Shell Tips! - Latest Comments

Re: 4. How to Check if a Bash Array contains a value

Prince Chawla — Mon, 30 Mar 2020 06:28:04 -0000

this article helped to me solve my problem.
Thanks. :)

Re: How To Upgrade your Bash Version on MacOS | Shell Tips!

Doug W — Thu, 12 Mar 2020 14:33:02 -0000

Finally, a proper write up! Thanks, this worked.

Re: Performing Math calculation in Bash

Anonymous — Fri, 31 Jan 2020 09:59:44 -0000

A bit strange to put black text on a dark green background

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

Alex — Tue, 25 Jun 2019 22:57:56 -0000

We were trying to do restorations with Rubrik backups and the permissions weren't being set on the files post restoration. This fixed it. Thanks!

Re: Performing Math calculation in Bash

gerlos — Mon, 28 May 2018 07:42:02 -0000

There's nothing to fix, as said the result si correct.
There's no practical difference between 1 and 0.99999999999999999999.

Re: Performing Math calculation in Bash

George Tanner — Sun, 27 May 2018 16:29:50 -0000

BP=$(echo "scale=2; $NumBurgers*$Price" |bc)

Re: Performing Math calculation in Bash

Мирослав Кашеба — Sun, 04 Feb 2018 10:08:54 -0000

I don't recommend to use 'calc' as name for function, because already exist calculator, named 'calc'. A way better than 'bc'. You can install it by "sudo apt install apcalc". You can simply use floating point operations without any additional options.
Actually I was searching page for full manual or tutorial for 'calc' in Google.

#using your example:
calc 2+3*8/7
~5.42857142857142857143
#

Also 'calc' support math functions (sin(x), cos(x), tan(x), exp(x), sqrt(x), log(x), ln(x), x^y (raising 'x' to power 'y'), ...) and many more.
using:
calc "expression"
#or
calc <press enter="">
#writing expressions
exit

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

Niall Byrne — Thu, 01 Feb 2018 19:53:42 -0000

Life saver. Had issue using Wing Personal to debug python code on centOS 7 permissions issue running subproc() command required password.
This was way around it.

Re: Performing Math calculation in Bash

Vivek Kumar Maurya — Mon, 13 Nov 2017 04:21:55 -0000

Nice tutorial. very helpful. thanks for uploading.

Re: LINUX : How to reload or change your current shell ?

Pothi Kalimuthu — Tue, 24 Oct 2017 00:08:24 -0000

That's nice way. Thanks.

To improve on it, we could use...

exec $SHELL

which would work for all shells.

Re: Performing Math calculation in Bash

kreezxil — Thu, 28 Sep 2017 09:33:03 -0000

These tips still work, although I would've put the "awk" example before the "bc" example considering it tends to come preinstalled with most Linux distributions including the new "Linux subsystems for Windows" as provided by creator preview editions if enabled by the user.

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

lanerfy — Mon, 11 Sep 2017 00:01:27 -0000

salamat po!

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

_nd345-SysAdmin — Tue, 27 Jun 2017 08:50:05 -0000

thank you, the "by command" was useful.

Re: Performing Math calculation in Bash

Natan Felles — Fri, 23 Jun 2017 20:45:22 -0000

Thank you!

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

AET — Thu, 13 Apr 2017 05:03:26 -0000

ssh -t user@host -t 'sudo whatever'
as the manual says and from above:

Multiple -t options force tty allocation, even if ssh has no local tty.
Did not try -tt which also likely works.

Re: Performing Math calculation in Bash

Jeňa Kočí — Fri, 17 Mar 2017 07:13:56 -0000

to quote from R Inferno (1st Circle):

"Do not confuse numerical error with an error. An error is when a computation is wrongly performed. Numerical error is when there is visible noise resulting from the finite representation of numbers. It is numerical error—not an error—when one-third is represented as 33%."

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

Wellington Oliveira — Fri, 10 Mar 2017 07:04:31 -0000

Obrigado. Me ajudou :]

Re: Performing Math calculation in Bash

Michal — Wed, 01 Mar 2017 10:39:25 -0000

You miss $ before myvar:

myvar=$(expr 1 + $myvar)

Re: Performing Math calculation in Bash

SvennD — Fri, 10 Feb 2017 06:16:26 -0000

Thanks, nice trick the | bc

Re: Performing Math calculation in Bash

Jeňa Kočí — Sun, 29 Jan 2017 11:34:11 -0000

Thanks, very good tutorial :) I was wondering about this for a while and never googled it till now - I should stick to my "google everything" rule more often :)

Re: Advanced Math Calculation in Bash Using GNU Bc

australia assignment help — Mon, 05 Sep 2016 02:10:16 -0000

It looks new to anyone who wasn't able to undergo this kind of learning. From this, there would truly be some other techniques that can guide them and would help them in solving those topics in mathematics.

Re: Performing Math calculation in Bash

essay writing service — Tue, 21 Jun 2016 10:07:14 -0000

It's really interesting that in performing mathematics there are some programs that are capable in doing it. For sure, there will be a lot of people who will going to try this up and could help them to apply it on their work.

Re: Sudo: Sorry, You Must Have a Tty to Run Sudo

noname418 — Fri, 04 Dec 2015 15:49:54 -0000

any tips for "cssh"? ("Cluster ssh" version 4.x)

Re: Performing Math calculation in Bash

gerlos — Tue, 03 Nov 2015 07:08:14 -0000

It's because of rounding errors: https://en.wikipedia.org/wi...

It's not nice for us humans ;-) bu the answer is essentially the right number: in almost all the real applications you can't tell the difference between 1 and 0.99999999999999999999! :-)

For a nicer output just round it adding a pipe like this: | python -c "print round(float(raw_input()))"

Re: Flash – How to fix the “Security sandbox violation: BitmapData.draw”

Mary Burczynski — Tue, 18 Aug 2015 06:42:46 -0000

I am not a developer but I keep getting this flash player dialog pop up I have IE 11. I never had this pop up before updating to flash 18...So I deleted flash player. Apparently there is a built in flash player in IE 11? I need to know how to get rid of the pop up error box, the latest error was,Security sandbox violation...Please tell me how to disable this dialog box..It's very annoying.thank you.