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| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | BusyBox - The Swiss Army Knife of Embedded Linux |
| 6 | |
| 7 | =head1 SYNTAX |
| 8 | |
| 9 | busybox <applet> [arguments...] # or |
| 10 | |
| 11 | <applet> [arguments...] # if symlinked |
| 12 | |
| 13 | =head1 DESCRIPTION |
| 14 | |
| 15 | BusyBox combines tiny versions of many common UNIX utilities into a single |
| 16 | small executable. It provides minimalist replacements for most of the utilities |
| 17 | you usually find in GNU coreutils, util-linux, etc. The utilities in BusyBox |
| 18 | generally have fewer options than their full-featured GNU cousins; however, the |
| 19 | options that are included provide the expected functionality and behave very |
| 20 | much like their GNU counterparts. |
| 21 | |
| 22 | BusyBox has been written with size-optimization and limited resources in mind. |
| 23 | It is also extremely modular so you can easily include or exclude commands (or |
| 24 | features) at compile time. This makes it easy to customize your embedded |
| 25 | systems. To create a working system, just add /dev, /etc, and a Linux kernel. |
| 26 | BusyBox provides a fairly complete POSIX environment for any small or embedded |
| 27 | system. |
| 28 | |
| 29 | BusyBox is extremely configurable. This allows you to include only the |
| 30 | components you need, thereby reducing binary size. Run 'make config' or 'make |
| 31 | menuconfig' to select the functionality that you wish to enable. Then run |
| 32 | 'make' to compile BusyBox using your configuration. |
| 33 | |
| 34 | After the compile has finished, you should use 'make install' to install |
| 35 | BusyBox. This will install the 'bin/busybox' binary, in the target directory |
| 36 | specified by CONFIG_PREFIX. CONFIG_PREFIX can be set when configuring BusyBox, |
| 37 | or you can specify an alternative location at install time (i.e., with a |
| 38 | command line like 'make CONFIG_PREFIX=/tmp/foo install'). If you enabled |
| 39 | any applet installation scheme (either as symlinks or hardlinks), these will |
| 40 | also be installed in the location pointed to by CONFIG_PREFIX. |
| 41 | |
| 42 | =head1 USAGE |
| 43 | |
| 44 | BusyBox is a multi-call binary. A multi-call binary is an executable program |
| 45 | that performs the same job as more than one utility program. That means there |
| 46 | is just a single BusyBox binary, but that single binary acts like a large |
| 47 | number of utilities. This allows BusyBox to be smaller since all the built-in |
| 48 | utility programs (we call them applets) can share code for many common |
| 49 | operations. |
| 50 | |
| 51 | You can also invoke BusyBox by issuing a command as an argument on the |
| 52 | command line. For example, entering |
| 53 | |
| 54 | /bin/busybox ls |
| 55 | |
| 56 | will also cause BusyBox to behave as 'ls'. |
| 57 | |
| 58 | Of course, adding '/bin/busybox' into every command would be painful. So most |
| 59 | people will invoke BusyBox using links to the BusyBox binary. |
| 60 | |
| 61 | For example, entering |
| 62 | |
| 63 | ln -s /bin/busybox ls |
| 64 | ./ls |
| 65 | |
| 66 | will cause BusyBox to behave as 'ls' (if the 'ls' command has been compiled |
| 67 | into BusyBox). Generally speaking, you should never need to make all these |
| 68 | links yourself, as the BusyBox build system will do this for you when you run |
| 69 | the 'make install' command. |
| 70 | |
| 71 | If you invoke BusyBox with no arguments, it will provide you with a list of the |
| 72 | applets that have been compiled into your BusyBox binary. |
| 73 | |
| 74 | =head1 COMMON OPTIONS |
| 75 | |
| 76 | Most BusyBox applets support the B<--help> argument to provide a terse runtime |
| 77 | description of their behavior. If the CONFIG_FEATURE_VERBOSE_USAGE option has |
| 78 | been enabled, more detailed usage information will also be available. |
| 79 | |
| 80 | =head1 COMMANDS |
| 81 | |
| 82 | Currently available applets include: |