csh - CSH Group Existence Test with Value Test

Question

在 CSH 中，是否可以在同一个 if 子句中嵌套对变量是否存在的测试及其值的测试？

#!/bin/csh

# This seems to work...
if ( $?VAR ) then
    echo "VAR exists"        
    if ( $VAR == true ) then
        echo "VAR is true"
    endif
endif

# I want something more like this:
if (( $?VAR ) && ( $VAR == true )) then
    echo "VAR exists and is true"
endif

Answer 1

短路评估是C shell 不做的许多事情之一。您将不得不使用嵌套if语句或切换 shell。