Commands using bc sorted by votes

Commands using bc (53)

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Define a quick calculator function

defines a handy function for quick calculations from cli. once defined: ? 10*2+3 Show Sample Output
This is sample output - yours may be different.
```
23?
```
58

? () { echo "$*" | bc -l; }

fizz · 2009-06-28 20:15:30 27
Convert seconds into minutes and seconds

This is a very simple way to input a large number of seconds and get a more useful value in minutes and seconds. Avoids useless use of echo. Show Sample Output
This is sample output - yours may be different.
```
 04 59
```
26

bc <<< 'obase=60;299'

mathias · 2011-10-21 13:15:17 9
Base conversions with bc

Easily convert numbers to their representations in different bases. Passing "ibase=16; obase=8; F2A" to bc will convert F2A (3882 in decimal) from Hex to Octal, and so on. Show Sample Output
This is sample output - yours may be different.
```
$ echo "obase=2; 27" | bc -l
11011
$ echo "ibase=16; F2A" | bc -l
3882
$ echo "ibase=16; obase=8; F2A" | bc -l
7452
```
20

echo "obase=2; 27" | bc -l

polar · 2009-03-25 09:54:50 39
Get the total length of all videos in the current dir in H:m:s

You're behind on your TV catch-up, but how far behind? This command tries to open mplayer against all files in the current dir. If it's a video file it will contain ID_LENGTH, which is summed and output in hours, minutes and seconds. Someone better at awk could probably reduce this down a lot. Show Sample Output
This is sample output - yours may be different.
```
30529.18
8h:28m:49s
```
5

mplayer -vo dummy -ao dummy -identify * 2>&1 | grep ID_LENGTH | sed 's/.*=$[0-9]*$/\1/' | xargs echo | sed 's/ /+/g' | bc | awk 'S=$1; {printf "%dh:%dm:%ds\n",S/(60*60),S%(60*60)/60,S%60}'

Strawp · 2009-09-24 10:33:19 6
convert from decimal to hexadecimal

Use the standard calculator bc to convert decimals to hex Show Sample Output
This is sample output - yours may be different.
```
$ hex 65535
FFFF
```
4

hex() { bc <<< "obase=16; $1"; }

bjomape · 2011-12-09 13:57:05 11
memcache affinity: queries local memcached for stats, calculates hit/get ratio and prints it out.

queries local memcached for stats, calculates hit/get ratio and prints it out. Show Sample Output
This is sample output - yours may be different.
```
95.23223087607411631700
```
3

echo -en "stats\r\n" "quit\r\n" | nc localhost 11211 | tr -s [:cntrl:] " "| cut -f42,48 -d" " | sed "s/$[0-9]*$\s$[0-9]*$/ \2\/\1*100/" | bc -l

magictoken · 2009-02-21 15:55:37 5
floating point operations in shell scripts

-l auto-selects many more digits (but you can round/truncate in your head, right) plus it loads a few math functions like sin(). Show Sample Output
This is sample output - yours may be different.
```
.56464247339503535720
```
3

bc -l <<< s(3/5)

akg240 · 2009-09-02 15:41:39 9
Print CPU load in percent

Faster then all other commands here at cmdlinefu with the same purpose. Show Sample Output
This is sample output - yours may be different.
```
1 minute load average: 37.0%
```
3

printf "1-minute load average: %.1f%%\n" \ $(bc <<<"$(cut -d ' ' -f 1 /proc/loadavg) * 100")

wuseman1 · 2019-07-04 14:07:03 48
Calculate pi to an arbitrary number of decimal places
This is sample output - yours may be different.
3

bc -l <<< "scale=1000; 4*a(1)"

cryptology_codes · 2020-03-11 15:58:21 74
quick integer CPU benchmark

This is a quick and dirty way to generate a (non-floating-point) CPU-bound task to benchmark. Adjust "20" to higher or lower values, as needed. As a benchmark this is probably a little less bogus than bogomips, and it will run anywhere 'bc' does. Show Sample Output
This is sample output - yours may be different.
```
7.14user 0.00system 0:07.16elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+944minor)pagefaults 0swaps
```
2

