Command Function
: Returns 0 or true
. Executes a shell script
bg Puts a job in the background
break Exits the current loop
cd Changes directory
continue Resumes the current loop
echo Displays the command arguments
eval Evaluates the following expression
exec Executes the following command without creating a new process,
replacing the current process
exit Quits the shell
export Makes a variable or function available to other programs that are
executed from this shell
fg Brings a job to the foreground
getopts Parses arguments to the shell script
jobs Lists background (bg) jobs
pwd Displays the current directory
read Reads a line from standard input
readonly Declares as variable as read-only
set Lists all variables
shift Moves the script's input parameters to the left, dropping the first parameter
test Evaluates arguments
[[ Performs a conditional test
times Prints the user and system times
trap Traps a signal so the script can handle
type Displays how each argument would be interpreted as a command
umask Changes the default permissions for a new file
unset Deletes values from a variable or function
wait Waits for a background process to complete