Shell Script - Dynamic Call Function

原始討論

回覆內容

原本的寫法

#!/bin/bash

AA()
{
	return 9
}

BB()
{

	xx=`AA`
	if [ $(xx) -eq 9 ]; then
		return 0
	else
		return 1
	fi

}


if [ ! $(BB) ]; then
	echo "Y"
else
	echo "N"
fi

改成下面的寫法

#!/usr/bin/env bash

AA()
{
	return 9
}

BB()
{

	if [ AA -eq 9 ]; then
		return 0
	else
		return 1
	fi

}


if [ !BB  ]; then
	echo "Y"
else
	echo "N"
fi

執行

$ help if

可以看到 help

if: if COMMANDS; then COMMANDS; [ elif COMMANDS; then COMMANDS; ]... [ else COMMANDS; ] fi
    Execute commands based on conditional.

    The `if COMMANDS' list is executed.  If its exit status is zero, then the
    `then COMMANDS' list is executed.  Otherwise, each `elif COMMANDS' list is
    executed in turn, and if its exit status is zero, the corresponding
    `then COMMANDS' list is executed and the if command completes.  Otherwise,
    the `else COMMANDS' list is executed, if present.  The exit status of the
    entire construct is the exit status of the last command executed, or zero
    if no condition tested true.

    Exit Status:
    Returns the status of the last command executed.

也可以執行

$ help test

觀看相關的help

接下來解釋一些概念