Will 'xargs' help on "parameter list too long"?

[Rob_132]

I need to

ls dir/*o

such that the output is

dir/file1.o
dir/file2.o

But, if there are too many files in the directory, I get the "parameter list too long" error message.

I believe that I can still get the desired output (shown above) when there are too many files - using the 'xargs' command - but am unclear on the syntax.

Help on this would be most appreciated!

Thanks in advance.

[Steven E. Protter]

I don't know a lot about this, but I'm attaching an example that might prove useful.

SEP

[Stefan Farrelly]

yes, xargs will do it. simply do;

ls dir/*o | xargs

[G. Vrijhoeven]

Hi,

I am afraid it would not work for the ls. It could work for input commands.

ls dir | grep 'o$'

There are limits you can reach and the are defined in /usr/include/limits.h

I would nod advice you to change those but they will give you some insight.

Gideon

[Jean-Louis Phelix · Accepted solution]

Hi,

Try :

find dir -name '*.o'

Regards.

[Rob_132]

Another case of taking something simple and turning it into a complex problem!

SEP - may have netted more points w/ attachmnet

SF - same error message

GV - OK, except omits dir name

JLP - Works! Thanks!

** Thread closed **

Thanks all!

[A. Clay Stephenson]

Xargs will not help in this case because the *.o is instantiated by the shell before xargs gets a chance to operate on it. We can leverage the find command and restrict this to a single directory using -path. This will work because -path './dir/*.o' is evaluated by find without the shell expanding it first BUT ONLY if quoted.

This will work for you:
find . -path './dir/*.o' -exec ls -l {} \;
or simply
find . -path './dir/*.o'
if all you want to do is list the .o files only in dir.

Now for a valid (and more efficient) use of xargs to replace the -exec clause in the command above:

find . -path './dir/*.o' | xargs ls -l

[Jean-Luc Oudart]

Furthermore...

find . -path './dir/*.o' | xargs ls -l10

This will reduce the number of processes (buffer=10)

Regards,
Jean-Luc

[Rob_132]

...and 10 for Clay for the insightful explanation that accompanied his response.

Rob

[Jean-Luc Oudart]

Sorry ..
please read xargs -l10
e.g.
xargs -l10 ll

regards,
Jean-Luc

[Rob_132]

0 on last for assigning 9 to "errant" earlier post. The second post really deserves the 9....

Thanks for the clarification.

Back to work, now. Thanks again!

** CLOSED **

[doug hosking]

PHKL_11092 and related fixes may also be relevant in some situations. Prior to these patches, there was a 20K byte limit on the sum of the environment size plus the size of all arguments to an exec* family call. These patches raised the limit from 20K to 2MB.

(There were actually several fixes for this, even within the same OS release.)

Proper use of xargs (as already noted) is still a good idea, especially in cases where you can't know for sure if relevant patches have been installed. In situations where you truly need to pass a program more than 20K of arguments, the kernel patches may be helpful.