Re: Too many filename matches

Altera_Forum · ‎10-12-2011

Hello,

I got a system that records to a Compact Flash disk. Everything works great except when I try to delete a bunch of files using rm *.dat. It gives me the message:

"Too many filename matches".

I also have the problem that when we have several files, "ls" hangs up.

I tried to get the rm command off the Busybox, but I'm getting errors when I compile the OS.

Please advice

Altera_Forum · ‎10-12-2011

Hi. I don't know busybox but I know linux.

The parse of "*.dat" seems to exceed the max number of arguments.

"ls" hangs up but responds later (very later) I think.

A begin of an idea (remove by groups):

rm a*.dat

rm b*.dat

...

Altera_Forum · ‎10-12-2011

mmTushi,

Thanks for the prompt response. We are removing the data files in smaller groups as you pointed out. But this is a royal pain, very slow tedious process.

Is there any way one can change the max number of arguments?

The default settings have rm in Busybox. I like to try rm outside of Busybox. What do I need to change in the uClinux settings to accomplish this?

Thanks

Altera_Forum · ‎10-12-2011

you could try a bash script:

#!/bin/bash
for file in $PWD/*
do
        if ]
        then
                rm $file
        fi
done

Altera_Forum · ‎10-13-2011

The usual way to avoid the argument limit is using 'xargs', typically:

find . -name '*.dat' | xargs rmalthough in your case:

echo *.dat | xargs rmmay well work, but I'm not sure busybox has xargs.

You could so something like (untested):

rm_all()
{
    while 
    do
        rm "$1" "$2" "$3" "$4" "$5" "$6" "$7" "$8" "$9"
        shift 9
    done
    rm "$@"
}
rm_all *.dat

Since it is likely that the shell function argument limit is larger than that for exec.

Altera_Forum · ‎10-13-2011

I'm trying to enable bash, but I get the following error:

In function 'make_child':

/pathname/nios2-linux/uClinux-dist/user/bash/jobs.c:1147: undefined reference to 'fork'

How do I fix this?

Thanks

Altera_Forum · ‎10-14-2011

I added xargs to busybox, and I tried the command

echo *.dat | xargs rm

same result:

Too many filename matches

Where in busybox is the maximum number of arguments defines, does anybody know?

Thanks

Altera_Forum · ‎10-14-2011

That constraint will be in the shell, it might be an argument count limit, or a byte length limit. Try searching the source tree for the error message!

The kernel will have its own limit - but that need not apply to shell builtins.

The 'Too many filename matches' error might even be coming from the part of the shell that expands the wildcard - rather than part of the attempt to run a program. If the error is returned by "set -- *.dat" then you probably wont get the shell to expand the list anywhere.

That means you'll need to use something else to generate the list of names, 'find' or 'ls .' will work - with the latter you'll need to filter the unwanted names yourself.

You also won't want to run 'rm' for every file - unless you add it as a shell builtin - because of the fork+exec costs.

You might actually be able to use: find . -name '*.dat' -delete

Altera_Forum · ‎10-14-2011

Yes!!

find . -name '*.dat' -delete

Works just fine.

Thanks for the help