0323预习笔记和直播笔记

4.1 df

 man df    查看df命令的详细解释    （q退出）

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 dummy 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

       --direct
              show statistics for a file instead of mount point

       --total
              produce a grand total

       -h, --human-readable
              print sizes in human readable format (e.g., 1K 234M 2G)

       -H, --si
              likewise, but use powers of 1000 not 1024

       -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

       -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).

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

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

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

COPYRIGHT
       Copyright © 2013 Free Software Foundation, Inc.  License GPLv3+: GNU GPL  ver‐
       sion 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
       The full documentation for df is maintained as a Texinfo manual.  If the  info
       and df programs are properly installed at your site, the command

              info coreutils 'df invocation'

       should give you access to the complete manual.

GNU coreutils 8.22                    June 2014                                 DF(1)