ls.1

压缩包中包含LINUX下多个命令的源码

.\"	$OpenBSD: ls.1,v 1.23 2000/03/24 21:41:08 aaron Exp $
.\"	$NetBSD: ls.1,v 1.14 1995/12/05 02:44:01 jtc Exp $
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.\"     @(#)ls.1	8.7 (Berkeley) 7/29/94
.\"
.Dd July 29, 1994
.Dt LS 1
.Os
.Sh NAME
.Nm ls
.Nd list directory contents
.Sh SYNOPSIS
.Nm ls
.Op Fl 1ACFLRSTWacdfgiklmnopqrstux
.Op Ar file ...
.Sh DESCRIPTION
For each operand that names a
.Ar file
of a type other than
directory,
.Nm
displays its name as well as any requested,
associated information.
For each operand that names a
.Ar file
of type directory,
.Nm
displays the names of files contained
within that directory, as well as any requested, associated
information.
.Pp
If no operands are given, the contents of the current
directory are displayed.
If more than one operand is given,
non-directory operands are displayed first; directory
and non-directory operands are sorted separately and in
lexicographical order.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl A
List all entries except for
.Dq \&.
and
.Dq \&.. .
Always set for the super-user.
.It Fl C
Force multi-column output; this is the default when output is to a terminal.
.It Fl F
Display a slash
.Pq Sq /
immediately after each pathname that is a directory,
an asterisk
.Pq Sq \&*
after each that is executable,
an at sign
.Pq Sq @
after each symbolic link,
a percent sign
.Pq Sq %
after each whiteout,
an equal sign
.Pq Sq =
after each socket,
and a vertical bar
.Pq Sq \&|
after each that is a FIFO.
.It Fl L
If argument is a symbolic link, list the file or directory the link references
rather than the link itself.
.It Fl R
Recursively list subdirectories encountered.
.It Fl S
Sort by size, largest file first.
.It Fl T
Display complete time information for the file, including
month, day, hour, minute, second, and year.
This option has no effect unless one of the long format
.Pq Fl l , Fl n
options is also specified.
.It Fl W
Display whiteouts when scanning directories.
.It Fl a
Include directory entries whose names begin with a
dot
.Pq Sq \&. .
.It Fl c
Use time file's status was last changed instead of last modification
time for sorting
.Pq Fl t
or printing
.Pq Fl l , Fl n .
.It Fl d
Directories are listed as plain files (not searched recursively) and
symbolic links in the argument list are not indirected through.
.It Fl f
Output is not sorted.
.It Fl g
Does nothing; kept for compatibility with older versions of
.Xr ls 1 .
.It Fl i
For each file, print its inode number.
.It Fl k
Modifies the
.Fl s
option, causing the sizes to be reported in kilobytes.
Overrides any value specified by the
.Ev BLOCKSIZE
environment variable.
.It Fl l
(The lowercase letter
.Dq ell. Ns )
List in long format (see below).
If the output is to a terminal, a total sum of all file
sizes is output on a line before the long listing.
.It Fl m
Stream output format; list files across the page, separated by commas.
.It Fl n
List in long format as in
.Fl l ,
but retain user and group IDs in a numeric format.
.It Fl o
Include the file flags in a long format
.Pq Fl l , Fl n
output.
.It Fl p
Display a slash
.Pq Sq \&/
immediately after each pathname that is a directory.
.It Fl q
Force printing of non-graphic characters in file names as
the character
.Dq ? ;
this is the default when output is to a terminal.
.It Fl r
Reverse the order of the sort to get reverse
lexicographical order or the smallest or oldest entries first.
.It Fl s
Display the number of file system blocks actually used by each file,
where partial units are rounded up to the next integer value.
Blocks are 512 bytes unless overridden by the
.Fl k
flag or
.Ev BLOCKSIZE
environment variable.
.It Fl t
Sort by time modified (most recently modified
first) before sorting the operands in lexicographical
order.
.It Fl u
Use file's last access time
instead of last modification time
for sorting
.Pq Fl t
or printing
.Pq Fl l , Fl n .
.It Fl x
Multi-column output sorted across the page rather than down the page.
.It Fl \&1
(The numeric digit
.Dq one. Ns )
Force output to be one entry per line.
This is the default when
output is not to a terminal.
.El
.Pp
The
.Fl 1 ,
.Fl C ,
.Fl l ,
and
.Fl n
options all override each other; the last one specified determines
the format used.
.Pp
The
.Fl c
and
.Fl u
options override each other; the last one specified determines
the file time used.
The
.Fl f
option overrides any occurrence of either.
.Pp
By default,
.Nm
lists one entry per line to standard
output; the exceptions are to terminals or when the
.Fl C
or
.Fl m
options are specified.
.Pp
File information is displayed with one or more
<blank>s separating the information associated with the
.Fl i ,
.Fl s ,
.Fl l ,
and
.Fl n
options.
.Ss The Long Format
If the
.Fl l
or
.Fl n
options are given, the following information
is displayed for each file:
mode,
number of links,
owner,
group,
size in bytes,
time of last modification
.Pq Dq mmm dd HH:MM ,
and the pathname.
In addition, for each directory whose contents are displayed, the first
line displayed is the total number of blocks used by the files in the
directory.
Blocks are 512 bytes unless overridden by the
.Fl k
option or
.Ev BLOCKSIZE
environment variable.
.Pp
If the owner or group name is not a known user or group name, respectively,
or the
.Fl n
option is given, the numeric ID is displayed.
.Pp
If the file is a character special or block special file,
the major and minor device numbers for the file are displayed
in the size field.
.Pp
If the
.Fl T
option is given, the time of last modification is displayed using the
format
.Dq mmm dd HH:MM:SS CCYY .
.Pp
If the file is a symbolic link, the pathname of the
linked-to file is preceded by
.Dq \-> .
.Pp
The file mode printed under the
.Fl l
or
.Fl n
options consists of the entry type, owner permissions, and group
permissions.
The entry type character describes the type of file, as follows:
.Pp
.Bl -tag -width 4n -offset indent -compact
.It Sy b
block special file
.It Sy c
character special file
.It Sy d
directory
.It Sy l
symbolic link
.It Sy s
socket link
.It Sy p
.Tn FIFO
.It Sy w
whiteout
.It Sy \-
regular file
.El
.Pp
The next three fields
are three characters each:
owner permissions,
group permissions, and
other permissions.
Each field has three character positions:
.Pp
.Bl -enum -offset indent -compact
.It
If
.Sy r ,
the file is readable; if
.Sy \- ,
it is not readable.
.It
If
.Sy w ,
the file is writable; if
.Sy \- ,
it is not writable.
.It
The first of the following that applies:
.Bl -tag -width 4n -offset indent
.It Sy S
If in the owner permissions, the file is not executable and
set-user-ID mode is set.
If in the group permissions, the file is not executable
and set-group-ID mode is set.
.It Sy s
If in the owner permissions, the file is executable
and set-user-ID mode is set.
If in the group permissions, the file is executable
and setgroup-ID mode is set.
.It Sy x
The file is executable or the directory is
searchable.
.It Sy \-
The file is neither readable, writable, executable,
nor set-user-ID, nor set-group-ID, nor sticky (see below).
.El
.Pp
These next two apply only to the third character in the last group
(other permissions):
.Bl -tag -width 4n -offset indent
.It Sy T
The sticky bit is set
(mode
.Li 1000 ) ,
but neither executable nor searchable (see
.Xr chmod 1
or
.Xr sticky 8 ) .
.It Sy t
The sticky bit is set (mode
.Li 1000 ) ,
and is searchable or executable
(see
.Xr chmod 1
or
.Xr sticky 8 ) .
.El
.El
.Pp
In addition, if the
.Fl o
option is specified, the file flags (see
.Xr chflags 1 )
are displayed as comma-separated strings in front of the file size,
abbreviated as follows:
.Pp
.Bl -tag -width 8n -offset indent -compact
.It \&-
no flags
.It uappnd
user append-only
.It uchg
user immutable
.It nodump
do not dump
.It opaque
opaque file
.It sappnd
system append-only
.It arch
archived
.It schg
system immutable
.El
.Pp
The
.Nm
utility exits 0 on success or >0 if an error occurred.
.Sh ENVIRONMENT
The following environment variables affect the execution of
.Nm ls :
.Bl -tag -width BLOCKSIZE
.It Ev BLOCKSIZE
If the environment variable
.Ev BLOCKSIZE
is set, and the
.Fl k
option is not specified, the block counts
(see
.Fl s )
will be displayed in units of that size block.
.It COLUMNS
If this variable contains a string representing a
decimal integer, it is used as the
column position width for displaying
multiple-text-column output.
The
.Nm
utility calculates how
many pathname text columns to display
based on the width provided
(see
.Fl C ) .
.It Ev TZ
The timezone to use when displaying dates.
See
.Xr environ 7
for more information.
.El
.Sh COMPATIBILITY
The group field is now automatically included in the long listing for
files in order to be compatible with the
.St -p1003.2
specification.
.Sh SEE ALSO
.Xr chflags 1 ,
.Xr chmod 1 ,
.Xr symlink 7 ,
.Xr sticky 8
.Sh HISTORY
An
.Nm
utility appeared in
.At v5 .
.Sh STANDARDS
The
.Nm
utility is expected to be a superset of the
.St -p1003.2
specification.