Provided by: pv_1.6.6-1_amd64 bug


       pv - monitor the progress of data through a pipe


       pv [OPTION] [FILE]...
       pv [-h|-V]


       pv  shows  the  progress  of  data  through  a pipeline by giving information such as time
       elapsed, percentage completed (with progress bar), current  throughput  rate,  total  data
       transferred, and ETA.

       To  use  it,  insert it in a pipeline between two processes, with the appropriate options.
       Its standard input will be passed through to its standard  output  and  progress  will  be
       shown on standard error.

       pv will copy each supplied FILE in turn to standard output (- means standard input), or if
       no FILEs are specified just standard input is  copied.  This  is  the  same  behaviour  as

       A simple example to watch how quickly a file is transferred using nc(1):

              pv file | nc -w 1 3000

       A  similar example, transferring a file from another process and passing the expected size
       to pv:

              cat file | pv -s 12345 | nc -w 1 3000

       A more complicated example using numeric output to feed into the dialog(1) program  for  a
       full-screen progress display:

              (tar cf - . \
               | pv -n -s $(du -sb . | awk '{print $1}') \
               | gzip -9 > out.tgz) 2>&1 \
              | dialog --gauge 'Progress' 7 70

       Taking an image of a disk, skipping errors:

              pv -EE /dev/sda > disk-image.img

       Writing an image back to a disk:

              pv disk-image.img > /dev/sda

       Zeroing a disk:

              pv < /dev/zero > /dev/sda

       Note  that  if the input size cannot be calculated, and the output is a block device, then
       the size of the block device will be used and pv will automatically stop at that  size  as
       if -S had been given.

       (Linux only): Watching file descriptor 3 opened by another process 1234:

              pv -d 1234:3

       (Linux only): Watching all file descriptors used by process 1234:

              pv -d 1234


       pv  takes  many  options,  which  are divided into display switches, output modifiers, and
       general options.


       If no display switches are specified, pv behaves as if -p, -t, -e, -r,  and  -b  had  been
       given (i.e. everything except average rate is switched on).  Otherwise, only those display
       types that are explicitly switched on will be shown.

       -p, --progress
              Turn the progress bar on.  If standard input is not a file and no  size  was  given
              (with  the  -s  modifier), the progress bar cannot indicate how close to completion
              the transfer is, so it will just move left and  right  to  indicate  that  data  is

       -t, --timer
              Turn  the  timer  on.   This  will  display the total elapsed time that pv has been
              running for.

       -e, --eta
              Turn the ETA timer on.  This will attempt to  guess,  based  on  previous  transfer
              rates  and the total data size, how long it will be before completion.  This option
              will have no effect if the total data size cannot be determined.

       -I, --fineta
              Turn the ETA timer on, but display the estimated local time of arrival  instead  of
              time left.  When the estimated time is more than 6 hours in the future, the date is
              shown as well.

       -r, --rate
              Turn the rate counter on.  This will display the current rate of data transfer.

       -a, --average-rate
              Turn the average rate counter on.  This will  display  the  average  rate  of  data
              transfer so far.

       -b, --bytes
              Turn  the  total  byte  counter  on.   This  will  display the total amount of data
              transferred so far.

       -T, --buffer-percent
              Turn on the transfer buffer percentage display.  This will show the  percentage  of
              the  transfer buffer in use - but see the caveat under %T in the FORMATTING section

       -A, --last-written NUM
              Show the last NUM bytes written - but see the caveat under %nA  in  the  FORMATTING
              section below.

       -F, --format FORMAT
              Ignore  the  options -p, -t, -e, -r, -a, -b, -T, and -A, and instead use the format
              string FORMAT to determine the output format.  See the FORMATTING section below.

       -n, --numeric
              Numeric output.  Instead of giving a visual indication of progress, pv will give an
              integer  percentage,  one  per  line,  on  standard error, suitable for piping (via
              convoluted redirection) into dialog(1).  Note that -f is  not  required  if  -n  is
              being used.

              Note  that  if  --numeric  is  in use, then adding --bytes will cause the number of
              bytes processed so far to be output instead of a percentage; if --line-mode is also
              in  use,  then  instead  of  bytes  or  a percentage, the number of lines so far is
              output.  And finally, if --timer is also in use, then each output line is  prefixed
              with the elapsed time so far, as a decimal number of seconds.

