busybox.sgml

手机嵌入式Linux下可用的busybox源码

	<sect1 id="swapoff">
	    <title>swapoff</title>

		<para>
		Usage: swapoff [OPTION] [DEVICE]
		</para>

		<para>
		Stop swapping virtual memory pages on DEVICE.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-a	Stop swapping on all swap devices
		</screen>
		</para>
	</sect1>

	<sect1 id="swapon">
	    <title>swapon</title>

		<para>
		Usage: swapon [OPTION] [DEVICE]
		</para>

		<para>
		Start swapping virtual memory pages on the given device.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-a	Start swapping on all swap devices
		</screen>
		</para>
	</sect1>

	<sect1 id="sync">
	    <title>sync</title>

		<para>
		Usage: sync
		</para>

		<para>
		Write all buffered filesystem blocks to disk.
		</para>
	</sect1>

	<sect1 id="syslogd">
	    <title>syslogd</title>

		<para>
		Usage: syslogd [OPTION]...
		</para>

		<para>
		Linux system and kernel (provides klogd) logging
		utility. Note that this version of syslogd/klogd ignores
		/etc/syslog.conf.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-m NUM	Interval between MARK lines (default=20min, 0=off)
			-n	Run as a foreground process
			-K	Do not start up the klogd process
			-O FILE	Use an alternate log file (default=/var/log/messages)
			-R HOST[:PORT] Log remotely to IP or hostname on PORT (default PORT=514/UDP)
			-L      Log locally as well as network logging (default is network only)
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
		$ syslogd -R masterlog:514
		$ syslogd -R 192.168.1.1:601
		</screen>
		</para>
	</sect1>

	<sect1 id="tail">
	    <title>tail</title>

		<para>
		Usage: tail [OPTION] [FILE]...
		</para>

		<para>
		Print last 10 lines of each FILE to standard output.
		With more than one FILE, precede each with a header
		giving the file name. With no FILE, or when FILE is -,
		read stdin.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-n NUM	Print last NUM lines instead of last 10
			-f	Output data as the file grows.  This version
				of 'tail -f' supports only one file at a time.
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ tail -n 1 /etc/resolv.conf
			nameserver 10.0.0.1
		</screen>
		</para>
	</sect1>

	<sect1 id="tar">
	    <title>tar</title>

		<para>
		Usage: tar [MODE] [OPTION] [FILE]...
		</para>

		<para>
		
		</para>

		<para>
		MODE may be chosen from
		</para>

		<para>
		<screen>
			c	Create
			x	Extract
			t	List
		</screen>
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			f FILE			Use FILE for tarfile (or stdin if '-')
			O				Extract to stdout
			exclude FILE	File to exclude
			v				List files processed
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ zcat /tmp/tarball.tar.gz | tar -xf -
			$ tar -cf /tmp/tarball.tar /usr/local
		</screen>
		</para>
	</sect1>

	<sect1 id="tee">
	    <title>tee</title>

		<para>
		Usage: tee [OPTION]... [FILE]...
		</para>

		<para>
		Copy stdin to FILE(s), and also to stdout.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-a	Append to the given FILEs, do not overwrite
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ echo "Hello" | tee /tmp/foo
			Hello
			$ cat /tmp/foo
			Hello
		</screen>
		</para>
	</sect1>

	<sect1 id="telnet">
	    <title>telnet</title>

		<para>
		Usage: telnet HOST [PORT]
		</para>

		<para>
		Establish interactive communication with another
		computer over a network using the TELNET protocol.
		</para>
	</sect1>

	<sect1 id="test">
	    <title>test, [</title>

		<para>
		Usage: test EXPRESSION
		</para>

		<para>
		   or: [ EXPRESSION ]
		</para>

		<para>
		Check file types and compare values returning an exit
		code determined by the value of EXPRESSION.
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ test 1 -eq 2
			$ echo $?
			1
			$ test 1 -eq 1
			$ echo $?
			0
			$ [ -d /etc ]
			$ echo $?
			0
			$ [ -d /junk ]
			$ echo $?
			1
		</screen>
		</para>
	</sect1>

	<sect1 id="touch">
	    <title>touch</title>

		<para>
		Usage: touch [OPTION]... FILE...
		</para>

		<para>
		Update the last-modified date on (or create) FILE(s).
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-c	Do not create files
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ ls -l /tmp/foo
			/bin/ls: /tmp/foo: No such file or directory
			$ touch /tmp/foo
			$ ls -l /tmp/foo
			-rw-rw-r--    1 andersen andersen        0 Apr 15 01:11 /tmp/foo
		</screen>
		</para>
	</sect1>

	<sect1 id="tr">
	    <title>tr</title>

		<para>
		Usage: tr [OPTION]... STRING1 [STRING2]
		</para>

		<para>
		Translate, squeeze, and/or delete characters from stdin,
		writing to stdout.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-c	Take complement of STRING1
			-d	Delete input characters coded STRING1
			-s	Squeeze multiple output characters of STRING2 into one character
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ echo "gdkkn vnqkc" | tr [a-y] [b-z]
			hello world
		</screen>
		</para>
	</sect1>

	<sect1 id="true">
	    <title>true</title>

		<para>
		Usage: true
		</para>

		<para>
		Return an exit code of TRUE (1).
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ true
			$ echo $?
			0
		</screen>
		</para>
	</sect1>

	<sect1 id="tty">
	    <title>tty</title>

		<para>
		Usage: tty
		</para>

		<para>
		Print the file name of the terminal connected to stdin.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-s	Print nothing, only return an exit status
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ tty
			/dev/tty2
		</screen>
		</para>
	</sect1>

	<sect1 id="umount">
	    <title>umount</title>

		<para>
		Usage: umount [OPTION]... DEVICE|DIRECTORY
		</para>

		<para>
		
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-a	Unmount all file systems
			-r	Try to remount devices as read-only if mount is busy
			-f	Force filesystem umount (i.e., unreachable NFS server)
			-l	Do not free loop device (if a loop device has been used)
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ umount /dev/hdc1 
		</screen>
		</para>
	</sect1>

	<sect1 id="uname">
	    <title>uname</title>

		<para>
		Usage: uname [OPTION]...
		</para>

		<para>
		Print certain system information. With no OPTION, same
		as -s.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-a	Print all information
			-m	Print the machine (hardware) type
			-n	Print the machine's network node hostname
			-r	Print the operating system release
			-s	Print the operating system name
			-p	Print the host processor type
			-v	Print the operating system version
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ uname -a
			Linux debian 2.2.15pre13 #5 Tue Mar 14 16:03:50 MST 2000 i686 unknown
		</screen>
		</para>
	</sect1>

	<sect1 id="uniq">
	    <title>uniq</title>

		<para>
		Usage: uniq [INPUT [OUTPUT]]
		</para>

		<para>
		Discard all but one of successive identical lines from
		INPUT (or stdin), writing to OUTPUT (or stdout).
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
		-c		prefix lines by the number of occurrences
		-d		only print duplicate lines
		-u		only print unique lines
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ echo -e "a\na\nb\nc\nc\na" | sort | uniq
			a
			b
			c
		</screen>
		</para>
	</sect1>
	
	<sect1 id="unix2dos">
	    <title>unix2dos</title>

		<para>
		Usage: unix2dos < unixfile > dosfile
		</para>

		<para>
		Converts a text file from unix format to dos format.
		</para>

	</sect1>

	<sect1 id="unrpm">
	    <title>unrpm</title>

		<para>
		Usage: unrpm < package.rpm | gzip -d | cpio -idmuv
		</para>

		<para>
		Extracts an rpm archive.
		</para>

	</sect1>

	<sect1 id="update">
	    <title>update</title>

		<para>
		Usage: update [OPTION]...
		</para>

		<para>
		Periodically flush filesystem buffers.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-S	Force use of sync(2) instead of flushing
			-s SECS	Call sync this often (default 30)
			-f SECS	Flush some buffers this often (default 5)
		</screen>
		</para>
	</sect1>

	<sect1 id="uptime">
	    <title>uptime</title>

		<para>
		Usage: uptime
		</para>

		<para>
		Display how long the system has been running since boot.
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ uptime
			  1:55pm  up  2:30, load average: 0.09, 0.04, 0.00
		</screen>
		</para>
	</sect1>

	<sect1 id="usleep">
	    <title>usleep</title>

		<para>
		Usage: usleep N
		</para>

		<para>
		Pause for N microseconds.
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ usleep 1000000
			[pauses for 1 second]
		</screen>
		</para>
	</sect1>

	<sect1 id="uudecode">
	    <title>uudecode</title>

		<para>
		Usage: uudecode [OPTION] [FILE]
		</para>

		<para>
		Uudecode a uuencoded file.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-o FILE	Direct output to FILE
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ uudecode -o busybox busybox.uu
			$ ls -l busybox
			-rwxr-xr-x   1 ams      ams        245264 Jun  7 21:35 busybox
		</screen>
		</para>
	</sect1>

	<sect1 id="uuencode">
	    <title>uuencode</title>

		<para>
		Usage: uuencode [OPTION] [INFILE] OUTFILE
		</para>

		<para>
		Uuencode a file.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-m	Use base64 encoding as of RFC1521
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ uuencode busybox busybox
			begin 755 busybox
			M?T5,1@$!`0````````````(``P`!````L+@$"#0```!0N@,``````#0`(``&amp;
			.....
			$ uudecode busybox busybox &gt; busybox.uu
			$
		</screen>
		</para>
	</sect1>

	<sect1 id="watchdog">
	    <title>watchdog</title>

		<para>
		Usage: watchdog device
		</para>

		<para>
		Periodically writes to watchdog device B<device>.
		</para>
	</sect1>

	<sect1 id="wc">
	    <title>wc</title>

		<para>
		Usage: wc [OPTION]... [FILE]...
		</para>

		<para>
		Print line, word, and byte counts for each FILE, and a
		total line if more than one FILE is specified. With no
		FILE, read stdin.
		</para>

		<para>
		Options:
		</para>

		<para>
		<screen>
			-c	Print the byte counts
			-l	Print the newline counts
			-L	Print the length of the longest line
			-w	Print the word counts
		</screen>
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ wc /etc/passwd
			     31      46    1365 /etc/passwd
		</screen>
		</para>
	</sect1>

	<sect1 id="which">
	    <title>which</title>

		<para>
		Usage: which [COMMAND]...
		</para>

		<para>
		Locate COMMAND(s).
		</para>

		<para>
		Example:
		</para>

		<para>
		<screen>
			$ which login