在连接 (.) 或字符串中使用未初始化的值 $a

Question

如果通过 SSH 计数超过 3 个，我将尝试删除目录中的旧文件

请提出解决问题的建议。

请参考代码片段

#!/usr/bin/perl
use strict;
use warnings;

my $HOME="/opt/app/latest";
my $LIBS="${HOME}/libs";
my $LIBS_BACKUP_DIR="${HOME}/libs_backups";
my $a;
my $b;
my $c;
my $d;

my $command =qq(sudo /bin/su - jenkins -c "ssh username\@server 'my $a=ls ${LIBS_BACKUP_DIR} | wc -l;my $b=`$a`;if ($b > 3); { print " Found More than 3 back up files , removing older files..";my $c=ls -tr ${LIBS_BACKUP_DIR} | head -1;my $d=`$c`;print "Old file name $d";}else { print "No of back up files are less then 3 .";} '");

print "$command\n";
system($command);

输出：

sudo /bin/su - jenkins -c "ssh username@server 'my ; =ls /opt/app/latest/libs_backups | wc -l;my ; =``;if ( > 3); { print " Found More than 3 back up files , removing older files..";my ; =ls -tr /opt/app/latest/libs_backups | head -1;my ; =``;print "Old file name ";}else { print "No of back up files are less then 3 .";} '"
Found: -c: line 0: unexpected EOF while looking for matching `''
Found: -c: line 1: syntax error: unexpected end of file

Answer 1

如果你有三级转义，手动转义肯定会出错。请改用 String::ShellQuote 的 shell_quote。

此外，避免生成代码。你一定会弄错的！使用参数、环境或其他一些通信渠道来传递必要的信息。

除了您试图在没有实际调用 perl!

的情况下执行 Perl 脚本之外，内部 Perl 脚本中还有许多错误

#!/usr/bin/perl

use strict;
use warnings;

use String::ShellQuote qw( shell_quote );

my $HOME = "/opt/app/latest";
my $LIBS = "$HOME/libs";
my $LIBS_BACKUP_DIR = "$HOME/libs_backups";

my $perl_script = <<'__EOI__';
   use strict;
   use warnings;

   use String::ShellQuote qw( shell_quote );

   my ($LIBS_BACKUP_DIR) = @ARGV;

   my $cmd = shell_quote("ls", "-tr", "--", $LIBS_BACKUP_DIR);
   chomp( my @files =  `$cmd` );
   if (@files > 3) {
      print "Found more than 3 back up files. Removing older files...\n";
      print "$_\n" for @files;
   } else {
      print "Found three or fewer backup files.\n";
   }
__EOI__

my $remote_cmd = shell_quote("perl", "-e", $perl_script, "--", $LIBS_BACKUP_DIR);
my $ssh_cmd = shell_quote("ssh", 'username@server', "--", $remote_cmd);
my $local_cmd = shell_quote("sudo", "su", "-c", $ssh_ccmd);
system($local_cmd);

Answer 2

我创建了一个新文件并处理目录检查和删除逻辑，scp 文件到远程服务器并在远程服务器中执行，完成删除文件后。

#!/usr/bin/perl
use strict;
use warnings;
use File::Basename;
use File::Path;
use FindBin;
use File::Copy;

my $HOME="/opt/app/test/latest";
my $LIBS_BACKUP_DIR="${HOME}/libs_backups";

my $a="ls ${LIBS_BACKUP_DIR} | wc -l";
my $b=`$a`;
my $c="ls -tr ${LIBS_BACKUP_DIR} | head -1";
my $d=`$c`;
chomp($d);
print " count : $b\n";



if ($b > 3)
{
print " Found More than 3 back up files , removing older files..\n";
print "Old file name $d\n";
my $filepath="${LIBS_BACKUP_DIR}/$d";
rmtree $filepath;
}
else
 {
 print "No of back up files are less then 3 .\n";
 }

在连接 (.) 或字符串中使用未初始化的值 $a

Use of uninitialized value $a in concatenation (.) or string

regex

bash

shell

perl

perl-module