, , . Shell . . , , , .
shell
dl :
pwd<ENTER>
ls<ENTER>
echo This is the end of the shell program.<ENTER>
shell. cat:
cat dl<ENTER>
shell sh. :
sh dl<ENTER>
chmod :
chmod u+x dl<ENTER>
, chmod (+x) (u). dl . . : dl<ENTER>
dl . , . : PATH (, , shell ) , :
PATH=PATH:.; dl 1
./dl 2
shell
Shell , . , .
Shell . :
;
;
.
shell . , , . , $: $1, $2, $3 .. Shell 9 . shell :
shell.prog pp1 pp2 pp3 pp4 pp5 pp6 pp7 pp8 pp9 <ENTER>
$1 pp1, $2 - pp2 .. . . who , . whoson, , . whoson : who | grep $1 < ENTER >
who , grep , , $1. whoson, , user1.
|
|
|
user1 , grep whoson .
: $?
shell , , . 0 (), . , .
, . . . :
name_variable=value<ENTER>
, , .
var1 - , myname - , :
var1=myname<ENTER>
$ shell . , $var1 shell, $var1 myname.
:
ls2=ls l
$ ls2
. , : echo $variable_name
variable_name. : env shell. env .
. shell , , , . , unset. : unset [ _ ]
