为什么 sh/bash 在尝试设置环境变量时设置命令行参数值？
关于基础知识的问题：在调整从脚本启动的程序的环境变量时，我最终遇到了 sh 的一些奇怪的行为（它似乎实际上链接到 bash）：变量设置似乎与命令行参数混淆。
有人可以解释为什么会发生这种情况吗？
一个简单的脚本：
#! /bin/sh
# Messes with $1 ??
set ANT_OPTS=-Xmx512M
export ANT_OPTS
# Works
# export ANT_OPTS=-Xmx512M
echo "0 = $0"
echo "1 = $1"
当我使用上面的替代方案（设置+导出）运行它时，结果如下：
$ ./test.sh foo
0 = ./test.sh
1 = ANT_OPTS=-Xmx512M
但是使用较低的替代方案（直接导出），结果如我所想：
$ ./test.sh foo
0 = ./test.sh
1 = foo
肯定有逻辑解释，我只是没有'还没弄清楚。有人有想法吗？
br、图子
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.
Could somebody explain why does this happen?
A simple script:
#! /bin/sh
# Messes with $1 ??
set ANT_OPTS=-Xmx512M
export ANT_OPTS
# Works
# export ANT_OPTS=-Xmx512M
echo "0 = $0"
echo "1 = $1"
When I run this with the upper alternative (set + export), the result is as following:
$ ./test.sh foo
0 = ./test.sh
1 = ANT_OPTS=-Xmx512M
But with lower alternative (export straight), the result is as I supposed:
$ ./test.sh foo
0 = ./test.sh
1 = foo
There is surely logical explanation, I just haven't figured it out yet. Somebody who does have idea?
br, Touko
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您应该只使用
ANT_OPTS=-Xmx512M而不是set ANT_OPTS=-Xmx512M。更新：请参阅此处了解
set的讨论和手册。You should just use
ANT_OPTS=-Xmx512Minstead ofset ANT_OPTS=-Xmx512M.UPDATE: See here for discussion of
set, and the manual.“set”不是 Bourne Shell 中设置变量的一部分。那应该是
"set" isn't part of setting variables in Bourne Shell. That should be