How can this programe can count time , how to get this result ? can any one teach me in detail ?

#!/bin/bash

seconds=0

echo -n "Enter number of seconds > "
read seconds

hours=$((seconds / 3600))
seconds=$((seconds % 3600))
minutes=$((seconds / 60))
seconds=$((seconds % 60))

echo "$hours hour(s) $minutes minute(s) $seconds second(s)"

Enter number of seconds > 6001
1 hour(s) 40 minute(s) 1 second(s)

Enter number of seconds > 120
0 hour(s) 2 minute(s) 0 second(s)

Hi,

that's not exactly a count time program... that's more a convert time program
first: echo -n "sentence" to display the sentence and don't go to the next line
second: read value ... it displays a prompt (cursor) and wait for a value... the entered value is stored in value
Then that's maths
so it counts how many hours there's in value thanks to a division (3600 sec = 1 hr)... the result is stored in hour variable... it takes the rest of the division. Then it does the same for minutes...

Oliv'

OK, first:

1 hour = 60 minutes = 3600 seconds

You enter a number of seconds...

hours=$((seconds / 3600))

this divides your number of seconds by 3600 (discarding the remainder) to give you a number of hours.

seconds=$((seconds % 3600))

x % y means get the remainder of x / y, so this gets the "left over" number of seconds after the full hours have been removed. Note that this value then replaces the original value of the variable 'seconds'.

the next two lines do the same thing to the remaining seconds, only to calculate minutes instead.
The three variables are then printed out.

Does this help, or have I missed something?

Let's say, if I enter 5001

Enter number of seconds > 5001
1 hour(s) 23 minute(s) 21 second(s)

then

hours = 5001 /3600 -------------- =1.389...
seconds = 5001 % 3600 ----------- Reminder = 1401
and so on .....

I still don't know how to subsitude 5001 to this program to get the result .

5001 /3600 -------------- =1.389

Yes, that's what a calculator will give you - but the shell uses integer division, and discards the .389. You can see this for yourself by typing:
the output will just be 1. So the code sets $hours to 1, and moves on to replace $seconds with the remainder of 1401.
It then does the same thing with 1401 - divides by 60 to get $minutes, and the remainder replaces $seconds.

According to the programe, I try to subsitute 5001.

It most likely would be this.

hours=$((seconds / 3600))
seconds=$((seconds % 3600))
minutes=$((seconds / 60))
seconds=$((seconds % 60))

1=$(( 5001 / 3600))
1401=$(( 5001 % 3600))
23 =$(( 1401 / 60))
21=$((1401 % 60))

why the programe will choose 21 to be the seconds but not 1401 , is it programe will choose the last line for the final result ?

If I say:

x = 5

and then say:

x = x + 1

the right hand side (x+1) will be calculated, and then the value will be put into x. So when the program sees:

seconds = $((seconds % 60))

it does the calculation (current value of $seconds (1401) modulus 60, and then puts the answer (21) in $seconds. At any point after this line, $seconds is 21 - the value 1401 is 'lost' in the program.

#include<iostream>
using namespace std;

int main()
{

int hr,min,sec,i;

cout<<"\nEnter the time in seconds\n";
cin>>i;

hr=i/3600;
min=(i%3600)/60;
sec=(i%3600)%60;

cout<<"\nThe time in hr/min/sec format is "<<hr<<"/"<<min<<"/"<<sec;

return 0;
}