Question

是否有可能在没有调用函数main的情况下调用函数_end_win？

#!/usr/bin/env perl
use warnings;
use strict;
use 5.10.0;
use Term::ReadKey;

use constant {
    NEXT_getch      => -1,
    CONTROL_C       => 0x03,
    CONTROL_D       => 0x04,
    KEY_ENTER       => 0x0d,
    KEY_RIGHT       => 0x1b5b43,
    KEY_LEFT        => 0x1b5b44,
};


say main();

sub main {
    my $arg = {};
    $arg->{handle_out} = *STDOUT;
    _init_scr( $arg );
    while ( 1 ) {
        my $c = _getch( $arg );
        if ( ! defined $c ) {
            _end_win( $arg );
            warn "EOT";
            return;
        }
        next if $c == NEXT_getch;
        given ( $c ) {
            when ( $c >= 97 && $c <= 122 ) {
                print chr $c;
                $arg->{string} .= chr $c;
            }
            when ( $c == KEY_RIGHT ) {
                print '>';
                $arg->{string} .= '>';
            }
            when ( $c == KEY_LEFT ) {
                print '<';
                $arg->{string} .= '<';
            }
            when ( $c == CONTROL_D ) {
                _end_win( $arg );
                return;
            }
            when ( $c == CONTROL_C ) {
                _end_win( $arg );
                print STDERR "^C";
                kill( 'INT', $$ );
                return;
            }
            when ( $c == KEY_ENTER ) {
                _end_win( $arg );
                return $arg->{string};
            }
        }
    }
}

sub _init_scr {
    my ( $arg ) = @_;
    $arg->{old_handle} = select( $arg->{handle_out} );
    $arg->{backup_flush} = $|;
    $| = 1;
    Term::ReadKey::ReadMode 'ultra-raw';
}

sub _end_win {
    my ( $arg ) = @_;
    print "\n\r";
    Term::ReadKey::ReadMode 'restore';
    $| = $arg->{backup_flush};
    select( $arg->{old_handle} );
}

sub _getch {
    my ( $arg ) = @_;
    my $c1 = ReadKey 0;
    return if ! defined $c1;
    if ( $c1 eq "\e" ) {
        my $c2 = ReadKey 0.10;
        if ( ! defined $c2 ) { return NEXT_getch; }
        elsif ( $c2 eq 'C' ) { return KEY_RIGHT; }
        elsif ( $c2 eq 'D' ) { return KEY_LEFT; }
        elsif ( $c2 eq '[' ) {
            my $c3 = ReadKey 0;
            if ( $c3 eq 'C' ) { return KEY_RIGHT; }
            elsif ( $c3 eq 'D' ) { return KEY_LEFT; }
            else {
                return NEXT_getch;
            }
        }
        else {
            return NEXT_getch;
        }
    }
    else {
        return ord $c1;
    }
}

Answer 1

要确保在程序退出时重置终端，请将重置代码放入END块。例如，您可以将_end_win子替换为：

END {
    print "\n\r";
    Term::ReadKey::ReadMode 'restore';
}

（我删除了重置$|和select ed输出文件句柄的行，因为无论如何退出流程，所以它们将变得无关紧要。）

当程序以“正常”方式终止时，END块将始终运行，例如调用exit或die或命中可执行代码的末尾。由于接收到信号，当过程终止时，它不会触发;看起来您正在直接处理ctrl-C字符，但您可能还需要考虑添加%SIG{INT}处理程序，以防有人向您发送kill -2。

再次建立初始状态的安全方式。

1 个答案: