The program should check that the input files does exist about pipe-rename

[Stargateur]

it does no ? What is the behavior you would expect ?

I guess an option, ignore error could be add. But this as default behavior seem right to me.

[bew]

Okay, I agree with you it isn't a good explanation of the problem at all (didn't have much time when I thought about this...)

The check we see is currently at the very end (and it doesn't really look like a check, more like that the syscall to rename the file didn't work).
I get an error after I did the name changes I wanted etc.. But if the initial file name does not exist, my changes are of no use at all, and I'd have to re-make all the changes when I re-run the program with the correct file names.

I would have expected it to show an error immediately instead.

[Stargateur]

and it doesn't really look like a check, more like that the syscall to rename the file didn't work

that the best, the OS will check anyway

I would have expected it to show an error immediately instead.

That could be an option indeed

[marcusbuffett]

I agree that getting an error right away would be better, it would be annoying to have a bunch of renames pending and then it errors out because you misspelled a file name when invoking the command, would be better to get an error right away. Hasn't been a problem for me in practice, since tab-completion and piping ls into it doesn't end up with non-existent files, but I can see it happening with other use cases, I'm in favor of this change 👍