[821] | 1 | #
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| 2 | # For a description of the syntax of this configuration file,
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| 3 | # see scripts/kbuild/config-language.txt.
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| 4 | #
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| 5 |
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| 6 | menu "Shells"
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| 7 |
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| 8 | choice
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| 9 | prompt "Choose your default shell"
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[1770] | 10 | default FEATURE_SH_IS_NONE
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[821] | 11 | help
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| 12 | Choose a shell. The ash shell is the most bash compatible
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| 13 | and full featured one.
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| 14 |
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[1770] | 15 | config FEATURE_SH_IS_ASH
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| 16 | select ASH
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[821] | 17 | bool "ash"
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| 18 |
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[1770] | 19 | config FEATURE_SH_IS_HUSH
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| 20 | select HUSH
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[821] | 21 | bool "hush"
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| 22 |
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[1770] | 23 | config FEATURE_SH_IS_LASH
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| 24 | select LASH
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[821] | 25 | bool "lash"
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| 26 |
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[1770] | 27 | config FEATURE_SH_IS_MSH
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| 28 | select MSH
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[821] | 29 | bool "msh"
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| 30 |
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[1770] | 31 | config FEATURE_SH_IS_NONE
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[821] | 32 | bool "none"
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| 33 |
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| 34 | endchoice
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| 35 |
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[1770] | 36 | config ASH
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[821] | 37 | bool "ash"
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| 38 | default n
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[1770] | 39 | select TEST
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[821] | 40 | help
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| 41 | Tha 'ash' shell adds about 60k in the default configuration and is
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| 42 | the most complete and most pedantically correct shell included with
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| 43 | busybox. This shell is actually a derivative of the Debian 'dash'
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| 44 | shell (by Herbert Xu), which was created by porting the 'ash' shell
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| 45 | (written by Kenneth Almquist) from NetBSD.
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| 46 |
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| 47 | comment "Ash Shell Options"
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[1770] | 48 | depends on ASH
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[821] | 49 |
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[1770] | 50 | config ASH_JOB_CONTROL
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[821] | 51 | bool "Job control"
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| 52 | default y
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[1770] | 53 | depends on ASH
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[821] | 54 | help
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| 55 | Enable job control in the ash shell.
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| 56 |
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[1770] | 57 | config ASH_READ_NCHARS
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[821] | 58 | bool "'read -n N' and 'read -s' support"
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| 59 | default n
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[1770] | 60 | depends on ASH
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[821] | 61 | help
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| 62 | 'read -n N' will return a value after N characters have been read.
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| 63 | 'read -s' will read without echoing the user's input.
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| 64 |
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[1770] | 65 | config ASH_READ_TIMEOUT
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[821] | 66 | bool "'read -t S' support."
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| 67 | default n
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[1770] | 68 | depends on ASH
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[821] | 69 | help
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| 70 | 'read -t S' will return a value after S seconds have passed.
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| 71 | This implementation will allow fractional seconds, expressed
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| 72 | as a decimal fraction, e.g. 'read -t 2.5 foo'.
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| 73 |
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[1770] | 74 | config ASH_ALIAS
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[821] | 75 | bool "alias support"
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| 76 | default y
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[1770] | 77 | depends on ASH
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[821] | 78 | help
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| 79 | Enable alias support in the ash shell.
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| 80 |
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[1770] | 81 | config ASH_MATH_SUPPORT
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[821] | 82 | bool "Posix math support"
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| 83 | default y
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[1770] | 84 | depends on ASH
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[821] | 85 | help
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| 86 | Enable math support in the ash shell.
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| 87 |
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[1770] | 88 | config ASH_MATH_SUPPORT_64
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[821] | 89 | bool "Extend Posix math support to 64 bit"
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| 90 | default n
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[1770] | 91 | depends on ASH_MATH_SUPPORT
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[821] | 92 | help
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| 93 | Enable 64-bit math support in the ash shell. This will make
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| 94 | the shell slightly larger, but will allow computation with very
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| 95 | large numbers.
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| 96 |
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[1770] | 97 | config ASH_GETOPTS
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[821] | 98 | bool "Builtin getopt to parse positional parameters"
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| 99 | default n
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[1770] | 100 | depends on ASH
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[821] | 101 | help
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| 102 | Enable getopts builtin in the ash shell.
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| 103 |
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[1770] | 104 | config ASH_BUILTIN_ECHO
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[821] | 105 | bool "Builtin version of 'echo'"
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| 106 | default y
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[1770] | 107 | select ECHO
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| 108 | depends on ASH
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[821] | 109 | help
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[1770] | 110 | Enable support for echo, builtin to ash.
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[821] | 111 |
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[1770] | 112 | config ASH_BUILTIN_TEST
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[821] | 113 | bool "Builtin version of 'test'"
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| 114 | default y
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[1770] | 115 | select TEST
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| 116 | depends on ASH
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[821] | 117 | help
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[1770] | 118 | Enable support for test, builtin to ash.
