我可以做在bash下面的命令的返回值:獲取執行使用反引號在Perl
output=`command`
retcode=$?
有沒有辦法做同樣在Perl?像這樣:
$output=`command`
$retcode=???
我可以做在bash下面的命令的返回值:獲取執行使用反引號在Perl
output=`command`
retcode=$?
有沒有辦法做同樣在Perl?像這樣:
$output=`command`
$retcode=???
您可以閱讀$?
變量(如在shell中)。從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".
而且因爲Perl 5.10,你也有${^CHILD_ERROR_NATIVE}
。
從http://perldoc.perl.org/perl5100delta.html#New-internal-variables:
${^CHILD_ERROR_NATIVE}
這個變量給出了最後的管道關閉返回的原生狀態, 反引號命令,成功調用wait()或waitpid函數(),或從 system()運算符。詳情請參閱perlvar。
當你嘗試時發生了什麼? :-)認真地說,只是嘗試這樣的事情會比在這裏提出問題要快得多。 –