echo '2^2^20' | time bc > /dev/null

mkc · 2009-02-06 02:31:55 38
doing some floating point math
This is sample output - yours may be different.
2

echo "8000000/(20*6*86400)" | bc -l

skygreg · 2009-02-19 17:05:20 5
Quick calculator at the terminal

Useful for quick calculations at the command line. $math_expr is any arithmetic expression (see sample output): 4.5*16+3^2 s(3.1415926/2) More options in the bc man page. Show Sample Output
This is sample output - yours may be different.
```
$ echo "4.5*16+3^2" | bc -l
81.0
$ echo "s(3.1415926/2)" | bc -l
.99999999999999964101
```
2

echo "$math_expr" | bc -l

polar · 2009-03-25 09:46:01 5
Generate trigonometric/log data easily
This is sample output - yours may be different.
2

echo "e("{1..8}");" | bc -l

unefunge · 2010-11-18 21:18:22 2
Compute the average number of KB per file for each dir

Use this to find identify if dirs mostly contain large or small files. Show Sample Output
This is sample output - yours may be different.
```
yeslab.org 300.32786885245901639344
theyesmen.org 679.16801687505732016752
```
2

parallel echo -n {}"\ "\;echo '$(du -s {} | awk "{print \$1}") / $(find {} | wc -l)' \| bc -l ::: *

unixmonkey8046 · 2011-07-28 12:21:34 4
Uniquely (sort of) color text so you can see changes

Colorify colors input by converting the text to a number and then performing modulo 7 on it. This resulting number is used as the color escape code. This can be used to color the results of commands with complex outputs (like "482279054165371") so if any of the digits change, there's a good chance the color will change too. I say good chance because there's only 7 unique colors here, so assuming you were watching random numbers, there would be a 6/7 chance that the color would change when the number changed. This should really only be used to help quickly identify when things change, but should not be the only thing relied upon to positively assert that an output has not changed. Show Sample Output
This is sample output - yours may be different.
```
$ colorify test
test (shows as orange)
$ colorify test2
test2 (shows as purple)
```
2

function colorify() { n=$(bc <<< "$(echo ${1}|od -An -vtu1 -w100000000|tr -d ' ') % 7"); echo -e "\e[3${n}m${1}\e[0m"; }

tyzbit · 2020-08-06 15:17:45 394
Doing some floating point calculations with rounding (e.g. at the 3rd decimal)
This is sample output - yours may be different.
1

echo '123/7' |bc -l |xargs printf "%.3f\n"

mrttlemonde · 2009-03-18 14:20:32 5
Beep siren

Infinitely plays beeps with sinusoidally changing sound frequency. Ideal for alarm on an event.
This is sample output - yours may be different.
1

tempo=33; slope=10; maxfreq=888; function sinus { echo "s($1/$slope)*$maxfreq"|bc -l|tr -d '-'; }; for((i=1;;i++)); do beep -l$tempo -f`sinus $i`; done

5z474n · 2009-07-10 21:24:11 3
Floating point power p of x

One pipe less. Show Sample Output
This is sample output - yours may be different.
```
1.41421356237309504878
```
1

bc -l <<< "x=2; p=0.5; e(l(x)*p)"

akg240 · 2009-09-04 15:50:48 5
Command line calculator
This is sample output - yours may be different.
1

calc() { bc <<< $*; }

hemanth · 2010-10-07 08:44:28 5
Uptime in minute

Want to run scripts/programs in the system after starting X minute [ For letting the system to free ]? This will give uptime in minute.
This is sample output - yours may be different.
1

bc <<< `uptime | sed -e 's/^.*up //' -e 's/[^0-9:].*//' | sed 's/:/*60+/g'`

totti · 2011-08-29 10:24:43 14
Calculate pi with specific scale

a() function in bc is for arctangent, available if using -l option included. Show Sample Output
This is sample output - yours may be different.
```
3.1415926532
```
1

echo 'scale=10; 4*a(1)' | bc -l

chars19 · 2012-10-08 15:03:07 8

Calculate pi to an arbitrary number of decimal places

Change the scale to adjust number of decimal places prefix the command with "time" to benchmark the computer (compare how long it takes to calculate 10000 digits of pi on various computers). Show Sample Output

echo "scale=1000; 4*a(1)" | bc -l

regulatre · 2014-07-31 19:13:26 4

Run CPU benchmark from command line

Run CPU benchmark from command line
This is sample output - yours may be different.
1

time echo "scale=5000; 4*a(1)" | bc -l -q

nitrogear · 2016-09-25 18:21:53 17
small CPU benchmark with PI, bc and time.

# 4 cores with 2500 pi digits CPUBENCH 4 2500 . every core will use 100% cpu and you can see how fast they calculate it. if you do 50000 digitits and more it can take hours or days Show Sample Output
This is sample output - yours may be different.
```
CPUBENCH 3 5000
Cores: 3
Digit: 5000

real	0m18.680s
user	0m18.678s
sys	0m0.005s

real	0m18.901s
user	0m18.869s
sys	0m0.035s

real	0m18.902s
user	0m18.899s
sys	0m0.005s
```
1

CPUBENCH() { local CPU="${1:-1}"; local SCALE="${2:-5000}"; { for LOOP in `seq 1 $CPU`; do { time echo "scale=${SCALE}; 4*a(1)" | bc -l -q | grep -v ^"[0-9]" & } ; done }; echo "Cores: $CPU"; echo "Digit: $SCALE" ;}

emphazer · 2018-05-14 17:30:37 192
function to compute what percentage of X is Y? Where percent/100 = X/Y => percent=100*X/Y

This function make it easy to compute X/Y as a percentage. The name "wpoxiy" is an acronym of "what percentage of X is Y" Show Sample Output
This is sample output - yours may be different.
```
$ wpoxiy 65788574 1269501
1.92%

$ wpoxiy 30 10
33.33%
```
1

function wpoxiy () { # What percentage of X is Y? Where percent/100 = X/Y => percent=100*X/Y # Example: wpoxiy 10 5 # 50.00% # Example: wpoxiy 30 10 # 33.33% echo $(bc <<< "scale=2; y=${1}; x=${2}; percent=x*100/y; percent")"%"; }

mpb · 2018-06-10 22:43:20 240
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Kill google chrome process

Get absolut path to your bash-script

Find usb device in realtime

Using this command you can track a moment when usb device was attached.

find large files

Merge PDFs into single file

Prepend a text to a file.

The original command is great, but I often want to prepend to every line.

Wait for file to stop changing

This loop will finish if a file hasn't changed in the last 10 seconds. . It checks the file's modification timestamp against the clock. If 10 seconds have elapsed without any change to the file, then the loop ends. . This script will give a false positive if there's a 10 second delay between updates, e.g. due to network congestion . How does it work? 'date +%s' gives the current time in seconds 'stat -c %Y' gives the file's last modification time in seconds '$(( ))' is bash's way of doing maths '[ X -lt 10 ]' tests the result is Less Than 10 otherwise sleep for 1 second and repeat . Note: Clever as this script is, inotify is smarter.

Set a Reminder for yourself via the notification system

This will be seen through your system's visual notification system, notify-osd, notification-daemon, etc. --- sleep accepts s,m,h,d and floats (date; sleep .25m; date) --- notify-send (-t is in milliseconds && -u low / normal / critical) man notify-send for more information --- notification-daemon can use b/i/u/a HTML

retrieve the source address used to contact a given host

on multihomed hosts, connected to several networks, could be usefull to know the source address (local ip address) used to reach the target host, this command does not require root priviledges. The command use a TCP socket, if there is any error the command return an empty string, elsewhere return a valid ip address.

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Commands using bc (53)

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