       -q, --quiet
              No  output.   Useful  if  the  -L option is being used on its own to just limit the
              transfer rate of a pipe.


       -W, --wait
              Wait until the  first  byte  has  been  transferred  before  showing  any  progress
              information  or  calculating  any ETAs.  Useful if the program you are piping to or
              from requires extra information before it starts, eg piping  data  into  gpg(1)  or
              mcrypt(1) which require a passphrase before data can be processed.

       -D, --delay-start SEC
              Wait  until  SEC  seconds  have passed before showing any progress information, for
              example in a script where you only want to show a progress bar if it starts  taking
              a long time.  Note that this can be a decimal such as 0.5.

       -s SIZE, --size SIZE
              Assume  the  total  amount of data to be transferred is SIZE bytes when calculating
              percentages and ETAs.  The same suffixes of "k", "m" etc can be used as with -L.

              Has no effect if used with -d PID to watch all file descriptors of a  process,  but
              will work with -d PID:FD.

       -l, --line-mode
              Instead  of counting bytes, count lines (newline characters). The progress bar will
              only move when a new line is found, and the value passed to the -s option  will  be
              interpreted as a line count.  Note that file sizes are not automatically calculated
              when this option is used, to avoid having to read all files twice.

       -0, --null
              Count lines as null terminated.  This option implies --line-mode.

       -i SEC, --interval SEC
              Wait SEC seconds between updates.  The default is to  update  every  second.   Note
              that this can be a decimal such as 0.1.

       -w WIDTH, --width WIDTH
              Assume  the terminal is WIDTH characters wide, instead of trying to work it out (or
              assuming 80 if it cannot be guessed).

       -H HEIGHT, --height HEIGHT
              Assume the terminal is HEIGHT rows high, instead of  trying  to  work  it  out  (or
              assuming 25 if it cannot be guessed).

       -N NAME, --name NAME
              Prefix the output information with NAME.  Useful in conjunction with -c if you have
              a complicated pipeline and you want to be able to tell different parts of it apart.

       -f, --force
              Force output.  Normally, pv will not output any visual display if standard error is
              not a terminal.  This option forces it to do so.

       -c, --cursor
              Use  cursor  positioning  escape  sequences instead of just using carriage returns.
              This is useful in  conjunction  with  -N  (name)  if  you  are  using  multiple  pv
              invocations in a single, long, pipeline.


       -L RATE, --rate-limit RATE
              Limit  the  transfer  to a maximum of RATE bytes per second.  A suffix of "K", "M",
              "G", or "T" can be added to denote kibibytes (*1024), mebibytes, and so on.

       -B BYTES, --buffer-size BYTES
              Use a transfer buffer size of BYTES bytes.  A suffix of "K", "M", "G", or  "T"  can
              be  added  to  denote  kibibytes (*1024), mebibytes, and so on.  The default buffer
              size is the block size of the input file's  filesystem  multiplied  by  32  (512KiB
              max), or 400KiB if the block size cannot be determined.

       -C, --no-splice
              Never  use  splice(2), even if it would normally be possible.  The splice(2) system
              call is a more efficient way of transferring data from or to a  pipe  than  regular
              read(2)  and  write(2),  but  means that the transfer buffer may not be used.  This
              prevents -A and -T from working, so if you want to use -A or -T then you will  need
              to use -C, at the cost of a small loss in transfer efficiency.  (This option has no
              effect on systems where splice(2) is unavailable).

       -E, --skip-errors
              Ignore read errors  by  attempting  to  skip  past  the  offending  sections.   The
              corresponding  parts  of  the output will be null bytes.  At first only a few bytes
              will be skipped, but if there are many errors in a row then the skips will move  up
              to  chunks  of 512.  This is intended to be similar to dd conv=sync,noerror but has
              not been as thoroughly tested.

              Specify -E twice to only report a read error once per file,  instead  of  reporting
              each byte range skipped.

       -S, --stop-at-size
              If  a  size was specified with -s, stop transferring data once that many bytes have
              been written, instead of continuing to the end of input.

