A JavaScript equivalent of PHP’s addcslashes
function addcslashes (str, charlist) {
// http://kevin.vanzonneveld.net
// + original by: Brett Zamir (http://brett-zamir.me)
// % note 1: We show double backslashes in the return value example code below because a JavaScript string will not
// % note 1: render them as backslashes otherwise
// * example 1: addcslashes('foo[ ]', 'A..z'); // Escape all ASCII within capital A to lower z range, including square brackets
// * returns 1: "\\f\\o\\o\\[ \\]"
// * example 2: addcslashes("zoo['.']", 'z..A'); // Only escape z, period, and A here since not a lower-to-higher range
// * returns 2: "\\zoo['\\.']"
// * example 3: addcslashes("@a\u0000\u0010\u00A9", "\0..\37!@\177..\377") == '\\@a\\000\\020\\302\\251'); // Escape as octals those specified and less than 32 (0x20) or greater than 126 (0x7E), but not otherwise
// * returns 3: true
// * example 4: addcslashes("\u0020\u007E", "\40..\175") == '\\ ~'); // Those between 32 (0x20 or 040) and 126 (0x7E or 0176) decimal value will be backslashed if specified (not octalized)
// * returns 4: true
// * example 5: addcslashes("\r\u0007\n", '\0..\37'); // Recognize C escape sequences if specified
// * returns 5: "\\r\\a\\n"
// * example 6: addcslashes("\r\u0007\n", '\0'); // Do not recognize C escape sequences if not specified
// * returns 7: "\r\u0007\n"
var target = '',
chrs = [],
i = 0,
j = 0,
c = '',
next = '',
rangeBegin = '',
rangeEnd = '',
chr = '',
begin = 0,
end = 0,
octalLength = 0,
postOctalPos = 0,
cca = 0,
escHexGrp = [],
encoded = '',
percentHex = /%([\dA-Fa-f]+)/g;
var _pad = function (n, c) {
if ((n = n + '').length < c) {
return new Array(++c - n.length).join('0') + n;
}
return n;
};
for (i = 0; i < charlist.length; i++) {
c = charlist.charAt(i);
next = charlist.charAt(i + 1);
if (c === '\\' && next && (/\d/).test(next)) { // Octal
rangeBegin = charlist.slice(i + 1).match(/^\d+/)[0];
octalLength = rangeBegin.length;
postOctalPos = i + octalLength + 1;
if (charlist.charAt(postOctalPos) + charlist.charAt(postOctalPos + 1) === '..') { // Octal begins range
begin = rangeBegin.charCodeAt(0);
if ((/\\\d/).test(charlist.charAt(postOctalPos + 2) + charlist.charAt(postOctalPos + 3))) { // Range ends with octal
rangeEnd = charlist.slice(postOctalPos + 3).match(/^\d+/)[0];
i += 1; // Skip range end backslash
} else if (charlist.charAt(postOctalPos + 2)) { // Range ends with character
rangeEnd = charlist.charAt(postOctalPos + 2);
} else {
throw 'Range with no end point';
}
end = rangeEnd.charCodeAt(0);
if (end > begin) { // Treat as a range
for (j = begin; j <= end; j++) {
chrs.push(String.fromCharCode(j));
}
} else { // Supposed to treat period, begin and end as individual characters only, not a range
chrs.push('.', rangeBegin, rangeEnd);
}
i += rangeEnd.length + 2; // Skip dots and range end (already skipped range end backslash if present)
} else { // Octal is by itself
chr = String.fromCharCode(parseInt(rangeBegin, 8));
chrs.push(chr);
}
i += octalLength; // Skip range begin
} else if (next + charlist.charAt(i + 2) === '..') { // Character begins range
rangeBegin = c;
begin = rangeBegin.charCodeAt(0);
if ((/\\\d/).test(charlist.charAt(i + 3) + charlist.charAt(i + 4))) { // Range ends with octal
rangeEnd = charlist.slice(i + 4).match(/^\d+/)[0];
i += 1; // Skip range end backslash
} else if (charlist.charAt(i + 3)) { // Range ends with character
rangeEnd = charlist.charAt(i + 3);
} else {
throw 'Range with no end point';
}
end = rangeEnd.charCodeAt(0);
if (end > begin) { // Treat as a range
for (j = begin; j <= end; j++) {
chrs.push(String.fromCharCode(j));
}
} else { // Supposed to treat period, begin and end as individual characters only, not a range
chrs.push('.', rangeBegin, rangeEnd);
}
i += rangeEnd.length + 2; // Skip dots and range end (already skipped range end backslash if present)
} else { // Character is by itself
chrs.push(c);
}
}
for (i = 0; i < str.length; i++) {
c = str.charAt(i);
if (chrs.indexOf(c) !== -1) {
target += '\\';
cca = c.charCodeAt(0);
if (cca < 32 || cca > 126) { // Needs special escaping
switch (c) {
case '\n':
target += 'n';
break;
case '\t':
target += 't';
break;
case '\u000D':
target += 'r';
break;
case '\u0007':
target += 'a';
break;
case '\v':
target += 'v';
break;
case '\b':
target += 'b';
break;
case '\f':
target += 'f';
break;
default:
//target += _pad(cca.toString(8), 3);break; // Sufficient for UTF-16
encoded = encodeURIComponent(c);
// 3-length-padded UTF-8 octets
if ((escHexGrp = percentHex.exec(encoded)) !== null) {
target += _pad(parseInt(escHexGrp[1], 16).toString(8), 3); // already added a slash above
}
while ((escHexGrp = percentHex.exec(encoded)) !== null) {
target += '\\' + _pad(parseInt(escHexGrp[1], 16).toString(8), 3);
}
break;
}
} else { // Perform regular backslashed escaping
target += c;
}
} else { // Just add the character unescaped
target += c;
}
}
return target;
}
Example 1
addcslashes('foo[ ]', 'A..z'); // Escape all ASCII within capital A to lower z range, including square brackets
Should return
"\\f\\o\\o\\[ \\]"
Example 2
addcslashes("zoo['.']", 'z..A'); // Only escape z, period, and A here since not a lower-to-higher range
Should return
"\\zoo['\\.']"
Example 3
addcslashes("@a\u0000\u0010\u00A9", "\0..\37!@\177..\377") == '\\@a\\000\\020\\302\\251'); // Escape as octals those specified and less than 32 (0x20) or greater than 126 (0x7E), but not otherwise
Should return
true