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Full Discussion: cp output /dev/null results in not a directory
Top Forums UNIX for Dummies Questions & Answers cp output /dev/null results in not a directory Post 302318548 by stevesmo on Thursday 21st of May 2009 10:03:55 PM
Old 05-21-2009
cp output /dev/null results in not a directory
Hello,
I am working on a script to measure the read performance of a busybox environment. The logical choice is to use a command line like:

(time cp * /dev/null) 2> /tmp/howlong.txt

Ah, the rub is cp or /dev/null will only accept a single file at a time.
The result in the txt file is and output list that basically shows /dev/null/filename Not a directory.

I tried the same with using dd if=* of=/dev/null bs=1M, alas the results were similar.

I tried using a for loop, but I could not get time to work with syntax errors.

Example:

Works:
for FILE * cp $FILE /dev/null ; done

Fails:
(time for FILE * cp $FILE /dev/null ; done) 2> /tmp/howlong.txt

Any help here would be appreciated.
Thanks,

-Steve
 

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LEARN ABOUT OSF1

mkmanifest

mkmanifest(1)						      General Commands Manual						     mkmanifest(1)

NAME

       mkmanifest - mtools utility to create a shell script to restore UNIX file names from DOS

SYNOPSIS

       mkmanifest [files]

OPTIONS

       None

OPERANDS

       A list of UNIX file names to be converted to DOS name format.

DESCRIPTION

       The  mkmanifest	command creates a shell script that aids in the restore of UNIX file names that were overwritten by DOS file name restric-
       tions.  DOS file names are uppercase only, cannot exceed 8 character names, 3 character extensions and do not support device names or  non-
       alphanumeric characters.

       Not all UNIX file names are supported in the DOS world.	The mtools commands may have to change UNIX names to fit the DOS file name conven-
       tions.  Most commands provide the verbose option (-v), that displays new file names if they have been changed. The  following  table  shows
       some examples of file name conversions:

       -----------------------------------------------
       UNIX name     DOS name	Reason for the change
       -----------------------------------------------
       thisisatest   THISISAT	file name too long
       file.stuff    FILE.STU	extension too long
       prn.txt	     XRN.TXT	PRN is a device name
       .abc	     X.ABC	null file name
       hot+cold      HOTXCOLD	illegal character
       -----------------------------------------------

EXIT STATUS

       The following exit values are returned: Success.  Failure.

EXAMPLES

       Assume you have the following UNIX files that you want to copy to a DOS diskette using the mcopy command.

       very_long_name 2.many.dots illegal: good.c prn.dev Capital

       The mcopy command converts these file names to the following:

       very_lon 2xmany.dot illegalx good.c xprn.dev capital

       To restore the previous file names, use the mkmanifest command as follows: mkmanifest very_long_name 2.many.dots illegal:       
				  good.c prn.dev Capital > manifest

       The  previous  mkmanifest command line produces the following: mv very_lon very_long_name mv 2xmany.dot 2.many.dots mv illegalx illegal: mv
       xprn.dev prn.dev mv capital Capital

       The good.c file name did not require conversion, hence it was not included in the output.

       If these files were copied from diskette to another UNIX system, and you wanted to restore the original names, retain a copy of	the  mani-
       fest file (captured output) so that it can be used to convert the file names again.

FILES

       Executable file

SEE ALSO

       Commands: mcopy(1), mtools(1)

																     mkmanifest(1)
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