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[821] | 119 |
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[1770] | 120 | config ASH_CMDCMD
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[821] | 121 | bool "'command' command to override shell builtins"
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| 122 | default n
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[1770] | 123 | depends on ASH
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[821] | 124 | help
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| 125 | Enable support for the ash 'command' builtin, which allows
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| 126 | you to run the specified command with the specified arguments,
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| 127 | even when there is an ash builtin command with the same name.
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| 128 |
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[1770] | 129 | config ASH_MAIL
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[821] | 130 | bool "Check for new mail on interactive shells"
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| 131 | default y
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[1770] | 132 | depends on ASH
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[821] | 133 | help
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| 134 | Enable "check for new mail" in the ash shell.
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| 135 |
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[1770] | 136 | config ASH_OPTIMIZE_FOR_SIZE
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[821] | 137 | bool "Optimize for size instead of speed"
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| 138 | default y
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[1770] | 139 | depends on ASH
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[821] | 140 | help
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| 141 | Compile ash for reduced size at the price of speed.
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| 142 |
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[1770] | 143 | config ASH_RANDOM_SUPPORT
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[821] | 144 | bool "Pseudorandom generator and variable $RANDOM"
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| 145 | default n
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[1770] | 146 | depends on ASH
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[821] | 147 | help
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| 148 | Enable pseudorandom generator and dynamic variable "$RANDOM".
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| 149 | Each read of "$RANDOM" will generate a new pseudorandom value.
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| 150 | You can reset the generator by using a specified start value.
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| 151 | After "unset RANDOM" then generator will switch off and this
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| 152 | variable will no longer have special treatment.
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| 153 |
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[1770] | 154 | config ASH_EXPAND_PRMT
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[821] | 155 | bool "Expand prompt string"
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| 156 | default n
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[1770] | 157 | depends on ASH
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[821] | 158 | help
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| 159 | "PS#" may be contain volatile content, such as backquote commands.
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| 160 | This option recreates the prompt string from the environment
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| 161 | variable each time it is displayed.
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| 162 |
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[1770] | 163 | config HUSH
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[821] | 164 | bool "hush"
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| 165 | default n
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[1770] | 166 | select TRUE
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| 167 | select FALSE
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| 168 | select TEST
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[821] | 169 | help
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| 170 | hush is a very small shell (just 18k) and it has fairly complete
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| 171 | Bourne shell grammar. It even handles all the normal flow control
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| 172 | options such as if/then/elif/else/fi, for/in/do/done, while loops,
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| 173 | etc.
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| 174 |
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| 175 | It does not handle case/esac, select, function, here documents ( <<
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| 176 | word ), arithmetic expansion, aliases, brace expansion, tilde
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| 177 | expansion, &> and >& redirection of stdout+stderr, etc.
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| 178 |
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[1770] | 179 | config HUSH_HELP
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| 180 | bool "help builtin"
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| 181 | default n
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| 182 | depends on HUSH
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| 183 | help
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| 184 | Enable help builtin in hush. Code size + ~1 kbyte.
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[821] | 185 |
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[1770] | 186 | config HUSH_INTERACTIVE
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| 187 | bool "Interactive mode"
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| 188 | default y
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| 189 | depends on HUSH
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| 190 | help
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| 191 | Enable interactive mode (prompt and command editing).
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| 192 | Without this, hush simply reads and executes commands
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| 193 | from stdin just like a shell script from the file.
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| 194 | No prompt, no PS1/PS2 magic shell variables.
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| 195 |
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| 196 | config HUSH_JOB
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| 197 | bool "Job control"
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| 198 | default n
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| 199 | depends on HUSH_INTERACTIVE
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| 200 | help
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| 201 | Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
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| 202 | command (not entire shell), fg/bg builtins work. Without this option,
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| 203 | "cmd &" still works by simply spawning a process and immediately
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| 204 | prompting for next command (or executing next command in a script),
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| 205 | but no separate process group is formed.
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| 206 |
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| 207 | config HUSH_TICK
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| 208 | bool "Process substitution"
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| 209 | default n
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| 210 | depends on HUSH
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| 211 | help
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| 212 | Enable process substitution `command` and $(command) in hush.
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| 213 |
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| 214 | config HUSH_IF
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| 215 | bool "Support if/then/elif/else/fi"
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| 216 | default n
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| 217 | depends on HUSH
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| 218 | help
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| 219 | Enable if/then/elif/else/fi in hush.
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| 220 |
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| 221 | config HUSH_LOOPS
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| 222 | bool "Support for, while and until loops"
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| 223 | default n
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| 224 | depends on HUSH
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| 225 | help
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| 226 | Enable for, while and until loops in hush.
