test -b FILE
test -c FILE
test -e FILE
test -f FILE
test -h FILE
test -l FILE
test -p FILE
test -r FILE
test -w FILE
test -x FILE
test INTEGER1 -eq INTEGER2
test INTEGER1 -ge INTEGER2
test INTEGER1 -gt INTEGER2
test INTEGER1 -le INTEGER2
test INTEGER1 -lt INTEGER2
test INTEGER1 -ne INTEGER2
cd
Change the shell working directory
cdcd /home/usr
umask
set or display file mode
umaskumask 0666
time
display the system time
time
env environ
display all the environment variables
env OR environ
clear clr
clear the terminal screen
clear OR clr
set
set the environment variables
set VAR
set VAR VALUE
unset
unset the environment variables
unset VAR
exec
replaces the shell with specified command
exec ls
help
display the README doc
help
exit
cause normal process termination
exit
continue
return the value of $? to 10
continue
shift
move popositional parameters
shift OR shift n
$
get the environment variables or get the argument
$HOME$PATH$1$?
myshell batchfile
Processes a batch file that contains a set of commands