freebsd-skq/usr.bin/fetch/fetch.1

.\"-
.\" Copyright (c) 2000-2014 Dag-Erling Smørgrav
.\" Copyright (c) 2013-2016 Michael Gmelin <freebsd@grem.de>
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.Dd October 29, 2020
.Dt FETCH 1
.Os
.Sh NAME
.Nm fetch
.Nd retrieve a file by Uniform Resource Locator
.Sh SYNOPSIS
.Nm
.Op Fl 146AadFlMmnPpqRrsUv
.Op Fl B Ar bytes
.Op Fl -bind-address= Ns Ar host
.Op Fl -ca-cert= Ns Ar file
.Op Fl -ca-path= Ns Ar dir
.Op Fl -cert= Ns Ar file
.Op Fl -crl= Ns Ar file
.Op Fl i Ar file
.Op Fl -key= Ns Ar file
.Op Fl N Ar file
.Op Fl -no-passive
.Op Fl -no-proxy= Ns Ar list
.Op Fl -no-sslv3
.Op Fl -no-tlsv1
.Op Fl -no-verify-hostname
.Op Fl -no-verify-peer
.Op Fl o Ar file
.Op Fl -referer= Ns Ar URL
.Op Fl S Ar bytes
.Op Fl T Ar seconds
.Op Fl -user-agent= Ns Ar agent-string
.Op Fl w Ar seconds
.Ar URL ...
.Nm
.Op Fl 146AadFlMmnPpqRrsUv
.Op Fl B Ar bytes
.Op Fl -bind-address= Ns Ar host
.Op Fl -ca-cert= Ns Ar file
.Op Fl -ca-path= Ns Ar dir
.Op Fl -cert= Ns Ar file
.Op Fl -crl= Ns Ar file
.Op Fl i Ar file
.Op Fl -key= Ns Ar file
.Op Fl N Ar file
.Op Fl -no-passive
.Op Fl -no-proxy= Ns Ar list
.Op Fl -no-sslv3
.Op Fl -no-tlsv1
.Op Fl -no-verify-hostname
.Op Fl -no-verify-peer
.Op Fl o Ar file
.Op Fl -referer= Ns Ar URL
.Op Fl S Ar bytes
.Op Fl T Ar seconds
.Op Fl -user-agent= Ns Ar agent-string
.Op Fl w Ar seconds
.Fl h Ar host Fl f Ar file Oo Fl c Ar dir Oc
.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 , -one-file
Stop and return exit code 0 at the first successfully retrieved file.
.It Fl 4 , -ipv4-only
Forces
.Nm
to use IPv4 addresses only.
.It Fl 6 , -ipv6-only
Forces
.Nm
to use IPv6 addresses only.
.It Fl A , -no-redirect
Do not automatically follow ``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 , -retry
Automatically retry the transfer upon soft failures.
.It Fl B Ar bytes , Fl -buffer-size= Ns Ar bytes
Specify the read buffer size in bytes.
The default is 16,384 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 -bind-address= Ns Ar host
Specifies a hostname or IP address to which sockets used for outgoing
connections will be bound.
.It Fl c Ar dir
The file to retrieve is in directory
.Ar dir
on the remote host.
This option is deprecated and is provided for backward compatibility
only.
.It Fl -ca-cert= Ns Ar file
[SSL]
Path to certificate bundle containing trusted CA certificates.
If not specified,
.Pa /usr/local/etc/ssl/cert.pem
is used.
If this file does not exist,
.Pa /etc/ssl/cert.pem
is used instead.
If neither file exists and no CA path has been configured,
OpenSSL's default CA cert and path settings apply.
The certificate bundle can contain multiple CA certificates.
The
.Pa security/ca_root_nss
port is a common source of a current CA bundle.
.It Fl -ca-path= Ns Ar dir
[SSL]
The directory
.Ar dir
contains trusted CA hashes.
.It Fl -cert= Ns Ar file
[SSL]
.Ar file
is a PEM encoded client certificate/key which will be used in
client certificate authentication.
.It Fl -crl= Ns Ar file
[SSL]
Points to certificate revocation list
.Ar file ,
which has to be in PEM format and may contain peer certificates that have
been revoked.
.It Fl d , -direct
Use a direct connection even if a proxy is configured.
.It Fl F , -force-restart
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 f Ar file
The file to retrieve is named
.Ar file
on the remote host.
This option is deprecated and is provided for backward compatibility
only.
.It Fl h Ar host
The file to retrieve is located on the host
.Ar host .
This option is deprecated and is provided for backward compatibility
only.
.It Fl i Ar file , Fl -if-modified-since= Ns Ar file
If-Modified-Since mode: the remote file will only be retrieved if it
is newer than
.Ar file
on the local host.
(HTTP only)
.It Fl -key= Ns Ar file
[SSL]
.Ar file
is a PEM encoded client key that will be used in client certificate
authentication in case key and client certificate are stored separately.
.It Fl l , -symlink
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
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 , Fl -netrc= Ns 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 , -no-mtime
Do not preserve the modification time of the transferred file.
.It Fl -no-passive
Forces the FTP code to use active mode.
