How to make a “progress bar” using printf? [duplic

Question

This question already has answers here:

How to display a progress indicator in pure C/C++ (cout/printf)? (8 answers)

Closed 6 years ago.

Many command line tools implement text-based progress bar. Like rpm installing:

installing ##############[45%]

the # grows with the percentage, while keeps itself in a single line. What I want is something similar: I need a progress indicator taking just one line, that is to say, when percentage grows, it got overwritten, instead of make a new line(\n).

I tried this:

   #include <stdio.h>

   int main (){
       int i = 0;
       for (i = 0; i < 10000; i++){
           printf("\rIn progress %d", i/100);
       }
       printf("\n");
   }

\r works to overwrite the single line. However, \r brings cursor to the beginning of line and printf brings cursor to the end, which result in a rapidly waving cursor. You guys can feel it by a little compiling. Can Anyone come up with alternatives to avoid this issue?

Answer 1

This is a problem of the stdout stream being buffered. You have to flush it explicitly (implicit flushing occurs with a \n) using fflush(stdout) after the printf():

fflush(stdout);

Answer 2

To use formatting on your terminal, check the ANSI escape code.

Answer 3

Rather than giving your some erroneous and non-portable code lines, I'd recommend you to read through the man pages for your system's termcap and terminfo. It's a bit hard to follow at first, but it's a must-read if your about to start mucking with terminal-dependent code. The Wikipedia pages are a good place to start, but then do give the man pages on your system a read as well.

Also I just realized your question is most definitely a duplicate of a few other questions.

Answer 4

I believe using

printf("\e[?25l");

may be able to help. This will hide the cursor. Honestly, I'm not sure if using /r or printf again will override that bit of code and show the cursor, but it's worth a shot. Also, the below code can be used to show the cursor again.

printf("\e[?25h");

Answer 5

Here is how the rpm did it, maybe you can write a similar for your own purpose: printHash.

rpm use \b instead of \r to erase the output line character by character.