31 lines
1.2 KiB
Markdown
31 lines
1.2 KiB
Markdown
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Title: Numeric arguments in emacs
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I'm starting an 'emacs trick of the day' sequence with:
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- Function name: *universal-argument*
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- Typical Key binding: `C-u`
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- How to get help: `C-h f universal-argument`
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- Usage: `C-u`
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Receive a numeric argument that is given to the next called function,
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when no numeric argument is typed, the value defaults to `4`. So today
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you can try:
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- `C-u 9 C-n`, that move cursor vertically down 9 lines
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- `C-u C-k` which kills 4 lines
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- `C-u C-u C-k` which kills 4 × 4, 16 lines
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- `C-u 10 n` which enters `nnnnnnnnnn`
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You may ask, what about if I want to input 25 '6' ? `C-u 256` can't work
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... so you just have to separate with another `C-u`: `C-u 25 C-u 1` gives
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`6666666666666666666666666`.
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Some functions does not have the simple 'repeating' effect of
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receiving a numeric parameter, for example, running `C-u C-l` does not
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recenter 4 times your screen! but the help page of
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*recenter-top-bottom* states that:
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> A prefix argument is handled like 'recenter':
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> With numeric prefix ARG, move current line to window-line ARG.
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> With plain `C-u`, move current line to window center. A negative argument to C-l move the current line to the line ARG from the bottom of the screen.
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