Tcl “为什么？”；执行官；给予；“儿童异常退出”；在这个代码中？

我在tcl中运行以下代码：-

set version [exec grep "INTERNAL VERSION:" mojave.log | sed -n -e "s/INTERNAL VERSION: //g" > xor.diff]

set p [exec diff ../log.warning.diff ../log.warning.gold >> xor.diff ]

对于最后一行，在进行一些区分之后，它给出了以下错误：-

> RULE-311 WARNING: Gdsii layer number 85 datatype 0 has already been defined
> TCL-11   WARNING: Command "check quartz drc" is overridden, Quality Of
> TCL-11   WARNING: Command "delete marker quartz" is overridden, Quality Of
> TCL-11   WARNING: Command "import marker quartz" is overridden, Quality Of
> TCL-11   WARNING: Command "mojave! run filter log" is overridden, Quality Of
> TCL-11   WARNING: Command "run quartz gui" is overridden, Quality Of Results
> TCL-11   WARNING: Command "ui! mojave draw rectangle" is overridden, Quality
> TCL-11   WARNING: Command "ui! mojave set_context" is overridden, Quality Of
> TCL-12   WARNING: Overridden command "mojave! run filter log" is used,
child process exited abnormally
     while executing
"exec diff ../log.warning.diff ../log.warning.gold 2> xor.diff "
     invoked from within
"set p [exec diff ../log.warning.diff ../log.warning.gold 2> xor.diff ]"
     (file "test.tcl" line 4)
     invoked from within
"source test.tcl"

它不会在“

xor.diff

”文件中写入任何内容。

diff

（和

comm

）如果发现任何差异，将退出非零状态，因此您可以重定向输出以将其用作“是否发生了此更改？”测试。对于Tcl，您需要使用“| |：：”习惯用法来忽略退出状态

---

附言“grep的无用使用”

sed-n-e'/内部版本：/s//gp'

exec

如果命令返回非零或向stderr发送任何内容，则返回错误。如果我们将“exec”命令写在“catch”中，我们将非常深入地讨论如何将

catch

与

exec

at

一起使用。感谢您的帮助。+1表示“无用的grep使用”；使我免于回答那样的问题