Category Archives: Linux Man Pages


SORT(1) User Commands SORT(1)

sort – sort lines of text files

sort [OPTION]… [FILE]…

Write sorted concatenation of all FILE(s) to standard output.

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

-b, –ignore-leading-blanks
ignore leading blanks

-d, –dictionary-order
consider only blanks and alphanumeric characters

-f, –ignore-case
fold lower case to upper case characters

-g, –general-numeric-sort
compare according to general numerical value

-i, –ignore-nonprinting
consider only printable characters

-M, –month-sort
compare (unknown) < `JAN’ < … < `DEC’

-n, –numeric-sort
compare according to string numerical value

-R, –random-sort
sort by random hash of keys

get random bytes from FILE (default /dev/urandom)

sort according to WORD: general-numeric -g, month -M, numeric
-n, random -R

-r, –reverse
reverse the result of comparisons

Other options:

-c, –check, –check=diagnose-first
check for sorted input; do not sort

-C, –check=quiet, –check=silent
like -c, but do not report first bad line

compress temporaries with PROG; decompress them with PROG -d

-k, –key=POS1[,POS2]
start a key at POS1, end it at POS2 (origin 1)

-m, –merge
merge already sorted files; do not sort

-o, –output=FILE
write result to FILE instead of standard output

-s, –stable
stabilize sort by disabling last-resort comparison

-S, –buffer-size=SIZE
use SIZE for main memory buffer

-t, –field-separator=SEP
use SEP instead of non-blank to blank transition

-T, –temporary-directory=DIR
use DIR for temporaries, not $TMPDIR or /tmp; multiple options
specify multiple directories

-u, –unique
with -c, check for strict ordering; without -c, output only the
first of an equal run

-z, –zero-terminated
end lines with 0 byte, not newline

–help display this help and exit

output version information and exit

POS is F[.C][OPTS], where F is the field number and C the character
position in the field; both are origin 1. If neither -t nor -b is in
effect, characters in a field are counted from the beginning of the
preceding whitespace. OPTS is one or more single-letter ordering
options, which override global ordering options for that key. If no
key is given, use the entire line as the key.

SIZE may be followed by the following multiplicative suffixes: % 1% of
memory, b 1, K 1024 (default), and so on for M, G, T, P, E, Z, Y.

With no FILE, or when FILE is -, read standard input.

*** WARNING *** The locale specified by the environment affects sort
order. Set LC_ALL=C to get the traditional sort order that uses native
byte values.

Written by Mike Haertel and Paul Eggert.

Report bugs to <>.

Copyright © 2008 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

The full documentation for sort is maintained as a Texinfo manual. If
the info and sort programs are properly installed at your site, the

info coreutils ‘sort invocation’

should give you access to the complete manual.

GNU coreutils 6.12 December 2008 SORT(1)

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wvdial – PPP dialer with built-in intelligence.


wvdial –help | –version | –chat | –config | option=value | –no-
syslog | section…


wvdial is an intelligent PPP dialer, which means that it dials a modem
and starts PPP in order to connect to the Internet. It is something
like the chat(8) program, except that it uses heuristics to guess how
to dial and log into your server rather than forcing you to write a
login script.

When wvdial starts, it first loads its configuration from
/etc/wvdial.conf and ~/.wvdialrc which contains basic information about
the modem port, speed, and init string, along with information about
your Internet Service Provider (ISP), such as the phone number, your
username, and your password.

Then it initializes your modem and dials the server and waits for a
connection (a CONNECT string from the modem). It understands and
responds to typical connection problems (like BUSY and NO DIALTONE).

Any time after connecting, wvdial will start PPP if it sees a PPP
sequence from the server. Otherwise, it tries to convince the server
to start PPP by doing the following:

– responding to any login/password prompts it sees;

– interpreting “choose one of the following”-style menus;

– eventually, sending the word “ppp” (a common terminal server com-

If all of this fails, wvdial just runs pppd(8) and hopes for the best.
It will bring up the connection, and then wait patiently for you to
drop the link by pressin CTRL-C.


Several options are recognized by wvdial.

–chat Run wvdial as a chat replacement from within pppd, instead of
the more normal method of having wvdial negotiate the connection
and then call pppd.

Override the Remote Name setting in the dialer configuration
section of the configuration file. This is mainly useful when
you dial to multiple systems with the same user name and pass-
word, and you don’t want to use inheritance to override this
setting (which is the recommended way to do it).

–config [configfile]
Run wvdial with configfile as the configuration file (instead of
/etc/wvdial.conf). This is mainly useful only if you want to
have per-user configurations, or you want to avoid having dial-
up information (usernames, passwords, calling card numbers,
etc.) in a system wide configuration file.

Don’t output debug information to the syslog daemon (only useful
together with –chat).

–help Prints a short message describing how to use wvdial and exits.

Displays wvdial’s version number and exits.

wvdial is normally run without command line options, in which case it
reads its configuration from the [Dialer Defaults] section of
/etc/wvdial.conf. (The configuration file is described in more detail
in wvdial.conf(5) manual page.)

One or more sections of /etc/wvdial.conf may be specified on the com-
mand line. Settings in these sections will override settings in
[Dialer Defaults].

For example, the command:
wvdial phone2

will read default options from the [Dialer Defaults] section, then
override any or all of the options with those found in the [Dialer
phone2] section.

If more than one section is specified, they are processed in the order
they are given. Each section will override all the sections that came
before it.

For example, the command:
wvdial phone2 pulse shh

will read default options from the [Dialer Defaults] section, then
override any or all of the options with those found in the [Dialer
phone2] section, followed by the [Dialer pulse] section, and lastly the
[Dialer shh] section.

Using this method, it is possible to easily configure wvdial to switch
between different internet providers, modem init strings, account
names, and so on without specifying the same configuration information
over and over.


“Intelligent” programs are frustrating when they don’t work right.
This version of wvdial has only minimal support for disabling or over-
riding its “intelligence”, with the “Stupid Mode”, “Login Prompt”, and
“Password Prompt” options. So, in general if you have a nice ISP, it
will probably work, and if you have a weird ISP, it might not.

Still, it’s not much good if it doesn’t work for you, right? Don’t be
fooled by the fact that wvdial finally made it to version 1.00; it
could well contain many bugs and misfeatures. Let us know if you have
problems by sending e-mail to .

Also, there is now a mailing list for discussion about wvdial. If you
are having problems, or have anything else to say, send e-mail to

You may encounter some error messages if you don’t have write access to
/etc/ppp/pap-secrets and /etc/ppp/chap-secrets. Unfortunately, there’s
really no nice way around this yet.


Configuration file which contains modem, dialing, and login
information. See

Serial port devices.

Required for correct authentication in pppd version 2.3.0 or

Contains a list of usernames and passwords used by pppd for
authentication. wvdial maintains this list automatically.


Dave Coombs and Avery Pennarun for Net Integration Technologies, as
part of the Worldvisions Weaver project. We would like to thank SuSE
and RedHat for adding a number of various cool features to Thanks guys!


wvdial.conf(5), wvdialconf(1), pppd(8), chat(8).


Worldvisions WvDial May 2001 WVDIAL(1)

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mkdirhier – makes a directory hierarchy

mkdirhier directory …

The mkdirhier command creates the specified directories. Unlike mkdir
if any of the parent directories of the specified directory do not
exist, it creates them as well.


X Version 11 imake 1.0.2 MKDIRHIER(1)

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modinfo – program to show information about a Linux Kernel module

modinfo [ -0 ] [ -F field ] [ -k kernel ] [ modulename|filename … ]

modinfo -V

modinfo -h

modinfo extracts information from the Linux Kernel modules given on the
command line. If the module name is not a filename, then the /lib/mod-
ules/version directory is searched, as done by modprobe(8).

modinfo by default lists each attribute of the module in form fieldname
: value, for easy reading. The filename is listed the same way
(although it’s not really an attribute).

This version of modinfo can understand modules of any Linux Kernel

-V –version
Print the modinfo version. Note BACKWARDS COMPATIBILITY below:
you might be printing the version of modinfo.old.

-F –field
Only print this field value, one per line. This is most useful
for scripts. Field names are case-insenitive. Common fields
(which may not be in every module) include author, description,
license, param, depends, and alias. There are often multiple
param, alias and depends fields. The special field filename
lists the filename of the module.

-k kernel
Provide information about a kernel other than the running one.
This is particularly useful for distributions needing to extract
information from a newly installed (but not yet running) set of
kernel modules. For example, you wish to find which firmware
files are needed by various modules in a new kernel for which
you must make an initrd image prior to booting.

-0 –null
Use the ASCII zero character to separate field values, instead
of a new line. This is useful for scripts, since a new line can
theoretically appear inside a field.

-a -d -l -p -n
These are shortcuts for author, description, license. param and
filename respectively, to ease the transition from the old modu-
tils modinfo.

This version of modinfo is for kernel modules 2.5.48 and above. If it
detects a kernel with support for old-style modules, it will attempt to
run modprobe.old in its place, so it is completely transparent to the

Note that the output of this version of modinfo is simpler and more
regular than the older version: scripts attempting to use the default
output may get confused with complex fields.

You can force the new modinfo to always be used, by setting the
NEW_MODINFO environment variable.

This manual page Copyright 2003, Rusty Russell, IBM Corporation.

modprobe(8), modinfo.old(8)

22 August 2008 MODINFO(8)

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mkfs – build a Linux file system

mkfs [ -V ] [ -t fstype ] [ fs-options ] filesys [ blocks ]

mkfs is used to build a Linux file system on a device, usually a hard
disk partition. filesys is either the device name (e.g. /dev/hda1,
/dev/sdb2). blocks is the number of blocks to be used for the file

The exit code returned by mkfs is 0 on success and 1 on failure.

In actuality, mkfs is simply a front-end for the various file system
builders (mkfs.fstype) available under Linux. The file system-specific
builder is searched for in a number of directories like perhaps /sbin,
/sbin/fs, /sbin/fs.d, /etc/fs, /etc (the precise list is defined at
compile time but at least contains /sbin and /sbin/fs), and finally in
the directories listed in the PATH environment variable. Please see
the file system-specific builder manual pages for further details.

-V Produce verbose output, including all file system-specific com-
mands that are executed. Specifying this option more than once
inhibits execution of any file system-specific commands. This
is really only useful for testing.

-t fstype
Specifies the type of file system to be built. If not speci-
fied, the default file system type (currently ext2) is used.

File system-specific options to be passed to the real file sys-
tem builder. Although not guaranteed, the following options are
supported by most file system builders.

-c Check the device for bad blocks before building the file system.

-l filename
Read the bad blocks list from filename

-v Produce verbose output.

All generic options must precede and not be combined with file system-
specific options. Some file system-specific programs do not support
the -v (verbose) option, nor return meaningful exit codes. Also, some
file system-specific programs do not automatically detect the device
size and require the blocks parameter to be specified.

David Engel (
Fred N. van Kempen (
Ron Sommeling (
The manual page was shamelessly adapted from Remy Card’s version for
the ext2 file system.

fs(5), badblocks(8), fsck(8), mkdosfs(8), mke2fs(8), mkfs.bfs(8),
mkfs.ext2(8), mkfs.ext3(8), mkfs.minix(8), mkfs.msdos(8), mkfs.vfat(8),
mkfs.xfs(8), mkfs.xiafs(8)

The mkfs command is part of the util-linux-ng package and is available

Version 1.9 Jun 1995 MKFS(8)

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