Shell Programming and Scripting

$ umask =rx, u+w                                       
$ print Keep track of everythine > file1.out           
$ print Be careful >> file1.out                        
ksh: file1.out: cannot create [Permission denied]
$ umask -S                                             
u=,g=,o=
$ set -o | tee tee.out | grep ignoreeof                
ignoreeof                off
$ grep monitor < tee.out                               
ksh: tee.out: cannot open [Permission denied]
$ print ~me | grep me | cat >> file1.out         
ksh: file1.out: cannot create [Permission denied]
$ print *.out                                          
file1.out tee.out
$ /usr/bin/grep track *.out | wc                       
grep: can't open file1.out
grep: can't open tee.out
       0       0       0
$ grep track < f*out | wc                              
ksh: file1.out: cannot open [Permission denied]
       0       0       0
$ time sleep 20 > /dev/null 2>&1                       

real    0m20.02s
user    0m0.00s
sys    0m0.00s

umask -S
u=rwx,g=rx,o=rx

umask =  
umask -S
u=,g=,o=