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https://github.com/fish-shell/fish-shell
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98449fec51
The previous change to use `argparse` for parity with every other builtin and function introduced a regression. Invocations that start with a negative number can fail because the negative value looks like an invalid flag.
56 lines
2 KiB
Fish
56 lines
2 KiB
Fish
function math --description "Perform math calculations in bc"
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if not set -q argv[2]
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# Make sure an invocation like `math "-1 + 1"` doesn't treat the string as an option.
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set argv -- $argv
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end
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set -l options 'h/help' 's/scale=' '#-val'
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argparse -n math --stop-nonopt --min-args=1 $options -- $argv
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or return
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if set -q _flag_help
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__fish_print_help math
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return 0
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end
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set -l scale 0 # default is integer arithmetic
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if set -q _flag_scale
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set scale $_flag_scale
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if not string match -q -r '^\d+$' "$scale"
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printf (_ "%s: Expected an integer to follow --scale") math >&2
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return 2 # missing argument is an error
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end
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end
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if set -q _flag_val
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# The expression began with a negative number. Put it back in the expression.
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# The correct thing is for the person calling us to insert a `--` separator before the
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# expression to stop parsing flags. But we'll work around that missing token here.
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set argv -$_flag_val $argv
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end
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# Set BC_LINE_LENGTH to a ridiculously high number so it only uses one line for most results.
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# We can't use 0 since some systems (including macOS) use an ancient bc that doesn't support it.
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# We also can't count on this being recognized since some BSD systems don't recognize this env
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# var at all and limit the line length to 70.
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set -lx BC_LINE_LENGTH 500
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set -l out (echo "scale=$scale; $argv" | bc)
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if set -q out[2]
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set out (string join '' (string replace \\ '' $out))
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end
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switch "$out"
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case ''
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# No output indicates an error occurred.
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return 3
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case 0
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# For historical reasons a zero result translates to a failure status.
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echo 0
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return 1
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case '*'
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# For historical reasons a non-zero result translates to a success status.
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echo $out
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return 0
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end
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end
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