coreutils: stdbuf invocation

1 
1 23.5 ‘stdbuf’: Run a command with modified I/O stream buffering
1 ===============================================================
1 
1 ‘stdbuf’ allows one to modify the buffering operations of the three
1 standard I/O streams associated with a program.  Synopsis:
1 
1      stdbuf OPTION... COMMAND
1 
1    COMMAND must start with the name of a program that
1   1. uses the ISO C ‘FILE’ streams for input/output (note the programs
1      ‘dd’ and ‘cat’ don’t do that),
1 
1   2. does not adjust the buffering of its standard streams (note the
1      program ‘tee’ is not in this category).
1 
1    Any additional ARGs are passed as additional arguments to the
1 COMMAND.
1 
11    The program accepts the following options.  Also see ⇒Common
 options.
1 
1 ‘-i MODE’
1 ‘--input=MODE’
1      Adjust the standard input stream buffering.
1 
1 ‘-o MODE’
1 ‘--output=MODE’
1      Adjust the standard output stream buffering.
1 
1 ‘-e MODE’
1 ‘--error=MODE’
1      Adjust the standard error stream buffering.
1 
1    The MODE can be specified as follows:
1 
1 ‘L’
1      Set the stream to line buffered mode.  In this mode data is
1      coalesced until a newline is output or input is read from any
1      stream attached to a terminal device.  This option is invalid with
1      standard input.
1 
1 ‘0’
1      Disable buffering of the selected stream.  In this mode, data is
1      output immediately and only the amount of data requested is read
1      from input.  Note the difference in function for input and output.
1      Disabling buffering for input will not influence the responsiveness
1      or blocking behavior of the stream input functions.  For example
1      ‘fread’ will still block until ‘EOF’ or error, even if the
1      underlying ‘read’ returns less data than requested.
1 
1 ‘SIZE’
1      Specify the size of the buffer to use in fully buffered mode.  SIZE
1      may be, or may be an integer optionally followed by, one of the
1      following multiplicative suffixes:
1           ‘KB’ =>           1000 (KiloBytes)
1           ‘K’  =>           1024 (KibiBytes)
1           ‘MB’ =>      1000*1000 (MegaBytes)
1           ‘M’  =>      1024*1024 (MebiBytes)
1           ‘GB’ => 1000*1000*1000 (GigaBytes)
1           ‘G’  => 1024*1024*1024 (GibiBytes)
1      and so on for ‘T’, ‘P’, ‘E’, ‘Z’, and ‘Y’.
1 
1    ‘stdbuf’ is installed only on platforms that use the Executable and
1 Linkable Format (ELF) and support the ‘constructor’ attribute, so
1 portable scripts should not rely on its existence.
1 
1    Exit status:
1 
1      125 if ‘stdbuf’ itself fails
1      126 if COMMAND is found but cannot be invoked
1      127 if COMMAND cannot be found
1      the exit status of COMMAND otherwise
1