php man page for df

DF(1)								   User Commands							     DF(1)

NAME
       df - report file system disk space usage

SYNOPSIS
       df [OPTION]... [FILE]...

DESCRIPTION
       This  manual  page documents the GNU version of df.  df displays the amount of disk space available on the file system containing each file
       name argument.  If no file name is given, the space available on all currently mounted file systems is shown.  Disk space is  shown  in	1K
       blocks by default, unless the environment variable POSIXLY_CORRECT is set, in which case 512-byte blocks are used.

       If  an argument is the absolute file name of a disk device node containing a mounted file system, df shows the space available on that file
       system rather than on the file system containing the device node.  This version of df cannot show the space  available  on  unmounted  file
       systems, because on most kinds of systems doing so requires very nonportable intimate knowledge of file system structures.

OPTIONS
       Show information about the file system on which each FILE resides, or all file systems by default.

       Mandatory arguments to long options are mandatory for short options too.

       -a, --all
	      include pseudo, duplicate, inaccessible file systems

       -B, --block-size=SIZE
	      scale sizes by SIZE before printing them; e.g., '-BM' prints sizes in units of 1,048,576 bytes; see SIZE format below

       -h, --human-readable
	      print sizes in powers of 1024 (e.g., 1023M)

       -H, --si
	      print sizes in powers of 1000 (e.g., 1.1G)

       -i, --inodes
	      list inode information instead of block usage

       -k     like --block-size=1K

       -l, --local
	      limit listing to local file systems

       --no-sync
	      do not invoke sync before getting usage info (default)

       --output[=FIELD_LIST]
	      use the output format defined by FIELD_LIST, or print all fields if FIELD_LIST is omitted.

       -P, --portability
	      use the POSIX output format

       --sync invoke sync before getting usage info

       --total
	      elide all entries insignificant to available space, and produce a grand total

       -t, --type=TYPE
	      limit listing to file systems of type TYPE

       -T, --print-type
	      print file system type

       -x, --exclude-type=TYPE
	      limit listing to file systems not of type TYPE

       -v     (ignored)

       --help display this help and exit

       --version
	      output version information and exit

       Display	values	are  in  units	of the first available SIZE from --block-size, and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment
       variables.  Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).

       The SIZE argument is an integer and optional unit (example: 10K is 10*1024).  Units are K,M,G,T,P,E,Z,Y (powers of 1024) or KB,MB,... (pow-
       ers of 1000).

       FIELD_LIST  is  a  comma-separated list of columns to be included.  Valid field names are: 'source', 'fstype', 'itotal', 'iused', 'iavail',
       'ipcent', 'size', 'used', 'avail', 'pcent', 'file' and 'target' (see info page).

AUTHOR
       Written by Torbjorn Granlund, David MacKenzie, and Paul Eggert.

REPORTING BUGS
       GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
       Report df translation bugs to <http://translationproject.org/team/>

COPYRIGHT
       Copyright (C) 2017 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO
       Full documentation at: <http://www.gnu.org/software/coreutils/df>
       or available locally via: info '(coreutils) df invocation'

GNU coreutils 8.28						   January 2018 							     DF(1)