Re: patch for review: xargs standards compliance

On Fri, Mar 22, 2002 at 04:06:32PM +0000, J. Mallett wrote:

> One thing I am now unsure of that I'd forgotten all about is:
> 	"Constructed arguments cannot grow larger than 255 bytes. "
> 
> Should I errx() if strlen(*tmp) is >255, or should I augment strnsubst() 
> to take a size argument and not allow more than that amount to be 
> allocated, and furthermore, do I strlcat replstr for each match, or do I 
> do checks along the way to see if it is time to give up on replacing, and 
> just concatenate the rest of the string.  I *think* given the language 
> relating to umber of replacements in the argument list, that I should TRY 
> to replace as many times as possible, up to five...

$ echo hello | xargs -I xxx echo `perl -e 'print "A"x255;'`xxx
xargs: Maximum argument size with insertion via xxx's exceeded
Segmentation Fault
$ uname -sr
SunOS 5.8

Since SUS is biased towards SysV, you should probably print an error message
and exit like Solaris tries to; no need for you to segfault like they
do though ;)

Also:
$ echo hello | xargs -Ixxx a xxx b xxx c xxx d xxx e xxx f xxx
xargs: too many args with xxx

So it seems you should quit with an error when either of these limits
are reached. This seems to be a flaw in the standard because these
limits are (a) artifically low and (b) cannot be raised by implementors.


Tim

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