1) ps [options] show status of active
processes
ps is used to report on processes currently running on the system.
The output format and valid
options are very specific to the OS and program version in use.
Syntax
ps [options]
2)
script file saves everything that appears on the screen to
file until exit is executed
script creates a script of your session input and output. Using
the script command, you can capture
all the data transmission from and to your terminal screen until
you exit the script program. This can
be useful during the programming-and-debugging process, to
document the combination of things
you have tried, or to get a printed copy of it all for later
perusal.
Syntax
script [-a] [file] <. . .> exit
3)
whereis [options] command report the binary, source, and man
page locations for the command
named
4)
which command reports the path to the command or the shell
alias in use
5)
who or w report who is logged in and what processes are
running
J10BCPNCAP $ who
root console
Apr 26 10:17
tibadmin pts/17
Jun 30 09:37 (10.8.149.62)
oracle pts/18
Jun 27 14:24 (10.8.85.140)
tibadmin pts/19
Jun 30 10:09 (10.8.149.154)
tibadmin pts/21
Jun 30 15:11 (10.8.149.91)
tibadmin pts/26
Jun 30 12:10 (10.8.74.107)
tibadmin pts/27
Jun 30 12:55 (10.8.74.107)
6)
grep
The grep utility is used to search for generalized regular
expressions occurring in Unix files.The egrep utility provides
searching capability using an extended set of meta-characters. The
syntax of the grep utility, some of the available options, and a few
examples are
shown below.
Syntax
grep [options] regexp [file[s]]
Common Options
-i ignore case
-c report only a count of the number of lines containing matches,
not the
matches themselves
-v invert the search, displaying only lines that do not match
-n display the line number along with the line on which a match
was found
-s work silently, reporting only the final status:
0, for match(es) found
1, for no matches
2, for errors
-l list filenames, but not lines, in which matches were found
7)
whoami
J10BCPNCAP $ whoami
tibadmin
8)
who am i
J10BCPNCAP $ who am i
tibadmin pts/21
Jun 30 15:11 (10.8.149.91)
9)
id
The purpose of
this command is to tell you what group or groups you’re in and
the numeric identifier for your account name (known as your user ID
number or user ID). Enter id and see what you get. I get the
following result:
%
id
uid=211(taylor) gid=50(users0) groups=50(users0)
%
J10BCPNCAP $ id
uid=1005(tibadmin) gid=1(other)
10)
users-which lists the account names of all people using the
system:
J10BCPNCAP $ users
root tibadmin oracle tibadmin tibadmin tibadmin tibadmin
11)
w
w is a complex command which summarizes information
This is a much more complex command, offering more information
than either users or who. Notice that the output is broken into
different areas. The first line summarizes the status of the system
and, rather cryptically, the number of programs that the computer is
running at one time. Finally, for each user, the output indicates the
user name, the tty, when the user logged in to the system, how long
it’s been since the user has done anything (in minutes and
seconds), the combined CPU time of all jobs the user has run, and the
amount of CPU time taken by the
current job. The last field tells you what you wanted to know in
the first place: what are the users doing?
3:18pm up 65 day(s), 11:12, 7 users, load
average: 1.39, 1.42, 1.43
User tty
login@ idle JCPU PCPU what
root console
26Apr1165days
-sh
tibadmin pts/17 9:37am
5:40 1 1
tail -100f SUBSCRIPTION_DTH-Proc
oracle pts/18 Mon
2pm 3days
oracleSDP (DESCRIPTION=(LOCAL=YE
tibadmin pts/19 10:09am
5:09 1 1
tail -f SUBSCRIPTION_DTH-Process
tibadmin pts/21
3:11pm
w
tibadmin pts/26 12:10pm
3:07
-sh
tibadmin pts/27 12:55pm
2:22
less ICCM_BW-ICCM_BW.log
12)
cal
shows a simple calendar for the month or year specified.
eg:
$ cal
June 2011
S M Tu W Th F S
1 2
3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30
For a particular month cal [ [month] year ]
$ cal 3 1988
March 1988
S M Tu W Th F S
1 2 3 4
5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31
cal 2007
2007
Jan
Feb
Mar
S M Tu W Th F S S
M Tu W Th F S S M Tu
W Th F S
1 2 3 4 5
6
1 2 3
1 2 3
7 8 9 10 11 12 13 4 5
6 7 8 9 10 4 5 6
7 8 9 10
14 15 16 17 18 19 20 11 12 13 14 15 16 17
11 12 13 14 15 16 17
21 22 23 24 25 26 27 18 19 20 21 22 23 24
18 19 20 21 22 23 24
28 29 30 31
25 26 27 28
25 26 27 28 29 30 31
Apr
May
Jun
S M Tu W Th F S S
M Tu W Th F S S M Tu
W Th F S
1 2 3 4 5 6 7
1 2 3 4 5
1 2
8 9 10 11 12 13 14 6 7
8 9 10 11 12 3 4 5 6
7 8 9
15 16 17 18 19 20 21 13 14 15 16 17 18 19
10 11 12 13 14 15 16
22 23 24 25 26 27 28 20 21 22 23 24 25 26
17 18 19 20 21 22 23
29 30
27 28 29 30 31 24 25
26 27 28 29 30
Jul
Aug
Sep
S M Tu W Th F S S
M Tu W Th F S S M Tu
W Th F S
1 2 3 4 5 6
7
1 2 3 4
1
8 9 10 11 12 13 14 5 6
7 8 9 10 11 2 3 4 5
6 7 8
15 16 17 18 19 20 21 12 13 14 15 16 17 18
9 10 11 12 13 14 15
22 23 24 25 26 27 28 19 20 21 22 23 24 25
16 17 18 19 20 21 22
29 30 31
26 27 28 29 30 31 23 24 25 26 27 28 29
30
Oct
Nov
Dec
S M Tu W Th F S S
M Tu W Th F S S M Tu
W Th F S
1 2 3 4 5
6
1 2 3
1
7 8 9 10 11 12 13 4 5
6 7 8 9 10 2 3 4
5 6 7 8
14 15 16 17 18 19 20 11 12 13 14 15 16 17
9 10 11 12 13 14 15
21 22 23 24 25 26 27 18 19 20 21 22 23 24
16 17 18 19 20 21 22
28 29 30 31
25 26 27 28 29 30 23 24 25 26 27 28 29
30 31
13)
bc
The bc utility implements an arbitrary precision calculator.It
takes input from any files given, then reads from
the standard input.
J10BCPNCAP $ bc
4*2
8
5-8
-3
6+9
15
sqrt(25)
5
14)
dcThe dc command works with the postfix notation, and each number or
operation must be on its own line. Further, the result of an
operation isn’t
automatically shown; you have to enter p to see the most recently
calculated result.
J10BCPNCAP $ dc
9
9
*
p
81