. , Unix (). , . ( ee,ed,red,vi,ex), .
, , . , , . "=". Shell- , , . :
var_1=13 # "13" - , .
var_2=" UNIX" # , .
, "=".
$.
echo $var_1 # $var_1
:
read var_1
,
, $1 $9.
, , { } " ". , Shell :
- $? ;
- $$ - Shell;
- $! - , Shell ;
- $# - , Shell;
- $- - , Shell.
shell . "#". , ( ) , . , , , :
now = `date` ( `` - )
echo $now
Sun Feb 14 12:00:01 PST 1985
shell
Shell, , , if, case, while, until, for, break . , , , test , , , ..
|
|
|
TEST
test . shell. test:
test [ ]
shell test "[", . . .
:
;
;
.
:
N op M, N, M , op :
| -eq -ne | |
| -le | |
| -ge | |
| -lt | |
| -gt | |
:
op filename, op :
| -s | |
| -f | |
| -d | |
| -w | |
| -r |
:
S op R, op :
| = | |
| != |
op R, op :
| -z | |
| -n |
IF
: :
if <> echo -n
then < > read z
[elif <> then < >] if [ $z = 423 ]
[else < >] then echo
fi elif [ $z = 495 ]
then echo
elif [ $z = 815 ]
then echo
else echo
fi
a (and)
- o (or).
CASE
: :
case <> in echo -n
1) < >;; read z
2) < >;; case $z in
3) .. 423) echo ;;
esac 495) echo ;;
815) echo ;;
*) echo ;;
esac
";;", . , ";" .
*. , ( $z) , ")".
FOR
