为什么 sh/bash 在尝试设置环境变量时会设置命令行参数值？
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Why does sh/bash set command line parameter values when trying to set environment variable?
提问by Touko
A question on basics : While tuning environment variables for a program launched from a script, I ended up with somewhat strange behaviour with sh (which seems to be actually linked to bash) : variable setting seems to mess up with command-line parameters.
关于基础知识的问题：在为从脚本启动的程序调整环境变量时，我最终对 sh 产生了一些奇怪的行为（这似乎实际上与 bash 相关联）：变量设置似乎与命令行参数混淆。
Could somebody explain why does this happen?
有人可以解释为什么会发生这种情况吗？
A simple script:
一个简单的脚本：
#! /bin/sh
# Messes with ??
set ANT_OPTS=-Xmx512M
export ANT_OPTS
# Works
# export ANT_OPTS=-Xmx512M
echo "0 = $ ./test.sh foo
0 = ./test.sh
1 = ANT_OPTS=-Xmx512M
"
echo "1 = "
When I run this with the upper alternative (set + export), the result is as following:
当我使用上层替代（set + export）运行它时，结果如下：
$ ./test.sh foo
0 = ./test.sh
1 = foo
But with lower alternative (export straight), the result is as I supposed:
但是使用较低的替代方案（直接导出），结果正如我所想的：
ANT_OPTS=-Xmx512m
export ANT_OPTS
There is surely logical explanation, I just haven't figured it out yet. Somebody who does have idea?
肯定有合乎逻辑的解释，只是我还没有弄清楚。有人有想法吗？
br, Touko
br，东子
回答by Hank Gay
You should just use ANT_OPTS=-Xmx512Minstead of set ANT_OPTS=-Xmx512M.
你应该只使用ANT_OPTS=-Xmx512M而不是set ANT_OPTS=-Xmx512M.
UPDATE: See herefor discussion of set, and the manual.
回答by Paul Tomblin
"set" isn't part of setting variables in Bourne Shell. That should be
“set”不是在 Bourne Shell 中设置变量的一部分。那应该是
##代码##