Update Command-line Output, i.e. for Progress

Question

I'd like to be able to show a progress meter in a simple PHP script on the command line. Instead of seeing

Progress: 0%
Progress: 1%
etc...

I'd like just the number to change, and replace the previous number, much like git clone does for example Resolving deltas: 100% (8522/8522), done..

While searching for this I found the same question answered in Perl, which is perfect, but I couldn't find it in PHP. Is it possible? If not, I'll resort to C.

Thanks

Update: If anyone's interested in the C++ version, it's here.

Coinage

usually php has finished its job before anything is sent to the browser, what's the script doing? – Salmi

@Dagon he is using command-line – Cereus

doh! thanks, sounds even odder then the only php command line i do is for me, its hardly suitable for a user interface. – Salmi

Yes, it's on the command-line. It's just for simple scripts, for personal use: updating project version number, transferring files somewhere, etc.. Nothing user-facing – Coinage

seems pointless to then add a progress bar. But then i'm always function over form. – Salmi

@Dagon Well, I suppose there is a user - me. Sometimes it's nice to have an idea of how long something might take. And in this case, form doesn't impeed function, afaik – Coinage

real men don't need pretty progress bars :-) – Salmi

I just released my progressbar implementation github.com/Ex3v/PHP-ProgressBar – Evacuee

https://mcmap.net/q/276288/-clear-php-cli-output – Sphere

@Coinage Please consider changing best answer. – Elect

@Arek which would you suggest. Any reason? – Coinage

"\r" looks simple and clean, but "\033" gives more control. Never mind. – Elect

Answer 1

This can be done using ANSI Escape Sequences -- see here for a list.

In PHP, you'll use "\033" when it's indicated ESC on that page.

In your case, you could use something like this :

echo "Progress :      ";  // 5 characters of padding at the end
for ($i=0 ; $i<=100 ; $i++) {
    echo "\033[5D";      // Move 5 characters backward
    echo str_pad($i, 3, ' ', STR_PAD_LEFT) . " %";    // Output is always 5 characters long
    sleep(1);           // wait for a while, so we see the animation
}

I simplified a bit, making sure I always have 5 extra characters, and always displaying the same amount of data, to always move backwards by the same number of chars...

But, of course, you should be able to do much more complicated, if needed ;-)

And there are many other interesting escape sequences : colors, for instance, can enhance your output quite a bit ;-)

Cereus

PHP > 5.4.0 now have "\e" to write ESC – Linear

this one works in windows https://mcmap.net/q/276288/-clear-php-cli-output – Sphere

Answer 2

Just for the record though an old thread: Instead of using fancy ANSI Escape sequencing to move the curser back I just move it back to the beginning of the line using "\r" instead of to the beginning of the next line "\n". Add a few spaces after your echo to overwrite anything that was there previously, like e.g. so:

for ($i=0 ; $i<=100 ; $i++) {
  echo "Progress: $i %   \r";
  sleep(1);
}

Wehrmacht

Works like a charm, also on Windows! (tested) – Ephraim

Much easier than the solution with the most upvotes - works perfectly on OSX. – Diverticulitis

much better solution – Miraflores

also you can use usleep for big collection – Ally

you're a genius ! Works fine in Windows command line window ! – Nasia

This probably doesn't answer the original question better than the accepted answer, BUT it is likely more useful for what most people are looking for when they come across this question. – Fink

That's amazing！very useful！ – Dryfoos