Calendar
The cal command to see the calculator of any specific month or a complete year.
Syntax: cal [[ month ] year ]
ex: cal 03 2016
cal 2016 | more
ECHO:
echo is one of the most commonly and widely used built-in command for Linux bash and C shells, that typically used in scripting language and batch files to display a line of text/string on standard output or a file.
Syntax: echo [OPTION]... [STRING]...
Example: echo "hello" output: helloSyntax:
ex: echo -e "Tecmint \bis \ba \bcommunity \bof \bLinux \bNerds"
TecmintisacommunityofLinuxNerds
echo -e "Tecmint \nis \na \ncommunity \nof \nLinux \nNerds"
Tecmint
is
a
community
of
Linux
Nerds uxNerds
Echo the STRING(s) to standard output.
| Tag | Description |
|---|---|
| -n | do not output the trailing newline |
| -e | enable interpretation of backslash escapes |
| -E | disable interpretation of backslash escapes (default) |
| --help | display this help and exit |
| --version | |
| output version information and exit | |
| If -e is in effect, the following sequences are recognized: | |
| \0NNN | the character whose ASCII code is NNN (octal) |
| \\ | backslash |
| \a | alert (BEL) |
| \b | backspace |
| \c | suppress trailing newline |
| \f | form feed |
| \n | new line |
| \r | carriage return |
| \t | horizontal tab |
| \v | vertical tab |
Printf:
Display text in formatted
%s String
%30s print space in a 30 characters wide
%d decimal
%o octal
%x Hexadecimal
%f Floating point number
Example
$ printf "%s\n" "hello printf" "in" "bash script"
hello printf
in
bash script
bc - Unix calculator
bc is a unix command which stands for bench calcultor. Depending on the way we use it, it can either look like a programming language or as a interactive mathematic shell. Let us see in this article how to use bc to do some simple arithmetic.
bc
bc 1.06
Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
100+500
600
1000/3
333
passwd ---- Assigning password
passwd username
who are the users
w ---- to know who are the users connected
who am i
Uname: features of operating system.
uname -a ----- all the details
uname -r ---- kernel version
DATE : Displaying the System Date
you can display the current date with date command, which shows the date and time to nearest second.
Syntax: date
Fri Jan 22 17:39:08 IST 2016
Format:
date '+DATE: %m/%d/%y%nTIME:%H:%M:%S'
output:
DATE: 01/22/16
TIME:17:54:15
DESCRIPTION
Display the current time in the given FORMAT, or set the system date.
-d, --date=STRING display time described by STRING, not `now'
-f, --file=DATEFILE like --date once for each line of DATEFILE
-r, --reference=FILE display the last modification time of FILE
-R, --rfc-2822 output date and time in RFC 2822 format. Example: Mon, 07 Aug 2006 12:34:56 -0600
--rfc-3339=TIMESPEC output date and time in RFC 3339 format. TIMESPEC=`date', `seconds', or `ns' for date and time to the indicated precision. Date and time components are separated by a single space: 2006-08-07 12:34:56-06:00
-s, --set=STRING set time described by STRING
-u, --utc, --universal print or set Coordinated Universal Time
--help display this help and exit
--version output version information and exit
FORMAT controls the output. Interpreted sequences are:
%% a literal %
%a locale's abbreviated weekday name (e.g., Sun)
%A locale's full weekday name (e.g., Sunday)
%b locale's abbreviated month name (e.g., Jan)
%B locale's full month name (e.g., January)
%c locale's date and time (e.g., Thu Mar 3 23:05:25 2005)
%C century; like %Y, except omit last two digits (e.g., 20)
%d day of month (e.g., 01)
%D date; same as %m/%d/%y
%e day of month, space padded; same as %_d
%F full date; same as %Y-%m-%d
%g last two digits of year of ISO week number (see %G)
%G year of ISO week number (see %V); normally useful only with %V
%h same as %b
%H hour (00..23)
%I hour (01..12)
%j day of year (001..366)
%k hour, space padded ( 0..23); same as %_H
%l hour, space padded ( 1..12); same as %_I
%m month (01..12)
%M minute (00..59)
%n a newline
%N nanoseconds (000000000..999999999)
%p locale's equivalent of either AM or PM; blank if not known
%P like %p, but lower case
%r locale's 12-hour clock time (e.g., 11:11:04 PM)
%R 24-hour hour and minute; same as %H:%M
%s seconds since 1970-01-01 00:00:00 UTC
%S second (00..60)
%t a tab
%T time; same as %H:%M:%S
%u day of week (1..7); 1 is Monday
%U week number of year, with Sunday as first day of week (00..53)
%V ISO week number, with Monday as first day of week (01..53)
%w day of week (0..6); 0 is Sunday
%W week number of year, with Monday as first day of week (00..53)
%x locale's date representation (e.g., 12/31/99)
%X locale's time representation (e.g., 23:13:48)
%y last two digits of year (00..99)
%Y year
%z +hhmm numeric time zone (e.g., -0400)
%:z +hh:mm numeric time zone (e.g., -04:00)
%::z +hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::z numeric time zone with : to necessary precision (e.g., -04, +05:30)
%Z alphabetic time zone abbreviation (e.g., EDT)
By default, date pads numeric fields with zeroes. The following optional flags may follow `%':
- (hyphen) do not pad the field
_ (underscore) pad with spaces
0 (zero) pad with zeros
^ use upper case if possible
# use opposite case if possible
Examples:
date +%m ---- display month in numeric
date +"%h %m"
[root@rhel6 ~]# date +%a
Sat
[root@rhel6 ~]# date +%A
Saturday
[rootrhel6 ~]# date +%M
31
[root@rhel6 ~]# date +%m
12
[root@rhel6 ~]# date +%a
Sat
[root@rhel6 ~]# date +%A
Saturday
[root@rhel6 ~]# date +%B
December
[root@rhel6 ~]# date +%b
Dec
[root@rhel6 ~]# date
Sat Dec 19 00:32:14 IST 2015
[root@rhel6 ~]#
d ----- the day of the month ( 1-31)
y ----- the last two digits
H,M and S hour , min and sec
D ---- The date in format dd/mm/yy
T ----- Time hh:mm:ss
No comments:
Post a Comment