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Sanitize a string for use as a filename
/**
* Extracted from node-sanitize (https://github.com/parshap/node-sanitize-filename/blob/master/index.js)
*
* Replaces characters in strings that are illegal/unsafe for filenames.
* Unsafe characters are either removed or replaced by a substitute set
* in the optional `options` object.
*
* Illegal Characters on Various Operating Systems
* / ? < > \ : * | "
* https://kb.acronis.com/content/39790
*
* Unicode Control codes
* C0 0x00-0x1f & C1 (0x80-0x9f)
* http://en.wikipedia.org/wiki/C0_and_C1_control_codes
*
* Reserved filenames on Unix-based systems (".", "..")
* Reserved filenames in Windows ("CON", "PRN", "AUX", "NUL", "COM1",
* "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9",
* "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", and
* "LPT9") case-insesitively and with or without filename extensions.
*
* Capped at 255 characters in length.
* http://unix.stackexchange.com/questions/32795/what-is-the-maximum-allowed-filename-and-folder-size-with-ecryptfs
*
* @param {String} input Original filename
* @param {Object} options {replacement: String}
* @return {String} Sanitized filename
*/
var truncate = require("truncate-utf8-bytes");
var illegalRe = /[\/\?<>\\:\*\|":]/g;
var controlRe = /[\x00-\x1f\x80-\x9f]/g;
var reservedRe = /^\.+$/;
var windowsReservedRe = /^(con|prn|aux|nul|com[0-9]|lpt[0-9])(\..*)?$/i;
function sanitize(input, replacement) {
var sanitized = input
.replace(illegalRe, replacement)
.replace(controlRe, replacement)
.replace(reservedRe, replacement)
.replace(windowsReservedRe, replacement);
return truncate(sanitized, 255);
}
module.exports = function (input, options) {
var replacement = (options && options.replacement) || '';
var output = sanitize(input, replacement);
if (replacement === '') {
return output;
}
return sanitize(output, '');
};
@desduvauchelle
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desduvauchelle commented Jun 7, 2021

Also, it seems that truncate would cut the file name extension?

@akshatsethi2
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akshatsethi2 commented Jun 6, 2022

@Alynva using this sanitized.split("").splice(0, 255).join("") is not a good idea, as complex symbols like emojis are made up of more than one character, so if you split a string containing a emoji, it will return an array of 2 elements

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