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| 227 |
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| 228 | config LASH
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[821] | 229 | bool "lash"
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| 230 | default n
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[1770] | 231 | select TRUE
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| 232 | select FALSE
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| 233 | select TEST
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[821] | 234 | help
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| 235 | lash is the very smallest shell (adds just 10k) and it is quite
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| 236 | usable as a command prompt, but it is not suitable for any but the
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| 237 | most trivial scripting (such as an initrd that calls insmod a few
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| 238 | times) since it does not understand any Bourne shell grammar. It
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| 239 | does handle pipes, redirects, and job control though. Adding in
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| 240 | command editing makes it a very nice lightweight command prompt.
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| 241 |
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| 242 |
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[1770] | 243 | config MSH
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[821] | 244 | bool "msh"
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| 245 | default n
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[1770] | 246 | select TRUE
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| 247 | select FALSE
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| 248 | select TEST
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[821] | 249 | help
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| 250 | The minix shell (adds just 30k) is quite complete and handles things
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| 251 | like for/do/done, case/esac and all the things you expect a Bourne
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| 252 | shell to do. It is not always pedantically correct about Bourne
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| 253 | shell grammar (try running the shell testscript "tests/sh.testcases"
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| 254 | on it and compare vs bash) but for most things it works quite well.
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| 255 | It also uses only vfork, so it can be used on uClinux systems.
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| 256 |
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| 257 | comment "Bourne Shell Options"
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[1770] | 258 | depends on MSH || LASH || HUSH || ASH
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[821] | 259 |
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[1770] | 260 | config FEATURE_SH_EXTRA_QUIET
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[821] | 261 | bool "Hide message on interactive shell startup"
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| 262 | default n
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[1770] | 263 | depends on MSH || LASH || HUSH || ASH
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[821] | 264 | help
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| 265 | Remove the busybox introduction when starting a shell.
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| 266 |
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[1770] | 267 | config FEATURE_SH_STANDALONE
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[821] | 268 | bool "Standalone shell"
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| 269 | default n
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[1770] | 270 | depends on (MSH || LASH || HUSH || ASH) && FEATURE_PREFER_APPLETS
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[821] | 271 | help
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[1770] | 272 | This option causes busybox shells to use busybox applets
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[821] | 273 | in preference to executables in the PATH whenever possible. For
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| 274 | example, entering the command 'ifconfig' into the shell would cause
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| 275 | busybox to use the ifconfig busybox applet. Specifying the fully
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| 276 | qualified executable name, such as '/sbin/ifconfig' will still
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| 277 | execute the /sbin/ifconfig executable on the filesystem. This option
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| 278 | is generally used when creating a statically linked version of busybox
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| 279 | for use as a rescue shell, in the event that you screw up your system.
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| 280 |
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[1770] | 281 | This is implemented by re-execing /proc/self/exe (typically)
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| 282 | with right parameters. Some selected applets ("NOFORK" applets)
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| 283 | can even be executed without creating new process.
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| 284 | Instead, busybox will call <applet>_main() internally.
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[821] | 285 |
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[1770] | 286 | However, this causes problems in chroot jails without mounted /proc
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| 287 | and with ps/top (command name can be shown as 'exe' for applets
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| 288 | started this way).
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| 289 | # untrue?
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| 290 | # Note that this will *also* cause applets to take precedence
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| 291 | # over shell builtins of the same name. So turning this on will
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| 292 | # eliminate any performance gained by turning on the builtin "echo"
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| 293 | # and "test" commands in ash.
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| 294 | # untrue?
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| 295 | # Note that when using this option, the shell will attempt to directly
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| 296 | # run '/bin/busybox'. If you do not have the busybox binary sitting in
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| 297 | # that exact location with that exact name, this option will not work at
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| 298 | # all.
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[821] | 299 |
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[1770] | 300 | config CTTYHACK
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| 301 | bool "cttyhack"
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[821] | 302 | default n
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| 303 | help
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[1770] | 304 | One common problem reported on the mailing list is "can't access tty;
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| 305 | job control turned off" error message which typically appears when
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| 306 | one tries to use shell with stdin/stdout opened to /dev/console.
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| 307 | This device is special - it cannot be a controlling tty.
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[821] | 308 |
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[1770] | 309 | Proper solution is to use correct device instead of /dev/console.
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[821] | 310 |
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[1770] | 311 | cttyhack provides "quick and dirty" solution to this problem.
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| 312 | It analyzes stdin with various ioctls, trying to determine whether
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| 313 | it is a /dev/ttyN or /dev/ttySN (virtual terminal or serial line).
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| 314 | If it detects one, it closes stdin/out/err and reopens that device.
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| 315 | Then it executes given program. Usage example for /etc/inittab
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| 316 | (for busybox init):
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[821] | 317 |
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[1770] | 318 | ::respawn:/bin/cttyhack /bin/sh
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[821] | 319 |
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| 320 | endmenu
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