如何定义一个不运行的 shell 脚本

假设您正在运行 bash，请将以下代码放在您想要获取但不执行的脚本的开头附近：

if [ "${BASH_SOURCE[0]}" -ef "$0" ]
then
    echo "Hey, you should source this script, not execute it!"
    exit 1
fi

在 bash 下，${BASH_SOURCE[0]}将包含 shell 正在读取的当前文件的名称，无论它是被获取还是被执行。

相比之下，$0是当前正在执行的文件的名称。

-ef测试这两个文件是否是同一个文件。如果是，我们会提醒用户并退出。

POSIX也不-ef是。BASH_SOURCE虽然-ef受 ksh、yash、zsh 和 Dash 支持，但BASH_SOURCE需要 bash。 但是zsh，${BASH_SOURCE[0]}可以替换为${(%):-%N}。

一个不可执行的文件可以被获取但不能被执行，因此，作为第一道防线，不设置可执行标志应该是一个很好的提示......

编辑：我刚刚偶然发现的技巧：使shebang成为不是shell解释器的任何可执行文件，/bin/false使脚本返回错误（rc！= 0）

#!/bin/false "This script should be sourced in a shell, not executed directly"

这篇 Stack Overflow 帖子中建议了几种方法，其中我最喜欢Wirawan Purwanto和mr.spuratic建议的基于函数的方法：

正如 Wirawan Purwanto 所建议的，最可靠的方法是 FUNCNAME[1] 在函数内进行检查：

function mycheck() { declare -p FUNCNAME; }
mycheck

然后：

$ bash sourcetest.sh
declare -a FUNCNAME='([0]="mycheck" [1]="main")'
$ . sourcetest.sh
declare -a FUNCNAME='([0]="mycheck" [1]="source")'

这相当于检查caller、值 的输出main并source区分调用者的上下文。使用 FUNCNAME[]可以节省您捕获和解析caller输出的时间。您需要知道或计算您的本地呼叫深度才能正确。从另一个函数或脚本中获取脚本等情况会导致数组（堆栈）更深。（FUNCNAME是一个特殊的 bash 数组变量，它应该有对应于调用堆栈的连续索引，只要它从不unset。）

因此，您可以添加到脚本的开头：

function check()
{
    if [[ ${FUNCNAME[-1]} != "source" ]]   # bash 4.2+, use ${FUNCNAME[@]: -1} for older
    then
        printf "Usage: source %s\n" "$0"
        exit 1
    fi
}
check

当您获取 shell 脚本时，shebang行将被忽略。通过放入无效的 shebang，您可以提醒用户该脚本被错误地执行：

#!/bin/bash source-this-script
# ...

错误消息将是这样的：

/bin/bash: source-this-script: No such file or directory

（任意）参数名称已经提供了强有力的提示，但错误消息仍然不是 100% 清楚。source-this-script我们可以使用放置在您的某处的实用程序脚本来解决此问题PATH：

#!/bin/sh
echo >&2 "This script must be sourced, not executed${1:+: }${1:-!}"
exit 1

现在，错误消息将是这样的：

This script must be sourced, not executed: path/to/script.sh

与其他方法的比较

与其他答案相比，这种方法只需要对每个脚本进行最少的更改（并且有一个 shebang 行有助于在编辑器中检测文件类型并指定 shell 脚本方言，因此甚至有好处）。缺点是有点不清楚的错误消息，或者（一次性）添加了另一个 shell 脚本。

但是，它不会阻止通过 显式调用bash path/to/script.sh（感谢@muru！）。

假设执行脚本只是无用而不是有害，您可以添加

return 0 || printf 'Must be sourced, not executed\n' >&2

到脚本的结尾。return除非正在获取文件，否则函数外部具有非零退出代码。

这是我编制的 4 种技术。如果脚本正在执行而不是sourced ，您可以以编程方式决定要做什么。

来自我的 eRCaGuy_hello_world 存储库中的check_if_sourced_or_executed.sh：

#!/usr/bin/env bash

main() {
    echo "Running main function."

    # put your code here

    echo -e "\nTOTAL TIME TO RUN main func:"
}

# Set the global variable `run` to "true" if the script is being executed and `main` should run, and
# set `run` to "false" otherwise--ex: if the script is being sourced in order to import functions
# from the script, but `main` should NOT run.
run_check() {
    # DEMONSTRATE A FEW DIFFERENT TECHNIQUES

    echo "Technique 1 (can be placed anywhere):"
    echo "  See: https://unix.stackexchange.com/a/424495/114401"
    if [ "${BASH_SOURCE[0]}" -ef "$0" ]; then
        echo "  This script is being EXECUTED."
        run="true"
    else
        echo "  This script is being SOURCED."
    fi


    echo "Technique 2 [MY 2ND FAVORITE] (can be placed anywhere):"
    echo "  Modified from: https://stackoverflow.com/a/29967433/4561887"
    if [ "${BASH_SOURCE[0]}" == "$0" ]; then
        echo "  This script is being EXECUTED."
        run="true"
    else
        echo "  This script is being SOURCED."
    fi

    echo "Technique 3 (requires another line which MUST be **outside** all functions):"
    echo "  Modified from: https://stackoverflow.com/a/28776166/4561887"
    if [ "$script_is_being_executed" == "true" ]; then
        echo "  This script is being EXECUTED."
        run="true"
    else
        echo "  This script is being SOURCED."
    fi


    echo "Technique 4 [MY 1ST FAVORITE] (MUST be **inside** a function):"
    echo "  Modified from: https://stackoverflow.com/a/14706745/4561887"
    echo "  and https://unix.stackexchange.com/a/424552/114401"
    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

}

# ==================================================================================================
# Main program entry point
# ==================================================================================================

# Only run main function if this file is being executed, NOT sourced.

# For Technique 3. This `return` statement MUST be called at a top-level scope, outside of all
# functions, in order to work! See their detailed explanation here for how it works:
# https://stackoverflow.com/a/28776166/4561887
(return 0 2>/dev/null) && script_is_being_executed="false" || script_is_being_executed="true"

run="false"
run_check
if [ "$run" == "true" ]; then
    time main "$@"
fi

测试运行命令：

# 1. Execute the script in 2 ways:
#   A. As an executable script
./bash/check_if_sourced_or_executed.sh
#   B. By calling the bash interpreter
bash ./bash/check_if_sourced_or_executed.sh

# 2. Source the script in 2 ways:
#   A. Bash source call
source ./bash/check_if_sourced_or_executed.sh
#   B. (Recommended) POSIX-compliant source call
. ./bash/check_if_sourced_or_executed.sh

另请参阅我在此处描述 Stack Overflow 上的 4 种技术：https ://stackoverflow.com/questions/2683279/how-to-detect-if-a-script-is-being-sourced/70662049#70662049