## 命令执行进度 ``` PV ("Pipe Viewer") is a tool for monitoring the progress of data through a pipeline. It can be inserted into any normal pipeline between two processes to give a visual indication of how quickly data is passing through, how long it has taken, how near to completion it is, and an estimate of how long it will be until completion. ``` 显示当前在命令行执行的命令的进度信息，管道查看器。 ## 补充说明 **pv命令**Pipe Viewer 的简称，由Andrew Wood 开发。意思是通过管道显示数据处理进度的信息。这些信息包括已经耗费的时间，完成的百分比(通过进度条显示)，当前的速度，全部传输的数据，以及估计剩余的时间。 ## 下载安装 ~~~bash # Debian 系的操作系统，如 Ubuntu sudo apt-get install pv # RedHat系的则这样： yum install pv ~~~ ### 语法 ~~~bash pv(选项)(参数) pv [OPTION] [FILE]... ~~~ ### 选项 ~~~ -p, --progress show progress bar -t, --timer show elapsed time -e, --eta show estimated time of arrival (completion) -I, --fineta show absolute estimated time of arrival (completion) -r, --rate show data transfer rate counter -a, --average-rate show data transfer average rate counter -b, --bytes show number of bytes transferred -T, --buffer-percent show percentage of transfer buffer in use -A, --last-written NUM show NUM bytes last written -F, --format FORMAT set output format to FORMAT -n, --numeric 输出百分比 -q, --quiet do not output any transfer information at all -W, --wait display nothing until first byte transferred -D, --delay-start SEC display nothing until SEC seconds have passed -s, --size SIZE set estimated data size to SIZE bytes -l, --line-mode count lines instead of bytes -0, --null lines are null-terminated -i, --interval SEC update every SEC seconds -w, --width WIDTH assume terminal is WIDTH characters wide -H, --height HEIGHT assume terminal is HEIGHT rows high -N, --name NAME prefix visual information with NAME -f, --force output even if standard error is not a terminal -c, --cursor use cursor positioning escape sequences -L, --rate-limit RATE limit transfer to RATE bytes per second -B, --buffer-size BYTES use a buffer size of BYTES -C, --no-splice never use splice(), always use read/write -E, --skip-errors skip read errors in input -S, --stop-at-size stop after --size bytes have been transferred -R, --remote PID update settings of process PID -P, --pidfile FILE save process ID in FILE -d, --watchfd PID[:FD] watch file FD opened by process PID -h, --help 显示帮助 -V, --version 显示版本信息 ~~~ ### 实例 我们（在 linux 上使用命令行的用户）的大多数使用场景都会用到的命令是从一个 USB 驱动器拷贝电影文件到你的电脑。如果你使用 cp 来完成上面的任务，你会什么情况都不清楚，直到整个复制过程结束或者出错。 ~~~bash # 复制文件会有进度 # pv ~/Downloads/CentOS-7-x86_64-Minimal-1511.iso > ~/Desktop/CentOS-7-x86_64-Minimal-1511.iso # 下面输入信息 552MiB 0:00:02 [ 212MiB/s] [==================> ] 91% ETA 0:00:00 # -L 可以让你修改 pv 命令的传输速率。 # 使用 -L 选项来限制传输速率为2MB/s。 pv -L 2m /media/himanshu/1AC2-A8E3/fNf.mkv > ./Desktop/fnf.mkv ~~~ ~~~bash # 字符一个个匀速在命令行中显示出来 echo "Tecmint[dot]com is a community of Linux Nerds and Geeks" | pv -qL 10 # 压缩文件展示进度信息 pv /media/himanshu/1AC2-A8E3/fnf.mkv | gzip > ./Desktop/fnf.log.gz ~~~ ## 测试网速 ~~~ # 服务端 cat /dev/zero | pv | nc -l -p 2222 # 客户端 nc localhost 2222 | pv ~~~