tldr/pages/common/pv.md

pv

Monitor the progress of data through a pipe. More information: https://manned.org/pv.

• Print the contents of the file and display a progress bar:

pv {{path/to/file}}

• Measure the speed and amount of data flow between pipes (--size is optional):

{{command1}} | pv {{[-s|--size]}} {{expected_amount_of_data_for_eta}} | {{command2}}

• Filter a file, see both progress and amount of output data:

pv {{[-cN|--cursor --name]}} in {{path/to/file.txt}} | grep {{pattern}} | pv {{[-cN|--cursor --name]}} out > {{path/to/filtered_file.txt}}

• Attach to an already running process and see its file reading progress:

pv {{[-d|--watchfd]}} {{PID}}

• Read an erroneous file, skip errors as dd conv=sync,noerror would:

pv {{[-EE|--skip-errors --skip-errors]}} {{path/to/faulty_media}} > {{path/to/image.img}}

• Stop reading after reading specified amount of data, rate limit to 1K/s:

pv {{[-L|--rate-limit]}} {{1K}} {{[-S|--stop-at-size]}} {{maximum_file_size_to_be_read}}

• Calculate hash (MD5, SHA1, SHA256, etc) of a large file and show progress:

pv {{path/to/file}} | {{sha256sum}}