xargs enhancement: I collect new args while the last set is running, use a
fixed common buffer for input, and vary the arg count down for long args.
dgp@dgp-p6803w:~$ fxargs2
Usage: fxargs2 [ -n <args_per_exec> ] [ -v ] [ -p ] <cmd> [ <cmd_arg> ... ]
Reads arguments as lines from standard input and executes: <cmd> [ <cmd_args>
... ] <args_from_stdin>Each line becomes one argument. The number of args per
command is limitedby <args_per_exec> (default 1024). The command is executed
when either: - the total number of args from standard input is <args_per_exec>,
or - the buffer has ( 80 * <args_per_exec> ) unexecuted bytes of input, or -
stdin EOF is detected with any args from standard input.The <cmd> [ <cmd_args>
... ] is never executed alone.The buffer is fixed in size at 80 *
<args_per_exec>, so long args can forcefewer <args_per_exec> for any pass.While
a command is executing, reading resumes, but before another commandis executed,
the prior command must return a status.With -v, any abnormal child state
returned is reported.With -p, any child terminating on SIGPIPE causes a normal
exit.
dgp@dgp-p6803w:~$
I was tempted to exec more often if stdin was temporarily dry, but better is
the enemy of good enough!
-----Original Message-----
From: Paul Jackson <p...@usa.net>
To: David G. Pickett <dgpick...@aol.com>; egg...@cs.ucla.edu
<egg...@cs.ucla.edu>; 60...@debbugs.gnu.org <60...@debbugs.gnu.org>
Sent: Tue, Jan 3, 2023 5:32 pm
Subject: Re: bug#60506: feature: parallel grep --recursive
#yiv4580765374 p.yiv4580765374MsoNormal, #yiv4580765374
p.yiv4580765374MsoNoSpacing{margin:0;}#yiv4580765374 p.yiv4580765374MsoNormal,
#yiv4580765374 p.yiv4580765374MsoNoSpacing{margin:0;}David Pickett wrote:<< I
also wrote a simpler, line oriented, faster xargs, fxargs! >>
I've been quite pleased with an xargs wrapper I wrote that basically
converts newlines to nuls, and then invokes either "xargs" or, if asked
to run multiple threads, "parallel --xargs", passing all the "xargs" arguments
to "xargs --null".
I got all the exit status's and such just right, and preferred having all
thexargs options available, once this hack worked around the confused
space character handling of xargs without the --null option.
I call my wrapper "x", a short name since I use it a lot, having been a
regularxargs user since it was added to Version 7 Unix, inside Bell Labs, back
around
1978.
You can find my wrapper at:
http://thepythoniccow.us/x.c
By the way, even the original author of xargs, Herb Gellis, agrees that its
interface is somewhat borked. See a note Gellis posted a decade after writing
xargs, which I include in the above "x.c" source. An amusing bit of history ...
--
Paul Jackson
p...@usa.net