.It Fl -no-proxy= Ns Ar list
Either a single asterisk, which disables the use of proxies
altogether, or a comma- or whitespace-separated list of hosts for
which proxies should not be used.
.It Fl -no-sslv3
[SSL]
Do not allow SSL version 3 when negotiating the connection.
This option is deprecated and is provided for backward compatibility
only.
SSLv3 is disabled by default.
Set
.Ev SSL_ALLOW_SSL3
to change this behavior.
.It Fl -no-tlsv1
[SSL]
Do not allow TLS version 1 when negotiating the connection.
.It Fl -no-verify-hostname
[SSL]
Do not verify that the hostname matches the subject of the
certificate presented by the server.
.It Fl -no-verify-peer
[SSL]
Do not verify the peer certificate against trusted CAs.
.It Fl o Ar file , Fl -output= Ns Ar file
Set the output file name to
.Ar file .
By default, a ``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 P
.It Fl p , -passive
Use passive FTP.
These flags have no effect, since passive FTP is the default, but are
provided for compatibility with earlier versions where active FTP was
the default.
To force active mode, use the
.Fl -no-passive
flag or set the
.Ev FTP_PASSIVE_MODE
environment variable to
.Ql NO .
.It Fl -referer= Ns Ar URL
Specifies the referrer URL to use for HTTP requests.
If
.Ar URL
is set to
.Dq auto ,
the document URL will be used as referrer URL.
.It Fl q , -quiet
Quiet mode.
.It Fl R , -keep-output
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
Restart a previously interrupted transfer.
Note that the
.Fl m
and
.Fl r
flags are mutually exclusive.
.It Fl S Ar bytes , Fl -require-size= Ns 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-size
Print the size in bytes of each requested file, without fetching it.
.It Fl T Ar seconds , Fl -timeout= Ns 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 , -passive-portrange-default
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 -user-agent= Ns Ar agent-string
Specifies the User-Agent string to use for HTTP requests.
This can be useful when working with HTTP origin or proxy servers that
differentiate between user agents.
.It Fl v , -verbose
Increase verbosity level.
.It Fl w Ar seconds , Fl -retry-delay= Ns 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 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_ACCEPT ,
.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 ,
.Ev no_proxy ,
.Ev SSL_CA_CERT_FILE ,
.Ev SSL_CA_CERT_PATH ,
.Ev SSL_CLIENT_CERT_FILE ,
.Ev SSL_CLIENT_KEY_FILE ,
.Ev SSL_CRL_FILE ,
.Ev SSL_ALLOW_SSL3 ,
.Ev SSL_NO_TLS1 ,
.Ev SSL_NO_TLS1_1 ,
.Ev SSL_NO_TLS1_2 ,
.Ev SSL_NO_VERIFY_HOSTNAME
and
.Ev SSL_NO_VERIFY_PEER .
.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.
.Pp
If the
.Fl i
argument is used and the remote file is not newer than the
specified file then the command will still return success,
although no file is transferred.
.Sh EXAMPLES
Silently try to fetch the URLs passed as parameters.
The first one will fail.
If the second URL succeeds the third one will not be tried:
.Bd -literal -offset indent
$ fetch -1 -q https://www.freebsd.org/bad.html \e
	ftp.freebsd.org/pub/FreeBSD/README.TXT \e
	https://www.fake.url
fetch: https://www.freebsd.org/bad.html: Not Found
.Ed
.Pp
Be verbose when retrieving the
.Pa README.TXT
file:
.Bd -literal -offset indent
$ fetch -v ftp.freebsd.org/pub/FreeBSD/README.TXT
resolving server address: ftp.freebsd.org:80
requesting http://ftp.freebsd.org/pub/FreeBSD/README.TXT
local size / mtime: 4259 / 1431015519
remote size / mtime: 4259 / 1431015519
README.TXT                                            4259  B   44 MBps    00s
.Ed
.Pp
Quietly save the
.Pa README.TXT
file as
.Pa myreadme.txt
and do not delete the output file under any circumstances:
.Bd -literal -offset indent
fetch -o myreadme.txt -q -R ftp.freebsd.org/pub/FreeBSD/README.TXT
.Ed
.Pp
Print the size of the requested file and identify the request with a custom user
agent string:
.Bd -literal -offset indent
$ fetch -s ftp.freebsd.org/pub/FreeBSD/README.TXT
--user-agent="Mozilla/5.0 (X11; FreeBSD x86_64; rv:78.0) Gecko/20100101"
3513231
.Ed
.Pp
Restart the transfer of the
.Pa README.TXT
file and retry the transfer upon soft failures:
.Bd -literal -offset indent
$ fetch -a -r http://ftp.freebsd.org/pub/FreeBSD/README.TXT
.Ed
.Sh SEE ALSO
.Xr fetch 3 ,
.Xr phttpget 8
.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 Mt jmz@FreeBSD.org .
It was extensively re-worked for
.Fx 2.2
by
.An Garrett Wollman Aq Mt wollman@FreeBSD.org ,
and later completely rewritten to use the
.Xr fetch 3
library by
.An Dag-Erling Sm\(/orgrav Aq Mt des@FreeBSD.org
and
.An Michael Gmelin Aq Mt freebsd@grem.de .
.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.