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This is longer than others on here. The reason for this is I have combined two different matrix commands so it would work on all computers. I logged onto my server through a computer and it worked fine. I logged into my server through a mac and it looked $4!t so I have made one that works through both.
Echoes text horizontally centralized based on screen width
Run the alias command, then issue
ps aux | tail
and resize your terminal window (putty/console/hyperterm/xterm/etc) then issue the same command and you'll understand.
${LINES:-`tput lines 2>/dev/null||echo -n 12`}
Insructs the shell that if LINES is not set or null to use the output from `tput lines` ( ncurses based terminal access ) to get the number of lines in your terminal. But furthermore, in case that doesn't work either, it will default to using the default of 80.
The default for TAIL is to output the last 10 lines, this alias changes the default to output the last x lines instead, where x is the number of lines currently displayed on your terminal - 7. The -7 is there so that the top line displayed is the command you ran that used TAIL, ie the prompt.
Depending on whether your PS1 and/or PROMPT_COMMAND output more than 1 line (mine is 3) you will want to increase from -2. So with my prompt being the following, I need -7, or - 5 if I only want to display the commandline at the top. ( http://www.askapache.com/linux/bash-power-prompt.html )
275MB/748MB
[7995:7993 - 0:186] 06:26:49 Thu Apr 08 [askapache@n1-backbone5:/dev/pts/0 +1] ~
In most shells the LINES variable is created automatically at login and updated when the terminal is resized (28 linux, 23/20 others for SIGWINCH) to contain the number of vertical lines that can fit in your terminal window. Because the alias doesn't hard-code the current LINES but relys on the $LINES variable, this is a dynamic alias that will always work on a tty device.
change the time that you would like to have as print interval
and just use it to say whatever you want to
export THISOS="`uname -s`"
if [ "$THISOS" = "SunOS" ]
then
export THISRELEASE="`uname -r`"
ping1() { ping -s $1 56 1 | egrep "^64"; }
elif [ "$THISOS" = "AIX" ]
then
export THISRELEASE="`uname -v`.`uname -r`"
ping1() { ping -w ${2:-1} $1 56 1 | egrep "^64"; }
elif [ "$THISOS" = "Linux" ]
then
export THISRELEASE="`uname -r`"
ping1() { ping -c 1 -w ${2:-1} $1 | egrep "^64"; }
fi
I have used single packet, and in a silent mode with no display of ping stats. This is with color and UI improvement to the http://www.commandlinefu.com/commands/view/10220/check-if-a-machine-is-online. It is as per the enhancements suggested.
PING
parameters
c 1 limits to 1 pinging attempt
q makes the command quiet (or silent mode)
/dev/null 2>&1 is to remove the display
&& echo ONLINE is executed if previous command is successful (return value 0)
|| echo OFFLINE is executed otherwise (return value of 1 if unreachable or 2 if you're offline yourself).
I personally use this command as an alias with a predefined machine name but there are at least 2 improvements that may be done.
Asking for the machine name or IP
Escaping the output so that it displays ONLINE in green and OFFLINE in red (for instance).
Ever need to get some text that is a specific number of characters long? Use this function to easily generate it! Doesn't look pretty, but sure does work for testing purposes!
This is mostly for my own notes but this command will compute a md5 message digest from the command line.
You can also replace md5sum with other checksum commands (e.g., sha1sum)
uses the -u switch for UTC
Another way could be
echo $(($(date -ud "00:29:36" +%s)%86400))
Fast and excludes words with apostrophes. For ubuntu, you can use wamerican or wbritish dictionaries, installable through aptitude.
Generates a password using symbols, alpha, and digits. No repeating chars.
This is just a slight alternative that wraps all of #7917 in a function that can be executed
Are the two strings anagrams of one another?
sed splits up the strings into one character per line
the result is sorted
cmp compares the results
Note: This is not pretty. I just wanted to see if I could do it in bash.
Note: It uses fewer characters than the perl version :-)
displays current time in "binary clock" format
(loosely) inspired by: http://www.thinkgeek.com/homeoffice/lights/59e0/
"Decoding":
8421
.... - 1st hour digit: 0
*..* - 2nd hour digit: 9 (8+1)
.*.. - 1st minutes digit: 4
*..* - 2nd minutes digit: 9 (8+1)
Prompt-command version:
PROMPT_COMMAND='echo "10 i 2 o $(date +"%H%M"|cut -b 1,2,3,4 --output-delimiter=" ") f"|dc|tac|xargs printf "%04d\n"|tr "01" ".*"'