bar
Display progress bars for data transfers.
TLDR
SYNOPSIS
bar [options] [file]
DESCRIPTION
bar (clpbar) copies a stream of data and prints a display on stderr showing the amount of data passed, the throughput, and the transfer time. It was originally developed to estimate transfer duration for large data movements through SSH/tar pipes.The tool is useful for monitoring long-running data transfers, such as disk imaging, large file copies, or data streaming operations where visual feedback is desired. When reading from a regular file, it extracts the total size on its own.For piped input where size is unknown, the -s option allows specifying the expected size manually. Without size information, bar displays bytes transferred and transfer rate without a percentage. Configuration defaults can be placed in /etc/clpbarrc, ~/.barrc, or ./.barrc.
PARAMETERS
-if, --in-file FILE
Read input from FILE (default: stdin).-of, --out-file FILE
Write output to FILE (default: stdout).-s, --size bytes
Expected data size for accurate percentage display.-c, --completed bytes
Bytes already copied (for resumed transfers).-bs, --buffer-size size
I/O buffer allocation size.-th, --throttle rate
Limit throughput to the specified rate.-i, --interval seconds
Display update frequency in seconds (default: 1).-ti, --title text
Set a custom title for the progress bar.-sw, --screen-width cols
Assume a fixed terminal width of cols characters.-db, -nb, --display-bar, --no-bar
Toggle the progress bar display.-dp, -np, --display-percent, --no-percent
Toggle the percentage display.-dth, -nth, --display-throughput, --no-throughput
Toggle the throughput display.-dt, -nt, --display-time, --no-time
Toggle the elapsed time / ETA display.-ds, -ns, --display-summary, --no-summary
Toggle the completion summary.-h, --help
Display help information.-v, --version
Display program version.
CAVEATS
The bar command name conflicts with various system utilities on different distributions. The more widely available pv (pipe viewer) provides similar functionality with broader adoption. Progress percentage requires knowing total size in advance. Performance impact is minimal but measurable on very high-speed transfers.
HISTORY
Various "bar" utilities have existed in Unix ecosystems for displaying transfer progress. The concept predates graphical interfaces, providing feedback for operations that would otherwise run silently. pv (pipe viewer) by Andrew Wood became the de facto standard for this purpose, first released in 2002, though simpler implementations under various names continue to exist.
