cpuminer.1

.TH CPUMINER 1 "May 2014" "cpuminer 2.4"
.SH NAME
cpuminer \- CPU miner for Bitcoin and Litecoin
.SH SYNOPSIS
.B cpuminer
[\fIOPTION\fR]...
.SH DESCRIPTION
.B cpuminer
is a multi-threaded CPU miner for Bitcoin, Litecoin and other cryptocurrencies.
It supports the getwork and getblocktemplate (BIP 22) methods,
as well as the Stratum mining protocol.
.PP
In its normal mode of operation, \fBcpuminer\fR connects to a mining server
(specified with the \fB\-o\fR option), receives work from it and starts hashing.
As soon as a solution is found, it is submitted to the same mining server,
which can accept or reject it.
When using getwork or getblocktemplate,
\fBcpuminer\fR can take advantage of long polling, if the server supports it;
in any case, fresh work is fetched as needed.
When using the Stratum protocol this is not possible,
and the server is responsible for sending fresh work at least every minute;
if it fails to do so,
\fBcpuminer\fR may drop the connection and try reconnecting again.
.PP
By default, \fBcpuminer\fR writes all its messages to standard error.
On systems that have a syslog, the \fB\-\-syslog\fR option can be used
to write to it instead.
.PP
On start, the nice value of all miner threads is set to 19.
On Linux, the scheduling policy is also changed to SCHED_IDLE,
or to SCHED_BATCH if that fails.
On multiprocessor systems, \fBcpuminer\fR
automatically sets the CPU affinity of miner threads
if the number of threads is a multiple of the number of processors.
.SH EXAMPLES
To connect to a Litecoin mining pool that provides a Stratum server
at example.com on port 3333, authenticating as worker "foo" with password "bar":
.PP
.nf
.RS
cpuminer \-o stratum+tcp://example.com:3333 \-O foo:bar
.RE
.fi
.PP
To mine to a local Bitcoin testnet instance running on port 18332,
authenticating with username "rpcuser" and password "rpcpass":
.PP
.nf
.RS
cpuminer \-a sha256d \-o http://localhost:18332 \-O rpcuser:rpcpass \\
	\-\-coinbase\-addr=mpXwg4jMtRhuSpVq4xS3HFHmCmWp9NyGKt
.RE
.fi
.PP
To connect to a Litecoin P2Pool node running on my.server on port 9327,
mining in the background and having output sent to the syslog facility,
omitting the per-thread hashmeter output:
.PP
.nf
.RS
cpuminer \-BSq \-o http://my.server:9327
.RE
.fi
.SH OPTIONS
.TP
\fB\-a\fR, \fB\-\-algo\fR=\fIALGORITHM\fR
Set the hashing algorithm to use.
Default is scrypt.
Possible values are:
.RS 11
.TP 10
.B scrypt
scrypt(1024, 1, 1) (used by Litecoin)
.TP
.B scrypt:\fIN\fR
scrypt(\fIN\fR, 1, 1) (\fIN\fR must be a power of 2 greater than 1)
.TP
.B sha256d
SHA-256d (used by Bitcoin)
.RE
.TP
\fB\-\-benchmark\fR
Run in offline benchmark mode.
.TP
\fB\-B\fR, \fB\-\-background\fR
Run in the background as a daemon.
.TP
\fB\-\-cert\fR=\fIFILE\fR
Set an SSL certificate to use with the mining server.
Only supported when using the HTTPS protocol.
.TP
\fB\-\-coinbase\-addr\fR=\fIADDRESS\fR
Set a payout address for solo mining.
This is only used in getblocktemplate mode,
and only if the server does not provide a coinbase transaction.
.TP
\fB\-\-coinbase\-sig\fR=\fITEXT\fR
Set a string to be included in the coinbase (if allowed by the server).
This is only used in getblocktemplate mode.
.TP
\fB\-c\fR, \fB\-\-config\fR=\fIFILE\fR
Load options from a configuration file.
\fIFILE\fR must contain a JSON object
mapping long options to their arguments (as strings),
or to \fBtrue\fR if no argument is required.
Sample configuration file:

.nf
	{
		"url": "stratum+tcp://example.com:3333",
		"userpass": "foo:bar",
		"retry-pause": "10",
		"quiet": true
	}
.fi
.TP
\fB\-D\fR, \fB\-\-debug\fR
Enable debug output.
.TP
\fB\-h\fR, \fB\-\-help\fR
Print a help message and exit.
.TP
\fB\-\-no\-gbt\fR
Do not use the getblocktemplate RPC method.
.TP
\fB\-\-no\-getwork\fR
Do not use the getwork RPC method.
.TP
\fB\-\-no\-longpoll\fR
Do not use long polling.
.TP
\fB\-\-no\-redirect\fR
Ignore requests from the server to switch to a different URL.
.TP
\fB\-\-no\-stratum\fR
Do not switch to Stratum, even if the server advertises support for it.
.TP
\fB\-o\fR, \fB\-\-url\fR=[\fISCHEME\fR://][\fIUSERNAME\fR[:\fIPASSWORD\fR]@]\fIHOST\fR:\fIPORT\fR[/\fIPATH\fR]
Set the URL of the mining server to connect to.
Supported schemes are \fBhttp\fR, \fBhttps\fR and \fBstratum+tcp\fR.
If no scheme is specified, http is assumed.
Specifying a \fIPATH\fR is only supported for HTTP and HTTPS.
Specifying credentials has the same effect as using the \fB\-O\fR option.

By default, on HTTP and HTTPS,
the miner tries to use the getblocktemplate RPC method,
and falls back to using getwork if getblocktemplate is unavailable.
This behavior can be modified by using the \fB\-\-no\-gbt\fR
and \fB\-\-no\-getwork\fR options.
.TP
\fB\-O\fR, \fB\-\-userpass\fR=\fIUSERNAME\fR:\fIPASSWORD\fR
Set the credentials to use for connecting to the mining server.
Any value previously set with \fB\-u\fR or \fB\-p\fR is discarded.
.TP
\fB\-p\fR, \fB\-\-pass\fR=\fIPASSWORD\fR
Set the password to use for connecting to the mining server.
Any password previously set with \fB\-O\fR is discarded.
.TP
\fB\-P\fR, \fB\-\-protocol\-dump\fR
Enable output of all protocol-level activities.
.TP
\fB\-q\fR, \fB\-\-quiet\fR
Disable per-thread hashmeter output.
.TP
\fB\-r\fR, \fB\-\-retries\fR=\fIN\fR
Set the maximum number of times to retry if a network call fails.
If not specified, the miner will retry indefinitely.
.TP
\fB\-R\fR, \fB\-\-retry\-pause\fR=\fISECONDS\fR
Set how long to wait between retries. Default is 30 seconds.
.TP
\fB\-s\fR, \fB\-\-scantime\fR=\fISECONDS\fR
Set an upper bound on the time the miner can go without fetching fresh work.
This setting has no effect in Stratum mode or when long polling is activated.
Default is 5 seconds.
.TP
\fB\-S\fR, \fB\-\-syslog\fR
Log to the syslog facility instead of standard error.
.TP
\fB\-t\fR, \fB\-\-threads\fR=\fIN\fR
Set the number of miner threads.
If not specified, the miner will try to detect the number of available processors
and use that.
.TP
\fB\-T\fR, \fB\-\-timeout\fR=\fISECONDS\fR
Set a timeout for long polling.
.TP
\fB\-u\fR, \fB\-\-user\fR=\fIUSERNAME\fR
Set the username to use for connecting to the mining server.
Any username previously set with \fB\-O\fR is discarded.
.TP
\fB\-V\fR, \fB\-\-version\fR
Display version information and quit.
.TP
\fB\-x\fR, \fB\-\-proxy\fR=[\fISCHEME\fR://][\fIUSERNAME\fR:\fIPASSWORD\fR@]\fIHOST\fR:\fIPORT\fR
Connect to the mining server through a proxy.
Supported schemes are: \fBhttp\fR, \fBsocks4\fR, \fBsocks5\fR.
Since libcurl 7.18.0, the following are also supported:
\fBsocks4a\fR, \fBsocks5h\fR (SOCKS5 with remote name resolving).
If no scheme is specified, the proxy is treated as an HTTP proxy.
.SH ENVIRONMENT
The following environment variables can be specified in lower case or upper case;
the lower-case version has precedence. \fBhttp_proxy\fR is an exception
as it is only available in lower case.
.PP
.RS
.TP
\fBhttp_proxy\fR [\fISCHEME\fR://]\fIHOST\fR:\fIPORT\fR
Sets the proxy server to use for HTTP.
.TP
\fBHTTPS_PROXY\fR [\fISCHEME\fR://]\fIHOST\fR:\fIPORT\fR
Sets the proxy server to use for HTTPS.
.TP
\fBALL_PROXY\fR [\fISCHEME\fR://]\fIHOST\fR:\fIPORT\fR
Sets the proxy server to use if no protocol-specific proxy is set.
.RE
.PP
Using an environment variable to set the proxy has the same effect as
using the \fB\-x\fR option.
.SH AUTHOR
This variant is maintained by tpruvot@github.

Most of the code in the current version of cpuminer was written by
Pooler <pooler@litecoinpool.org> with contributions from others.
The original minerd was written by Jeff Garzik <jeff@garzik.org>.