[6a3a178] | 1 | # extsprintf: extended POSIX-style sprintf
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| 2 |
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| 3 | Stripped down version of s[n]printf(3c). We make a best effort to throw an
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| 4 | exception when given a format string we don't understand, rather than ignoring
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| 5 | it, so that we won't break existing programs if/when we go implement the rest
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| 6 | of this.
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| 7 |
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| 8 | This implementation currently supports specifying
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| 9 |
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| 10 | * field alignment ('-' flag),
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| 11 | * zero-pad ('0' flag)
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| 12 | * always show numeric sign ('+' flag),
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| 13 | * field width
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| 14 | * conversions for strings, decimal integers, and floats (numbers).
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| 15 | * argument size specifiers. These are all accepted but ignored, since
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| 16 | Javascript has no notion of the physical size of an argument.
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| 17 |
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| 18 | Everything else is currently unsupported, most notably: precision, unsigned
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| 19 | numbers, non-decimal numbers, and characters.
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| 20 |
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| 21 | Besides the usual POSIX conversions, this implementation supports:
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| 22 |
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| 23 | * `%j`: pretty-print a JSON object (using node's "inspect")
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| 24 | * `%r`: pretty-print an Error object
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| 25 |
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| 26 | # Example
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| 27 |
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| 28 | First, install it:
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| 29 |
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| 30 | # npm install extsprintf
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| 31 |
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| 32 | Now, use it:
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| 33 |
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| 34 | var mod_extsprintf = require('extsprintf');
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| 35 | console.log(mod_extsprintf.sprintf('hello %25s', 'world'));
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| 36 |
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| 37 | outputs:
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| 38 |
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| 39 | hello world
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| 40 |
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| 41 | # Also supported
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| 42 |
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| 43 | **printf**: same args as sprintf, but prints the result to stdout
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| 44 |
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| 45 | **fprintf**: same args as sprintf, preceded by a Node stream. Prints the result
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| 46 | to the given stream.
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