我只是在运行一个tail -n1 command 2>/dev/null
,出于某种奇怪的原因,输出向我显示了两个不同的东西:
> masscan_progress
=> "rate: 0.00-kpps, 0.00% done,3586348854:03:28 remaining, found=0 \rrate: 3.49-kpps, 0.08% done, 2:07:20 remaining, found=3 \rrate: 3.48-kpps, 0.16% done, 1:02:57 remaining, found=6 \rrate: 3.49-kpps, 0.24% done, 0:42:18 remaining, found=10 \rrate: 3.49-kpps, 0.31% done, 0:31:58 remaining, found=14 \rrate: 3.49-kpps, 0.40% done, 0:24:59 remaining, found=20 \rrate: 3.49-kpps, 0.47% done, 0:21:15 remaining, found=23 \rrate: 3.49-kpps, 0.55% done, 0:18:05 remaining, found=30 \rrate: 3.48-kpps, 0.63% done, 0:15:53 remaining, found=35 \rrate: 3.49-kpps, 0.71% done, 0:15:50 remaining, found=36 \rrate: 3.49-kpps, 0.78% done, 0:15:58 remaining, found=40 \rrate: 3.48-kpps, 0.87% done, 0:15:44 remaining, found=42 \rrate: 3.49-kpps, 0.94% done, 0:15:52 remaining, found=42 \rrate: 3.48-kpps, 1.02% done, 0:15:54 remaining, found=48 \rrate: 3.48-kpps, 1.09% done, 0:15:53 remaining, found=50 \rrate: 3.47-kpps, 1.18% done, 0:15:43 remaining, found=52 \rrate: 3.48-kpps, 1.25% done, 0:15:52 remaining, found=57 \rrate: ...
但puts
返回的正是我要查找的内容:
> puts masscan_progress
rate: 3.47-kpps, 85.98% done, 0:02:15 remaining, found=3305
因此,从masscan_progress
变量中搜索数据的其他命令并没有看到我在puts
中看到的内容,而是看到了更大的输出。
事实上,我以前从来没有见过这种情况,也不太确定为什么会发生这种情况。如有任何建议,我们将不胜感激。
1条答案
按热度按时间toiithl61#
"r"
(表示单个carriage return字符的转义)告诉终端返回到同一行的开头;之后的输出将覆盖之前在该行上写入的内容。