我有一个脚本,我不希望它调用退出,如果它是来源。

我想检查是否$0 == bash,但这有问题,如果脚本是从另一个脚本,或者如果用户从不同的shell,如ksh源。

是否有一种可靠的方法来检测脚本是否被引用?


当前回答

看了@DennisWilliamson的回答后,有一些问题,如下所示:

因为这个问题代表ksh和bash,所以这个答案中还有一个关于ksh的部分…见下文。

简单的bash方式

[ "$0" = "$BASH_SOURCE" ]

让我们试试(在飞行中,因为bash可以;-):

source <(echo $'#!/bin/bash
           [ "$0" = "$BASH_SOURCE" ] && v=own || v=sourced;
           echo "process $$ is $v ($0, $BASH_SOURCE)" ')
process 29301 is sourced (bash, /dev/fd/63)

bash <(echo $'#!/bin/bash
           [ "$0" = "$BASH_SOURCE" ] && v=own || v=sourced;
           echo "process $$ is $v ($0, $BASH_SOURCE)" ')
process 16229 is own (/dev/fd/63, /dev/fd/63)

我用source代替off。对于可读性(如。是源的别名):

. <(echo $'#!/bin/bash
           [ "$0" = "$BASH_SOURCE" ] && v=own || v=sourced;
           echo "process $$ is $v ($0, $BASH_SOURCE)" ')
process 29301 is sourced (bash, /dev/fd/63)

注意,当进程保持源时,进程号不会改变:

echo $$
29301

为什么不使用$_ == $0比较

为了确保更多的情况,我开始编写一个真实的脚本:

#!/bin/bash

# As $_ could be used only once, uncomment one of two following lines

#printf '_="%s", 0="%s" and BASH_SOURCE="%s"\n' "$_" "$0" "$BASH_SOURCE"
[[ "$_" != "$0" ]] && DW_PURPOSE=sourced || DW_PURPOSE=subshell

[ "$0" = "$BASH_SOURCE" ] && BASH_KIND_ENV=own || BASH_KIND_ENV=sourced;
echo "proc: $$[ppid:$PPID] is $BASH_KIND_ENV (DW purpose: $DW_PURPOSE)"

复制到testscript文件:

cat >testscript   
chmod +x testscript

现在我们可以测试:

./testscript 
proc: 25758[ppid:24890] is own (DW purpose: subshell)

没关系。

. ./testscript 
proc: 24890[ppid:24885] is sourced (DW purpose: sourced)

source ./testscript 
proc: 24890[ppid:24885] is sourced (DW purpose: sourced)

没关系。

但是,在添加-x标志之前测试脚本:

bash ./testscript 
proc: 25776[ppid:24890] is own (DW purpose: sourced)

或者使用预定义的变量:

env PATH=/tmp/bintemp:$PATH ./testscript 
proc: 25948[ppid:24890] is own (DW purpose: sourced)

env SOMETHING=PREDEFINED ./testscript 
proc: 25972[ppid:24890] is own (DW purpose: sourced)

这已经不管用了。

将注释从第5行移到第6行会给出更易读的答案:

./testscript 
_="./testscript", 0="./testscript" and BASH_SOURCE="./testscript"
proc: 26256[ppid:24890] is own

. testscript 
_="_filedir", 0="bash" and BASH_SOURCE="testscript"
proc: 24890[ppid:24885] is sourced

source testscript 
_="_filedir", 0="bash" and BASH_SOURCE="testscript"
proc: 24890[ppid:24885] is sourced

bash testscript 
_="/bin/bash", 0="testscript" and BASH_SOURCE="testscript"
proc: 26317[ppid:24890] is own

env FILE=/dev/null ./testscript 
_="/usr/bin/env", 0="./testscript" and BASH_SOURCE="./testscript"
proc: 26336[ppid:24890] is own

更难:ksh现在…

由于我不经常使用ksh,在阅读了一些手册页后,有我的尝试:

#!/bin/ksh

set >/tmp/ksh-$$.log

复制到testfile.ksh:

cat >testfile.ksh
chmod +x testfile.ksh

而不是运行两次:

./testfile.ksh
. ./testfile.ksh

ls -l /tmp/ksh-*.log
-rw-r--r-- 1 user user   2183 avr 11 13:48 /tmp/ksh-9725.log
-rw-r--r-- 1 user user   2140 avr 11 13:48 /tmp/ksh-9781.log

echo $$
9725

看看:

diff /tmp/ksh-{9725,9781}.log | grep ^\> # OWN SUBSHELL:
> HISTCMD=0
> PPID=9725
> RANDOM=1626
> SECONDS=0.001
>   lineno=0
> SHLVL=3

diff /tmp/ksh-{9725,9781}.log | grep ^\< # SOURCED:
< COLUMNS=152
< HISTCMD=117
< LINES=47
< PPID=9163
< PS1='$ '
< RANDOM=29667
< SECONDS=23.652
<   level=1
<   lineno=1
< SHLVL=2

在源运行中继承了一些变量,但没有什么真正相关的…

你甚至可以检查$SECONDS是否接近0.000,但这是为了确保只有手工来源的情况……

你甚至可以试着检查parent是什么:

把它放在你的testfile.ksh:

ps $PPID

比:

./testfile.ksh
  PID TTY      STAT   TIME COMMAND
32320 pts/4    Ss     0:00 -ksh

. ./testfile.ksh
  PID TTY      STAT   TIME COMMAND
32319 ?        S      0:00 sshd: user@pts/4

或者ps ho cmd $PPID,但这只适用于一个级别的子会话…

对不起,我找不到一个可靠的方法来做,在ksh下。

其他回答

检测Bash脚本是否正在执行或导入的最漂亮方法

我真的认为这是最美丽的方式:

从我的eRCaGuy_hello_world repo中的if__name__==__main__ check_if_sourced_or_executed_best.sh文件:

#!/usr/bin/env bash

main() {
    echo "Running main."
    # Add your main function code here
}

if [ "${BASH_SOURCE[0]}" = "$0" ]; then
    # This script is being run.
    __name__="__main__"
else
    # This script is being sourced.
    __name__="__source__"
fi

# Only run `main` if this script is being **run**, NOT sourced (imported)
if [ "$__name__" = "__main__" ]; then
    echo "This script is being run."
    main
else
    echo "This script is being sourced."
fi

引用:

关于上述技术的其他详细信息,请参见我在这里的另一个回答,包括显示运行输出:bash与Python的if __name__ == '__main__'等价于什么? 这个答案,我第一次了解到“${BASH_SOURCE[0]}”=“$0”

如果您愿意,还可以探索以下替代方案,但我更喜欢使用上面的代码块。

重要提示:使用“${FUNCNAME[-1]}”技术不能正确处理嵌套脚本,即一个脚本调用或来源另一个脚本,而if ["${BASH_SOURCE[0]}" = "$0"]技术可以。这是使用if ["${BASH_SOURCE[0]}" = "$0"]的另一个重要原因。

4种方法确定bash脚本是源脚本还是执行脚本

我已经阅读了关于这个问题和其他一些问题的一堆答案,并提出了4种我想要总结并放在一个地方的方法。

if __name__ == "__main__":

参见:如果__name__ == "__main__":会做什么?在Python中所做的事情。

You can see a full demonstration of all 4 techniques below in my check_if_sourced_or_executed.sh script in my eRCaGuy_hello_world repo. You can see one of the techniques in-use in my advanced bash program with help menu, argument parsing, main function, automatic execute vs source detection (akin to if __name__ == "__main__": in Python), etc, see my demo/template program in this list here. It is currently called argument_parsing__3_advanced__gen_prog_template.sh, but if that name changes in the future I'll update it in the list at the link just above

不管怎样,这里有4个Bash技术:

Technique 1 (can be placed anywhere; handles nested scripts): See: https://unix.stackexchange.com/questions/424492/how-to-define-a-shell-script-to-be-sourced-not-run/424495#424495 if [ "${BASH_SOURCE[0]}" -ef "$0" ]; then echo " This script is being EXECUTED." run="true" else echo " This script is being SOURCED." fi Technique 2 [My favorite technique] (can be placed anywhere; handles nestes scripts): See this type of technique in-use in my most-advanced bash demo script yet, here: argument_parsing__3_advanced__gen_prog_template.sh, near the bottom. Modified from: What is the bash equivalent to Python's `if __name__ == '__main__'`? if [ "${BASH_SOURCE[0]}" == "$0" ]; then echo " This script is being EXECUTED." run="true" else echo " This script is being SOURCED." fi Technique 3 (requires another line which MUST be outside all functions): Modified from: How to detect if a script is being sourced # A. Place this line OUTSIDE all functions: (return 0 2>/dev/null) && script_is_being_executed="false" || script_is_being_executed="true" # B. Place these lines anywhere if [ "$script_is_being_executed" == "true" ]; then echo " This script is being EXECUTED." run="true" else echo " This script is being SOURCED." fi Technique 4 [Limitation: does not handle nested scripts!] (MUST be inside a function): Modified from: How to detect if a script is being sourced and Unix & Linux: How to define a shell script to be sourced not run. if [ "${FUNCNAME[-1]}" == "main" ]; then echo " This script is being EXECUTED." run="true" elif [ "${FUNCNAME[-1]}" == "source" ]; then echo " This script is being SOURCED." else echo " ERROR: THIS TECHNIQUE IS BROKEN" fi This is where I first learned about the ${FUNCNAME[-1]} trick: @mr.spuratic: How to detect if a script is being sourced - he learned it from Dennis Williamson apparently.

