 28.1.   test
         ,   

-d                  

-               

-f                  

-                   

-s                   

-w                   

-                  

^^^k      .       , 
^^^^     ,    
^     .      
^^           .  
  ,      .

     chkargs    ,
       Linux.    
 test       ([]).  -
    test     test  
,    .      -
  (  TAB).

$ cat chkargs2

if [ $# -eq 0 ]
then

echo ": chkargs2 ..." 1>&2

exit 1
fi

echo " ."
exit 0
$ chkargs2

: chkargs2 
$ chkargs2 abc
 .

  ,   chkargs2,   
 (usage message)    1>&2   
    (.  "  " -
 9).      chkargs2   
  1,   .  exit 0   -
    chkargs2   0   
.

         -
 ,  .   Linux   
,  chkargs2.        -
         .

870                                                  VI. 