[Question] The order of files that gets processed changes randomly?

[someonenameguy]

In the red boxes the filenames changes randomly even thought the files are already sorted by name, only the first one stays the same.
Anyone knows what's happening?

[andrews05]

oxipng processes multiple files in parallel, adding each one to a thread pool. The order that files will be completed is indeed non-deterministic. You can disable this if necessary by setting --threads 1.

[someonenameguy]

I see. I'll set it to single-thread for future processing.

[andrews05]

Alternatively you can execute oxipng separately for each item, which allow it to still use multiple threads for optimisation. You may be able to do this by adding -L 1 to xargs, or by using a loop as I mentioned in your previous thread #586 (comment) (apologies if I closed that prematurely, did you manage to get it sorted by time?).

[someonenameguy]

I kinda give up trying to sort by time since the files in Twitter\X are named by date and some id. so doing ls sorts them by date.

I just tried running ls -rw 1 | xargs -r -L 1 oxipng -po 4 it to runs the same as -threads 1.
I checked with echo seems fine though.

ls -rw 1 | xargs -r -L 1 echo oxipng -po 4 
...
oxipng -po 4 20240114_163924.png                               oxipng -po 4 20240101_165454.png
oxipng -po 4 20231229_104644.png                               oxipng -po 4 20231229_104456.png
oxipng -po 4 20231229_104356.png                               oxipng -po 4 20231228_214504.png
oxipng -po 4 20231223_182621.png                               oxipng -po 4 20231221_123639.png
oxipng -po 4 20231218_011109.png                               oxipng -po 4 20231218_011107.png
oxipng -po 4 20231205_163829.png                               oxipng -po 4 20231205_071650.png
oxipng -po 4 20231130_233753.png                               oxipng -po 4 20231127_075119.png
oxipng -po 4 20231127_075118.png                               oxipng -po 4 20231124_003135.png
oxipng -po 4 20231124_002800.png                               oxipng -po 4 20231123_161119.png
oxipng -po 4 20231123_161114.png                               oxipng -po 4 20231117_123806.png
oxipng -po 4 20231111_095818.png                               oxipng -po 4 20231111_004448.png
oxipng -po 4 20231111_003354.png                               oxipng -po 4 20231111_003352.png
oxipng -po 4 20231110_083845.png                               oxipng -po 4 20231110_072440.png
^C

The looping one doesn't work simply because termux uses Bash not Zsh, I get and error on the (Om) part.

for f in *.png(Om); do oxipng -po 4 $f; done
bash: syntax error near unexpected token `('

[andrews05]

I kinda give up trying to sort by time since the files in Twitter\X are named by date and some id. so doing ls sorts them by date.

Ah right, that seems sensible.

I just tried running ls -rw 1 | xargs -r -L 1 oxipng -po 4 it to runs the same as -threads 1. I checked with echo seems fine though.

Yeah, so the advantage is it should be noticeably faster than completely disabling multithreading.

[someonenameguy]

Yeah, so the advantage is it should be noticeably faster than completely disabling multithreading.

oxipng uses multi-threading for single images? Didn't know that, I'll use ls *.png -rw 1 | xargs -r -L 1 oxipng -po 4 in the future.
At least only 1477 of 22888 files in there are pngs.

Thanks/Thank you for the help be the way.