linux shell中如何接收程序返回值

Posted 2023-04-09

参考技术A $?
$?就是表示上一次脚本或者命令退出时的返回值。通常，0代表成功；非0代表出现错误。
类似的一些符号如$0 $1 $2 $@ $# 。

Before we move on, there is a perversity about tests in Bash shells that I want to discuss. It turns out, because of a historical accident that now might as well be cast in concrete, when a test is conducted or a command returns a result value, the numerical value for "true" is 0, and "false" is 1. Those of you who have some programming experience will likely find this reversal of intuition as annoying as I do.

Here is a way to get the result of the most recent logical test (and to show the weird reversal described above):

$ test -e .
$ echo $?
0

$ test -e xyz
$ echo $?
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linux shell中获得进程返回值

linux shell中获得进程返回值

我在shell中执行了一个程序，如何获取这个程序的返回值呢，我记得可以获取的，忘记怎么做了。。。。

参考技术A 我也记得不是很清楚，$?表示上一次的命令正确的话返回0.不正确返回非0数。 参考技术B echo $?追问

应该不是 echo $ 这个符号吧？ 无法输出返回值

追答

shell中 $? 是上一个进程的返回值，用echo命令将其输出即可。是 echo $?，不是echo $。

本回答被提问者采纳