info about php modules
man -k php = info about php modules
man php = php manual pages
man man = info about manual pages and their format
man 3 php = shows entries for php in 3rd section of the manual
man php | grep word = searches for a particular word in php manual
man hier = info about directories
man -k php = info about php modules
man php = php manual pages
man man = info about manual pages and their format
man 3 php = shows entries for php in 3rd section of the manual
man php | grep word = searches for a particular word in php manual
man hier = info about directories
LSPCI command
lspci = info about pci devices/ports
lspci | grep VGA = graphics card info
lspci | grep audio = audio card info
lspci | grep -i modem = modem info
lspci | grep -i usb = usb ports info
lspci | grep -i ethernet = ethernet card info
lspci | grep VGA = graphics card info
lspci | grep audio = audio card info
lspci | grep -i modem = modem info
lspci | grep -i usb = usb ports info
lspci | grep -i ethernet = ethernet card info
LS command
ls /var/www/html/*.html = lists all html files
ls .??* = lists all directory names that start with a dot .
ls /etc/rc.d = prints all directories for all available run levels
ls /etc/rc.d/init.d = list of system services’ scripts
ls -l = lists files and folders in the current directory
ls -la = lists files and folders in the current directory with a dot
ls li = files with their inodes
ls -lt = files recently modified
ls -lu = lists files by their accss time
ls -ln = user names and groups numerically displayed
ls -lh = human readable file sizes
ls -lR = displays all the files and their folders
ls -F = lists files by type
ls -c = lists files columnwise
ls –color =always = shows filenames in colors
ls .??* = lists all directory names that start with a dot .
ls /etc/rc.d = prints all directories for all available run levels
ls /etc/rc.d/init.d = list of system services’ scripts
ls -l = lists files and folders in the current directory
ls -la = lists files and folders in the current directory with a dot
ls li = files with their inodes
ls -lt = files recently modified
ls -lu = lists files by their accss time
ls -ln = user names and groups numerically displayed
ls -lh = human readable file sizes
ls -lR = displays all the files and their folders
ls -F = lists files by type
ls -c = lists files columnwise
ls –color =always = shows filenames in colors
ls -l /var/lib/rpm = rpm database
ls = lists contents of a directory
ls . = lists contents of a directory
ls .. = lists contents of a directory
ls / = lists all system directories
ls = lists directories in current directory
ls /var = lists all subdirectories under the /var directory
ls /proc | wc -l = number of subdirectories in /proc directory
ls -ltr =
ls -l filename.ext = checks permissions for a file
ls -l /etc = permission status of all subdirectories
ls -a = shows hidden . Dot directories. A kind of special configuration files not be messed with
LOCATE command
locate xyz = locates file xyz case-sensitive
locate -i xyz = locates file xyz not case-sensitive
locate -r /ls$ = locates files ending in /ls
locate -r james*bond = locate files with james and bond in their names
locate -r ^ boot/grub/me = locate files beginning with boot/grub/me
locate *.jpg > Desktop/myjpgs.txt = stores results of search in a file named myjpgs.txt
locate -i xyz = locates file xyz not case-sensitive
locate -r /ls$ = locates files ending in /ls
locate -r james*bond = locate files with james and bond in their names
locate -r ^ boot/grub/me = locate files beginning with boot/grub/me
locate *.jpg > Desktop/myjpgs.txt = stores results of search in a file named myjpgs.txt