bash 和 linux 内核中的 Shebang 行限制
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/10813538/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Shebang line limit in bash and linux kernel
提问by sortega
I'm trying to execute python scripts automatically generated by zc.buildout so I don't have control over them. My problem is that the shebang line (#!) is too long for either bash (80 character limit) or direct execution (some Linux kernel constant I don't know).
我正在尝试执行由 zc.buildout 自动生成的 python 脚本，因此我无法控制它们。我的问题是shebang行（#！）对于bash（80个字符限制）或直接执行（我不知道的一些Linux内核常量）来说太长了。
This is an example script to help you reproduce my problem:
这是一个示例脚本，可帮助您重现我的问题：
#!/././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././././bin/bash
echo Hola!
How can be bash or the kernel configured to allow for bigger shebang lines?
如何配置 bash 或内核以允许更大的 shebang 行？
回答by Ignacio Vazquez-Abrams
Limited to 127 chars on 99.9% of systems due to kernel compile time buffer limit.
由于内核编译时缓冲区限制，在 99.9% 的系统上限制为 127 个字符。
It's limited in the kernel by BINPRM_BUF_SIZE, set in include/linux/binfmts.h.
它在内核中受限于BINPRM_BUF_SIZE，在 中设置include/linux/binfmts.h。
回答by glenn Hymanman
If you don't want to recompile your kernel to get longer shebang lines, you could write a wrapper:
如果您不想重新编译内核以获得更长的 shebang 行，您可以编写一个包装器：
#!/bin/bash
if [[ $# -eq 0 ]]; then
echo "usage: ${0##*/} script [args ...]"
exit
fi
# we're going to expand a variable *unquoted* to use word splitting, but
# we don't want to have path expansion effects, so turn that off
set -f
shebang=$(head -1 "")
if [[ $shebang == '#!'* ]]; then
interp=( ${shebang#\#!} ) # use an array in case a argument is there too
else
interp=( /bin/sh )
fi
# now run it
exec "${interp[@]}" "$@"
and then run the script like: wrapper.sh script.sh
然后运行脚本，如： wrapper.sh script.sh
回答by coderfi
Updated @glenn Hymanman's script to support passing in command line arguments.
更新了@glenn Hymanman 的脚本以支持传入命令行参数。
Incidentally, I ran into this problem when creating a python virtualenv inside of a very deep directory hierarchy.
顺便说一句，我在非常深的目录层次结构中创建 python virtualenv 时遇到了这个问题。
In my case, this was a virtualenv created inside a Mesos framework dir.
就我而言，这是在 Mesos 框架目录中创建的 virtualenv。
The extra long shebang rendered calling xxx/.../venv/bin/pipuseless.
超长的shebang使调用变得xxx/.../venv/bin/pip无用。
The wrapper script proved most useful.
包装脚本被证明是最有用的。
#!/usr/bin/env bash
script=""
shebang=$(head -1 "$script")
# use an array in case a argument is there too
interp=( ${shebang#\#!} )
# now run it, passing in the remaining command line arguments
shift 1
exec "${interp[@]}" "$script" "${@}"
