$ true | xargs echo no data
no data
$ true | xargsL echo no data # No output
给xargsL的任何参数都将传递给xargs。
下面是"xargsL" POSIX shell脚本:
#! /bin/sh
# Line-based version of "xargs" (one pathname per line which may contain any
# amount of whitespace except for newlines) with the added bonus feature that
# it will not execute the command if the input file is empty.
#
# Version 2018.76.3
#
# Copyright (c) 2018 Guenther Brunthaler. All rights reserved.
#
# This script is free software.
# Distribution is permitted under the terms of the GPLv3.
set -e
trap 'test $? = 0 || echo "$0 failed!" >& 2' 0
if IFS= read -r first
then
{
printf '%s\n' "$first"
cat
} | sed 's/./\\&/g' | xargs ${1+"$@"}
fi
-exec command {} +
This variant of the -exec action runs the specified command on
the selected files, but the command line is built by appending
each selected file name at the end; the total number of invoca‐
matched files. The command line is built in much the same way
that xargs builds its command lines. Only one instance of `{}'
is allowed within the command, and (when find is being invoked
from a shell) it should be quoted (for example, '{}') to protect
it from interpretation by shells. The command is executed in
the starting directory. If any invocation returns a non-zero
value as exit status, then find returns a non-zero exit status.
If find encounters an error, this can sometimes cause an immedi‐
ate exit, so some pending commands may not be run at all. This
variant of -exec always returns true.