51 lines
1.3 KiB
Text
51 lines
1.3 KiB
Text
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# Contributed by Noah Friedman.
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# To avoid using a function in bash, you can use the `builtin' or
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# `command' builtins, but neither guarantees that you use an external
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# program instead of a bash builtin if there's a builtin by that name. So
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# this function can be used like `command' except that it guarantees the
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# program is external by first disabling any builtin by that name. After
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# the command is done executing, the state of the builtin is restored.
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function external ()
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{
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local state=""
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local exit_status
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if builtin_p "$1"; then
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state="builtin"
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enable -n "$1"
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fi
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command "$@"
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exit_status=$?
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if [ "$state" = "builtin" ]; then
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enable "$1"
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fi
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return ${exit_status}
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}
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# What is does is tell you if a particular keyword is currently enabled as
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# a shell builtin. It does NOT tell you if invoking that keyword will
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# necessarily run the builtin. For that, do something like
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#
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# test "$(builtin type -type [keyword])" = "builtin"
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#
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# Note also, that disabling a builtin with "enable -n" will make builtin_p
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# return false, since the builtin is no longer available.
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function builtin_p ()
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{
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local word
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set $(builtin type -all -type "$1")
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for word in "$@" ; do
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if [ "${word}" = "builtin" ]; then
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return 0
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fi
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done
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return 1
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}
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