Add support for busybox

[BKPepe]

Someone requested to have nnn in OpenWrt, there is preinstalled busybox, which provides several utilities. One of these utilities is xargs, which does not have the option a.

xargs: unrecognized option: a
BusyBox v1.30.1 () multi-call binary.

Usage: xargs [OPTIONS] [PROG ARGS]

Run PROG on every item given by stdin

    -p    Ask user whether to run each command
    -r    Don't run command if input is empty
    -0    Input is separated by NULs
    -t    Print the command on stderr before execution
    -e[STR]    STR stops input processing
    -n N    Pass no more than N args to PROG
    -s N    Pass command line of no more than N bytes
    -x    Exit if size is exceeded

Because of that, there needs to be installed coreutils-xargs. Other things like copy, move, rm works with provided tools by busybox. It would be good if it can use just busybox utilities.

Environment details (Put x in the checkbox along with the information)

[x] Operating System: OpenWrt

[jarun]

Please test with the patch and confirm.

@KlzXS can you please review the changes thoroughly? I am extremely worried about dropping the -o.

[BKPepe]

That's was fast! Thanks. I will try it and let you know.

[KlzXS]

Immediately I can see that it no longer asks me if I want to overwrite files, which could be a bit of a problem. I say that we should keep -o. There is -p but that's a bit too much.

Other than that files are still copied, moved and removed like they were. Maybe get someone to test the trash feature, I don't think I have that setup. I'll test it more in depth later if we decide to go ahead with this, but I'm also unsure about dropping -o.

[BKPepe]

Now, it shows: xargs: unrecognized option: I

[jarun]

@KlzXS and @BKPepe

I have reverted the earlier patch. The indicative code is in git history still. I can't break a utility working perfectly on tons of platforms because one platform can't install findutils. The changes are extremely risky and I can't get these tested on multiple platforms immediately.

I can think of the following alternatives:

• add findutils as a dependency of nnn as in other platforms (even Termux does the same)
• add a compile-time flag for busybox and setup the xargs commands correctly (this won't be simple given how rudimentary/crippled BusyBox xargs is)

[jarun]

@BKPepe with PR #388 we are on for BusyBox! Please test and confirm if everything works.

The credit for this goes to @KlzXS!

[BKPepe]

I will take a look at it. Thanks!

[BKPepe]

I've just tested it and works. Good work!

[jarun]

Thanks for confirming! I'm closing the defect. Please feel free to let us know if you need anything else in nnn.