Progress Bar in C for an arbitrary long execution -- CONSOLE - c

Question

I have tried my best to search not only stackOverflow but other website as well but could not find something to match my needs. What I am requesting is to be able to display a progress bar (e.g. Progress: ####.........). I don't really care for the % at the moment.
Now lies the problem. I can not simply do a 0-100 for loop as the code I wish to have executed and tracked lies within a while loop that runs for an arbitrary time (problem size depends on input of user thus, is not constant).
I have thought of keeping track of the number of iterations within an int variable and try to do a modulo by 2, 50 or 100 but as I have said, the number of iterations depends on the users input and thus, only manageable under specific conditions. No other output but the progress bar is done so I do a simple printf('#'); inside the while loop and all the pretty stuff outside it.
This is also a personal preference but don't mind if not included, I would like the progress bar to be 50 characters long so 100% execution = 50 '#' characters accordingly.
Any help is kindly appreciated.

Answer 1

So i wrapped the code from before nicelly and here is what i ended up with.
I used a little bit of oop concept and simulated the class of a ProgressBar. Here is how i designed the code for the ProgressBar:
struct tagProgressBarData
{
unsigned long nMaxLen;
unsigned long nCurLen;
char FillChr;
char EmptyChr;
char LeftMargin;
char RightMargin;
};
typedef struct tagProgressBarData PBD;
void InitProgressBar(PBD* p, unsigned long MaxLen, char Left, char Right, char Fill, char Empty);
void DrawProgressBar(PBD* p);
Before jumping to the definitions of InitProgressBar() and DrawProgressBar(), this is how you should use what i've made. Here is an example:
int main()
{
PBD data;
/** You can chose other characters and change the length too! */
InitProgressBar(&data, 50, '[', ']', '#', '.');
/** Now we do something which takes some time. */
/** Let's just calculate some random cubes. */
/** The N you talked about. */
unsigned int N;
printf("How many numbers to compute: ");
scanf("%u", &N);
printf("Calculating the cubes of the first %u numbers.\n", N);
DrawProgressBar(&data);
for(unsigned int i = 1; i <= N; i++)
{
unsigned int CubeResult = i*i*i;
unsigned long nProgress = ( ((unsigned long long)i) * data.nMaxLen) / N;
if (nProgress != data.nCurLen)
{
data.nCurLen = nProgress;
DrawProgressBar(&data);
}
}
return 0;
}
And now, the definition of the function that prints the progress bar:
void DrawProgressBar(PBD* p)
{
/** Move to the beginning of the line. */
printf("\r");
/** Print the left margin char. */
printf("%c", p->LeftMargin);
/** Make sure that MaxLen >= CurLen */
if (p->nMaxLen < p->nCurLen)
p->nCurLen = p->nMaxLen;
/** Print the progress with the Fill char. */
for(unsigned long i = 0; i < p->nCurLen; i++)
printf("%c", p->FillChr);
/** Complete whats left with the Fill char. */
for(unsigned long i = 0; i < p->nMaxLen - p->nCurLen; i++)
printf("%c", p->EmptyChr);
/** Print the right margin char. */
printf("%c", p->RightMargin);
}
I have also used this function to make my code in main more compact:
void InitProgressBar(PBD* p, unsigned long MaxLen, char Left, char Right, char Fill, char Empty)
{
p->nMaxLen = MaxLen;
p->nCurLen = 0;
p->LeftMargin = Left;
p->RightMargin = Right;
p->FillChr = Fill;
p->EmptyChr = Empty;
}
If you want to have some text before the progress bar but on the same line (something like Progress: [######.............]) you have to replace the printf("\r"); from the DrawProgressBar() with a for loop so you move back exactly the length of the progress bar.
Also, you need some variable (let's say bDrawn) which will tell you if the progress bar has been drawn at least once, so that the for loop will not move the cursor over the existing text at the left of the progress bar.

Answer 2

After trial and error, I may have found a solution but would like to check against someone.
Assuming these variables (all of type int):
num_iterations = 0, MAX_PROGRESS = 100, BAR_LENGTH = 50, num_items = N
I have printed a '#' character on:
if ((iteration / BAR_LENGTH) % (MAX_PROGRESS * BAR_LENGTH * num_items) == 0)
and get my desired result:
|<------------- Enumeration Complete ------------->|
|##################################################| COMPLETED
Though this gradually builds up, it is not of the form
|<------------- Enumeration Complete ------------->|
|##################################................|
Anything I can do with \r or \b?

Answer 3

I have also done this but seems to be very dependent on the number of items.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
int MAX_PROGRESS = 100;
int BAR_LENGTH = 0; // Length of Header
int num_items = 30;
void delay(int milliseconds) {
// Storing start time
clock_t start_time = clock();
// looping till required time is not achieved
while (clock() < start_time + milliseconds);
}
void initialiseProgressBar(char left, char right, char fill) {
printf("%c", left);
for (int i = 0; i < BAR_LENGTH; i ++) {
printf("%c", fill);
}
/** Print the right first (end of line) and then again the left (start of line)
* as the \r will be placed over it and rewrite from there resulting in one
* character less
*/
printf("%c\r%c", right, left);
}
void drawProgressBar(char c) {
// Print according to BAR_LENGTH
for (int i = 0; i < 100; i ++) {
double progress = (i / BAR_LENGTH) % (MAX_PROGRESS * BAR_LENGTH * num_items);
if (progress == 0) {
printf("%c", c);
delay(25);
}
// Redraw the stdout stream to show progressing bar
fflush(stdout);
}
}
int main(int argc, char* argv[]) {
// Header
char* header = "|<------------- Progress Bar ------------->|\n";
printf("%s", header);
BAR_LENGTH = strlen(header) - 3; // Account for newline and right character characters
initialiseProgressBar('[', ']', '.');
drawProgressBar('#');
// Footer -- TODO Find better way to finish this without hard coding
printf("] COMPLETED\n");
return 0;
}
Assuming you know the number of items you are calculating against (e.g. sorting a list, calculating different things etc), this should come in handy :).