truncate - phpMan

File: coreutils.info,  Node: truncate invocation,  Prev: sync invocation,  Up: Disk usage
14.5 `truncate': Shrink or extend the size of a file
====================================================
`truncate' shrinks or extends the size of each FILE to the specified
size. Synopsis:
     truncate OPTION... FILE...
   Any FILE that does not exist is created.
   If a FILE is larger than the specified size, the extra data is lost.
If a FILE is shorter, it is extended and the extended part (or hole)
reads as zero bytes.
   The program accepts the following options.  Also see *note Common
options::.
`-c'
`--no-create'
     Do not create files that do not exist.
`-o'
`--io-blocks'
     Treat SIZE as number of I/O blocks of the FILE rather than bytes.
`-r RFILE'
`--reference=RFILE'
     Set the size of each FILE to the same size as RFILE.
`-s SIZE'
`--size=SIZE'
     Set the size of each FILE to this SIZE.  SIZE may be, or may be an
     integer optionally followed by, one of the following
     multiplicative suffixes:
          `KB' =>           1000 (KiloBytes)
          `K'  =>           1024 (KibiBytes)
          `MB' =>      1000*1000 (MegaBytes)
          `M'  =>      1024*1024 (MebiBytes)
          `GB' => 1000*1000*1000 (GigaBytes)
          `G'  => 1024*1024*1024 (GibiBytes)
     and so on for `T', `P', `E', `Z', and `Y'.
     SIZE may also be prefixed by one of the following to adjust the
     size of each FILE based on their current size:
          `+'  => extend by
          `-'  => reduce by
          `<'  => at most
          `>'  => at least
          `/'  => round down to multiple of
          `%'  => round up to multiple of

   An exit status of zero indicates success, and a nonzero value
indicates failure.