       -d PID[:FD], --watchfd PID[:FD]
              Instead of transferring data, watch file descriptor FD of process PID, and show its
              progress.   The  pv  process  will exit when FD either changes to a different file,
              changes read/write mode, or is closed; other data transfer modifiers -  and  remote
              control - may not be used with this option.

              If  only  a  PID  is  specified, then that process will be watched, and all regular
              files and block devices it opens will be shown with a progress bar.  The pv process
              will exit when process PID exits.

       -R PID, --remote PID
              If  PID  is  an  instance  of  pv  that  is already running, -R PID will cause that
              instance to act as though it had been given this instance's command  line  instead.
              For example, if pv -L 123K is running with process ID 9876, then running pv -R 9876
              -L 321K will cause it to start using a rate limit  of  321KiB  instead  of  123KiB.
              Note that some options cannot be changed while running, such as -c, -l, -f, -D, -E,
              and -S.


       -P FILE, --pidfile FILE
              Save the process ID of pv in FILE.  The  file  will  be  truncated  if  it  already
              exists,  and will be removed when pv exits.  While pv is running, it will contain a
              single number - the process ID of pv - followed by a newline.

       -h, --help
              Print a usage message on standard output and exit successfully.

       -V, --version
              Print version information on standard output and exit successfully.


       If the -F option is given, then the output  format  is  determined  by  the  given  format
       string.  Within that string, the following sequences can be used:

       %p     Progress  bar.  Expands to fill the remaining space. Should only be specified once.
              Equivalent to -p.

       %t     Elapsed time.  Equivalent to -t.

       %e     ETA as time remaining.  Equivalent to -e.

       %I     ETA as local time of completion.  Equivalent to -I.

       %r     Current data transfer rate.  Equivalent to -r.

       %a     Average data transfer rate.  Equivalent to -a.

       %b     Bytes transferred so far (or lines if -l was specified).  Equivalent to -b.

       %T     Percentage of the transfer buffer in use.  Equivalent to -T.  Shows "{----}" if the
              transfer is being done with splice(2), since splicing to or from pipes does not use
              the buffer.

       %nA    Show the last n bytes written (e.g.  %16A for the last 16 bytes).  Shows only  dots
              if  the transfer is being done with splice(2), since splicing to or from pipes does
              not use the buffer.

       %N     Name prefix given by -N.  Padded to 9 characters with spaces, and suffixed with :.

       %%     A single %.

       The format string equivalent of turning on all display switches is `%N %b %T %t %r  %a  %p


       Some suggested common switch combinations:

       pv -ptebar
              Show a progress bar, elapsed time, estimated completion time, byte counter, average
              rate, and current rate.

       pv -betlap
              Show a progress bar, elapsed time, estimated completion  time,  line  counter,  and
              average rate, counting lines instead of bytes.

       pv -t  Show only the elapsed time - useful as a simple timer, e.g.  sleep 10m | pv -t.

       pv -pterb
              The  default  behaviour:  progress  bar,  elapsed  time, estimated completion time,
              current rate, and byte counter.


       An exit status of 1 indicates a problem with the -R or -P options.

       Any other exit status is a bitmask of the following:

       2      One or more files could not be accessed, stat(2)ed, or opened.

       4      An input file was the same as the output file.

       8      Internal error with closing a file or moving to the next file.

       16     There was an error while transferring data from one or more input files.

       32     A signal was caught that caused an early exit.

       64     Memory allocation failed.

              A zero exit status indicates no problems.


       Written by Andrew Wood, with patches submitted by various other people.   Please  see  the
       package README for a complete list of contributors.


       The following problems are known to exist in pv:

       *      The  -c  option  does  not  work  properly  on Cygwin without cygserver running, if
              started near the bottom of the  screen  (IPC  is  needed  to  handle  the  terminal
              scrolling).  To fix this, start cygserver before using pv -c.

       *      The  -R  option  is  not available on Cygwin without cygserver running (SYSV IPC is
              needed). To fix this, start cygserver before running the instance of pv  you  want,
              at runtime, to change the parameters of.

       If you find any other problems, please report them.


       Report  bugs  in pv to or use the contact form linked from the pv home page:


       cat(1), dialog(1), splice(2)


       This is free software, distributed under the ARTISTIC 2.0 license.