获取在Perl中使用backticks执行的命令的返回值
我可以在bash中执行以下操作:获取在Perl中使用backticks执行的命令的返回值,perl,command,return-code,Perl,Command,Return Code,我可以在bash中执行以下操作: output=`command` retcode=$? 在Perl中有没有同样的方法?大概是这样的: $output=`command` $retcode=??? 您可以读取$?变量(如在shell中)。从man perlvar $? The status returned by the last pipe close, backtick ("``") command, successful call to wait() or waitpid()
output=`command`
retcode=$?
在Perl中有没有同样的方法?大概是这样的:
$output=`command`
$retcode=???
您可以读取
$?
变量(如在shell中)。从man perlvar
$? The status returned by the last pipe close, backtick ("``") command, successful call to wait() or waitpid(), or from the
system() operator. This is just the 16-bit status word returned by the traditional Unix wait() system call (or else is made up
to look like it). Thus, the exit value of the subprocess is really ("$? >> 8"), and "$? & 127" gives which signal, if any, the
process died from, and "$? & 128" reports whether there was a core dump. (Mnemonic: similar to sh and ksh.)
Additionally, if the "h_errno" variable is supported in C, its value is returned via $? if any "gethost*()" function fails.
If you have installed a signal handler for "SIGCHLD", the value of $? will usually be wrong outside that handler.
Inside an "END" subroutine $? contains the value that is going to be given to "exit()". You can modify $? in an "END"
subroutine to change the exit status of your program. For example:
END {
$? = 1 if $? == 255; # die would make it 255
}
Under VMS, the pragma "use vmsish 'status'" makes $? reflect the actual VMS exit status, instead of the default emulation of
POSIX status; see "$?" in perlvms for details.
Also see "Error Indicators".
从Perl5.10开始,您还拥有
${^CHILD\u ERROR\u NATIVE}
发件人:
${^CHILD\u ERROR\u NATIVE}
此变量提供上次管道关闭返回的本机状态,
backtick命令,成功调用wait()或waitpid(),或从
system()运算符。有关详细信息,请参见perlvar
您尝试时发生了什么?:-)说真的,尝试这样的事情比在这里提问要快得多。