Re: Find file that contains "....." (command in Unix)

Good solution, but you could run into trouble if the resulting command line is bigger than the maximum size supported by the OS.

Of course, you will only run into trouble if your xargs is broken. The point of using xargs is to avoid the problem you are describing.

The disadvantage of using -exec is that find will spawn a grep process for each file found, while with the use of xargs, far less processes will be spawned.

Abigail

Comment on Re: Find file that contains "....." (command in Unix)

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Re: Re: Find file that contains "....." (command in Unix) by bronto (Priest) on Mar 28, 2003 at 10:09 UTC
Of course, you will only run into trouble if your xargs is broken. The point of using xargs is to avoid the problem you are describing. ++Abigail-II. The fact was not mentioned on my Linux' `xargs` man page. But it was on Solaris': The generated command line length will be the sum of the size in bytes of the utility name and each argument treated as strings, including a null byte terminator for each of these strings. The xargs utility will limit the command line length such that when the command line is invoked, the com- bined argument and environment lists will not exceed {ARG_MAX}-2048 bytes. Within this constraint, if neither the -n nor the -s option is specified, the default command line length will be at least {LINE_MAX}. Not very clear, indeed. But one can go by abstraction `:-)` and suppose that the line length limit will be circumvented! Thanks, I learnt something new! Ciao! `--bronto` The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway). --John M. Dlugosz	[reply] [d/l]

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Re: Re: Find file that contains "....." (command in Unix)
by bronto (Priest) on Mar 28, 2003 at 10:09 UTC

Of course, you will only run into trouble if your xargs is broken. The point of using xargs is to avoid the problem you are describing.

++Abigail-II. The fact was not mentioned on my Linux' xargs man page. But it was on Solaris':

     The generated command line length will be  the  sum  of  the
     size  in bytes of the utility name and each argument treated
     as strings, including a null byte  terminator  for  each  of
     these strings. The xargs utility will limit the command line
     length such that when the command line is invoked, the  com-
     bined   argument  and  environment  lists  will  not  exceed
     {ARG_MAX}-2048 bytes. Within this constraint, if neither the
     -n  nor the -s option is specified, the default command line
     length will be at least {LINE_MAX}.

Not very clear, indeed. But one can go by abstraction :-) and suppose that the line length limit will be circumvented!

Thanks, I learnt something new!

Ciao!
--bronto

The very nature of Perl to be like natural language--inconsistant and full of dwim and special cases--makes it impossible to know it all without simply memorizing the documentation (which is not complete or totally correct anyway).
--John M. Dlugosz

[reply]
[d/l]