Question

我有一个csh脚本需要使用newgrp来运行它的一部分。为此，它递归地调用自己。

#!/bin/csh
if ( $1 == "" ) then
    newgrp << ENDGRP
    ./newgrp_test.csh 2
    if ( $status != 0 ) then
        echo "Second run fail"
        exit 1
    else
        echo "Second run success"
        exit 0
    endif
ENDGRP
    if ( $status != 0) then
        echo "Exiting failure"
        exit 1
    else
        echo "Exiting success"
        exit 0
    endif
endif

if ( $1 == "2" ) then
    exit 1
endif

问题是我认为应该保证失败，但我得到了成功的输出。我的输出如下：

Second run success
Exiting success

为什么我不能在newgrp中读取脚本的状态？

注意我已经通过删除newgrp和ENDGRP之间的if块找到了解决方法，但我仍然很好奇。

Answer 1

The variable $status is being expanded by the outer shell inside the here document. So when the newgrp-spawned shell runs it is seeing if ( 0 != 0 ) then and not if ( $status != 0 ) then (because the if, or whateverwas successful immediately before thenewgrp` command).

You either need to escape the $ in the here document:

if ( \$status != 0 ) then

or quote part of the here document word to prevent expansion from happening entirely:

    newgrp << 'ENDGRP'
    ./newgrp_test.csh 2
    if ( $status != 0 ) then
        echo "Second run fail"
        exit 1
    else
        echo "Second run success"
        exit 0
    endif
'ENDGRP'

如何查看newgrp中调用的命令的状态？

1 个答案: