kernel: scheduling fix for ARM

[minix.git] / commands / fetch / fetch.1

.\" $NetBSD: fetch.1,v 1.4 2009/02/07 15:25:51 wiz Exp $
.\"-
.\" Copyright (c) 2000-2004 Dag-Erling Coïdan Smørgrav
.\" All rights reserved.
.\" Portions Copyright (c) 1999 Massachusetts Institute of Technology; used
.\" by permission.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer
.\"    in this position and unchanged.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd February 5, 2009
.Dt FETCH 1
.Os
.Sh NAME
.Nm fetch
.Nd retrieve a file by Uniform Resource Locator
.Sh SYNOPSIS
.Nm
.Op Fl 146AFMRUadilmnqrsv
.Op Fl B Ar bytes
.Op Fl N Ar file
.Op Fl o Ar file
.Op Fl S Ar bytes
.Op Fl T Ar seconds
.Op Fl w Ar seconds
.Op Ar URL ...
.Sh DESCRIPTION
The
.Nm
utility provides a command-line interface to the
.Xr fetch 3
library.
Its purpose is to retrieve the file(s) pointed to by the URL(s) on the
command line.
.Pp
The following options are available:
.Bl -tag -width Fl
.It Fl 1
Stop and return exit code 0 at the first successfully retrieved file.
.It Fl 4
Forces
.Nm
to use IPv4 addresses only.
.It Fl 6
Forces
.Nm
to use IPv6 addresses only.
.It Fl A
Do not automatically follow
.Dq temporary
(302) redirects.
Some broken Web sites will return a redirect instead of a not-found
error when the requested object does not exist.
.It Fl a
Automatically retry the transfer upon soft failures.
.It Fl B Ar bytes
Specify the read buffer size in bytes.
The default is 4096 bytes.
Attempts to set a buffer size lower than this will be silently
ignored.
The number of reads actually performed is reported at verbosity level
two or higher (see the
.Fl v
flag).
.It Fl d
Use a direct connection even if a proxy is configured.
.It Fl F
In combination with the
.Fl r
flag, forces a restart even if the local and remote files have
different modification times.
Implies
.Fl R .
.It Fl i
Only fetch if it the output file is older than the referenced URL.
This option is overriden by
.Fl o Ar - .
.It Fl l
If the target is a file-scheme URL, make a symbolic link to the target
rather than trying to copy it.
.It Fl M
.It Fl m
Mirror mode: if the file already exists locally and has the same size
and modification time as the remote file, it will not be fetched.
Note that the
.Fl m
and
.Fl r
flags are mutually exclusive.
.It Fl N Ar file
Use
.Ar file
instead of
.Pa ~/.netrc
to look up login names and passwords for FTP sites.
See
.Xr ftp 1
for a description of the file format.
This feature is experimental.
.It Fl n
Do not preserve the modification time of the transferred file.
.It Fl o Ar file
Set the output file name to
.Ar file .
By default, a
.Dq pathname
is extracted from the specified URI, and
its basename is used as the name of the output file.
A
.Ar file
argument of
.Sq Li \&-
indicates that results are to be directed to the standard output.
If the
.Ar file
argument is a directory, fetched file(s) will be placed within the
directory, with name(s) selected as in the default behaviour.
.It Fl q
Quiet mode.
.It Fl R
The output files are precious, and should not be deleted under any
circumstances, even if the transfer failed or was incomplete.
.It Fl r
Restart a previously interrupted transfer.
Note that the
.Fl m
and
.Fl r
flags are mutually exclusive.
.It Fl S Ar bytes
Require the file size reported by the server to match the specified
value.
If it does not, a message is printed and the file is not fetched.
If the server does not support reporting file sizes, this option is
ignored and the file is fetched unconditionally.
.It Fl s
Print the size in bytes of each requested file, without fetching it.
.It Fl T Ar seconds
Set timeout value to
.Ar seconds .
Overrides the environment variables
.Ev FTP_TIMEOUT
for FTP transfers or
.Ev HTTP_TIMEOUT
for HTTP transfers if set.
.It Fl U
When using passive FTP, allocate the port for the data connection from
the low (default) port range.
See
.Xr ip 4
for details on how to specify which port range this corresponds to.
.It Fl v
Increase verbosity level.
.It Fl w Ar seconds
When the
.Fl a
flag is specified, wait this many seconds between successive retries.
.El
.Pp
If
.Nm
receives a
.Dv SIGINFO
signal (see the
.Cm status
argument for
.Xr stty 1 ) ,
the current transfer rate statistics will be written to the
standard error output, in the same format as the standard completion
message.
.Sh EXIT STATUS
The
.Nm
command returns zero on success, or one on failure.
If multiple URLs are listed on the command line,
.Nm
will attempt to retrieve each one of them in turn, and will return
zero only if they were all successfully retrieved.
.Sh ENVIRONMENT
.Bl -tag -width HTTP_TIMEOUT
.It Ev FTP_TIMEOUT
Maximum time, in seconds, to wait before aborting an FTP connection.
.It Ev HTTP_TIMEOUT
Maximum time, in seconds, to wait before aborting an HTTP connection.
.El
.Pp
See
.Xr fetch 3
for a description of additional environment variables, including
.Ev FETCH_BIND_ADDRESS ,
.Ev FTP_LOGIN ,
.Ev FTP_PASSIVE_MODE ,
.Ev FTP_PASSWORD ,
.Ev FTP_PROXY ,
.Ev ftp_proxy ,
.Ev HTTP_AUTH ,
.Ev HTTP_PROXY ,
.Ev http_proxy ,
.Ev HTTP_PROXY_AUTH ,
.Ev HTTP_REFERER ,
.Ev HTTP_USER_AGENT ,
.Ev NETRC ,
.Ev NO_PROXY
and
.Ev no_proxy .
.Sh SEE ALSO
.Xr fetch 3
.Sh HISTORY
The
.Nm
command appeared in
.Fx 2.1.5 .
This implementation first appeared in
.Fx 4.1 .
.Sh AUTHORS
.An -nosplit
The original implementation of
.Nm
was done by
.An Jean-Marc Zucconi Aq jmz@FreeBSD.org .
It was extensively re-worked for
.Fx 2.2
by
.An Garrett Wollman Aq wollman@FreeBSD.org ,
and later completely rewritten to use the
.Xr fetch 3
library by
.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org .
.Sh NOTES
The
.Fl b
and
.Fl t
options are no longer supported and will generate warnings.
They were workarounds for bugs in other OSes which this implementation
does not trigger.
.Pp
One cannot both use the
.Fl h ,
.Fl c ,
and
.Fl f
options and specify URLs on the command line.