, .
:
- The Bourne Shell - /bin/sh
- The Bourne again shell - /bin/bash
- The Korne shell - /bin/ksh
- The C shell - /bin/csh
- Tom’s C shell - /bin/tcsh
bash. .
:
cat
;cd
;ls
;echo
;touch
- , ;file
;whatis
;history
;env
;pwd
;export
;unset
- ;
, . bash, . . , , . , , , . -. , /etc/passwd/

, , Jenkins /bin/bash/
. Ubuntu . . . , /etc/profile
.

, , . , PS1 , , -.
, , , . , , , , , . bash.
, .profile . , . ls a
.
, cat .profile

~/.bashrc. .
cat .bashrc.

, , , -. , , , .. . .
, , .
. echo . : echo hello hello. .. , , . , .
, , echo hello; ls
. hello, .
, - .. . echo.
storm. . , - . cat, . , , , cat> storm. , storm, echo . ctrl+c . , storm , , . storm chmod +x storm
. , ls , . , , , , - , , . .
, . env.

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
, . , , .. . , . , , pwd, . /root. /root/storm

. , , . /root/storm
.
ls a.

"." , "." ".." .
- . .. cd . , . cd .. .
, /root, root, ~. , , .
./storm
, "." . .
. , ABC = 123, .. ABC 123. , . export. export ABC
.

, . , , - . , echo $ABC
, "$" , . 123.
, unset ABC. env , ABC .
PATH.
"PATH=$PATH:." , .. $PATH , env . , , . , pwd.
:
touch
.

, txt, ls *.txt
. .. . , , , ls *.t*

, . .
. , ls [1-4].txt
, 4 .
. . , touch {6,7,8}.txt 3 , 6.txt, 7.txt, 8.txt.
, .
uname .

, , Linux. a, Linux jenkins 5.4.0-45-generic #49-Ubuntu SMP Wed Aug 26 13:38:52 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux. , , .
File storm.

, - . whatis .
history - . , - , . , .
, , , , .
, , man, .