参见:

[我的回答]bash相当于Python的if __name__ == '__main__'? [我的回答]Unix和Linux:如何定义一个shell脚本来获取而不是运行

看了@DennisWilliamson的回答后,有一些问题,如下所示:

因为这个问题代表ksh和bash,所以这个答案中还有一个关于ksh的部分…见下文。

简单的bash方式

[ "$0" = "$BASH_SOURCE" ]

让我们试试(在飞行中,因为bash可以;-):

source <(echo $'#!/bin/bash
           [ "$0" = "$BASH_SOURCE" ] && v=own || v=sourced;
           echo "process $$ is $v ($0, $BASH_SOURCE)" ')
process 29301 is sourced (bash, /dev/fd/63)

bash <(echo $'#!/bin/bash
           [ "$0" = "$BASH_SOURCE" ] && v=own || v=sourced;
           echo "process $$ is $v ($0, $BASH_SOURCE)" ')
process 16229 is own (/dev/fd/63, /dev/fd/63)

我用source代替off。对于可读性(如。是源的别名):

. <(echo $'#!/bin/bash
           [ "$0" = "$BASH_SOURCE" ] && v=own || v=sourced;
           echo "process $$ is $v ($0, $BASH_SOURCE)" ')
process 29301 is sourced (bash, /dev/fd/63)

注意,当进程保持源时,进程号不会改变:

echo $$
29301

为什么不使用$_ == $0比较

为了确保更多的情况,我开始编写一个真实的脚本:

#!/bin/bash

# As $_ could be used only once, uncomment one of two following lines

#printf '_="%s", 0="%s" and BASH_SOURCE="%s"\n' "$_" "$0" "$BASH_SOURCE"
[[ "$_" != "$0" ]] && DW_PURPOSE=sourced || DW_PURPOSE=subshell

[ "$0" = "$BASH_SOURCE" ] && BASH_KIND_ENV=own || BASH_KIND_ENV=sourced;
echo "proc: $$[ppid:$PPID] is $BASH_KIND_ENV (DW purpose: $DW_PURPOSE)"

复制到testscript文件:

cat >testscript   
chmod +x testscript

现在我们可以测试:

./testscript 
proc: 25758[ppid:24890] is own (DW purpose: subshell)

没关系。

. ./testscript 
proc: 24890[ppid:24885] is sourced (DW purpose: sourced)

source ./testscript 
proc: 24890[ppid:24885] is sourced (DW purpose: sourced)

没关系。

但是,在添加-x标志之前测试脚本:

bash ./testscript 
proc: 25776[ppid:24890] is own (DW purpose: sourced)

或者使用预定义的变量:

env PATH=/tmp/bintemp:$PATH ./testscript 
proc: 25948[ppid:24890] is own (DW purpose: sourced)

env SOMETHING=PREDEFINED ./testscript 
proc: 25972[ppid:24890] is own (DW purpose: sourced)

这已经不管用了。

将注释从第5行移到第6行会给出更易读的答案:

./testscript 
_="./testscript", 0="./testscript" and BASH_SOURCE="./testscript"
proc: 26256[ppid:24890] is own

. testscript 
_="_filedir", 0="bash" and BASH_SOURCE="testscript"
proc: 24890[ppid:24885] is sourced

source testscript 
_="_filedir", 0="bash" and BASH_SOURCE="testscript"
proc: 24890[ppid:24885] is sourced

bash testscript 
_="/bin/bash", 0="testscript" and BASH_SOURCE="testscript"
proc: 26317[ppid:24890] is own

env FILE=/dev/null ./testscript 
_="/usr/bin/env", 0="./testscript" and BASH_SOURCE="./testscript"
proc: 26336[ppid:24890] is own

更难:ksh现在…

由于我不经常使用ksh,在阅读了一些手册页后,有我的尝试:

#!/bin/ksh

set >/tmp/ksh-$$.log

复制到testfile.ksh:

cat >testfile.ksh
chmod +x testfile.ksh

而不是运行两次:

./testfile.ksh
. ./testfile.ksh

ls -l /tmp/ksh-*.log
-rw-r--r-- 1 user user   2183 avr 11 13:48 /tmp/ksh-9725.log
-rw-r--r-- 1 user user   2140 avr 11 13:48 /tmp/ksh-9781.log

echo $$
9725

看看:

diff /tmp/ksh-{9725,9781}.log | grep ^\> # OWN SUBSHELL:
> HISTCMD=0
> PPID=9725
> RANDOM=1626
> SECONDS=0.001
>   lineno=0
> SHLVL=3

diff /tmp/ksh-{9725,9781}.log | grep ^\< # SOURCED:
< COLUMNS=152
< HISTCMD=117
< LINES=47
< PPID=9163
< PS1='$ '
< RANDOM=29667
< SECONDS=23.652
<   level=1
<   lineno=1
< SHLVL=2

在源运行中继承了一些变量,但没有什么真正相关的…

你甚至可以检查$SECONDS是否接近0.000,但这是为了确保只有手工来源的情况……

你甚至可以试着检查parent是什么:

把它放在你的testfile.ksh:

ps $PPID

比:

./testfile.ksh
  PID TTY      STAT   TIME COMMAND
32320 pts/4    Ss     0:00 -ksh

. ./testfile.ksh
  PID TTY      STAT   TIME COMMAND
32319 ?        S      0:00 sshd: user@pts/4

或者ps ho cmd $PPID,但这只适用于一个级别的子会话…

对不起,我找不到一个可靠的方法来做,在ksh下。

这在后面的脚本中起作用,不依赖于_变量:

## Check to make sure it is not sourced:
Prog=myscript.sh
if [ $(basename $0) = $Prog ]; then
   exit 1  # not sourced
fi

or

[ $(basename $0) = $Prog ] && exit

如果您的Bash版本知道BASH_SOURCE数组变量,请尝试如下操作:

# man bash | less -p BASH_SOURCE
#[[ ${BASH_VERSINFO[0]} -le 2 ]] && echo 'No BASH_SOURCE array variable' && exit 1

[[ "${BASH_SOURCE[0]}" != "${0}" ]] && echo "script ${BASH_SOURCE[0]} is being sourced ..."

我将给出一个特定于bash的答案。Korn shell,对不起。假设脚本名为include2.sh;然后在include2.sh中创建一个名为am_I_sourced的函数。下面是我的include2.sh的演示版本:

am_I_sourced()
{
  if [ "${FUNCNAME[1]}" = source ]; then
    if [ "$1" = -v ]; then
      echo "I am being sourced, this filename is ${BASH_SOURCE[0]} and my caller script/shell name was $0"
    fi
    return 0
  else
    if [ "$1" = -v ]; then
      echo "I am not being sourced, my script/shell name was $0"
    fi
    return 1
  fi
}

if am_I_sourced -v; then
  echo "Do something with sourced script"
else
  echo "Do something with executed script"
fi

现在尝试以多种方式执行它:

~/toys/bash $ chmod a+x include2.sh

~/toys/bash $ ./include2.sh 
I am not being sourced, my script/shell name was ./include2.sh
Do something with executed script

~/toys/bash $ bash ./include2.sh 
I am not being sourced, my script/shell name was ./include2.sh
Do something with executed script

~/toys/bash $ . include2.sh
I am being sourced, this filename is include2.sh and my caller script/shell name was bash
Do something with sourced script

所以这是毫无例外的工作,它没有使用脆弱的$_东西。这个技巧使用了BASH的自省功能,即内置变量FUNCNAME和BASH_SOURCE;请参阅bash手册页中的文档。

只有两个警告:

1)对am_I_called的调用必须发生在源脚本中,而不是在任何函数中,以免${FUNCNAME[1]}返回其他东西。是的…您本可以检查${FUNCNAME[2]},但这样做只会使您的工作更加困难。

2)函数am_I_called必须驻留在源脚本中,如果你想知道被包含的文件的名称。