1 files changed, 83 insertions, 9 deletions

diff --git a/util.c b/util.c
index e210e34..439bcf7 100644
--- a/util.c
+++ b/util.c
@@ -2,6 +2,7 @@
 #include <arpa/inet.h>
 #include <stdlib.h>
 
+#include <string.h>
 #include <stdio.h>
 #include <errno.h>
 #include <regex.h>
@@ -23,26 +24,99 @@ void herr(int output, const char* funcName) {
 	}
 }
 
-sds gsub(const sds str, const char* regex, const char* repl) {
-	regex_t preg;
-	regcomp(&preg, regex, 0);
+sds getMatch(const sds str, const regmatch_t match) {
+	return sdsnewlen(str + match.rm_so, match.rm_eo - match.rm_so);
+}
+int validMatch(const regmatch_t match) {
+	return match.rm_so > -1;
+}
 
-	int strInd = 0;
-	regmatch_t pmatch[1] = {
+void resizeMatches(int* *matches, int* size) {
+	if (*size == 0) {
+		*matches = malloc((*size = 8) * sizeof(int*));
+		return;
+	}
+
+	int* *biggerArr = malloc((*size * 2) * sizeof(int*));
+	for (size_t i = 0; i < *size; i++) {
+		biggerArr[i] = matches[i];
+	}
+	*size *= 2;
+	free(matches);
+	*matches = *biggerArr;
+}
+void pushBackMatch(int* *matches, int *matchesCount, int *matchesSize, int matchStart) {
+	if (*matchesCount >= *matchesSize)
+		resizeMatches(matches, matchesSize);
+
+	(*matches)[*matchesCount] = matchStart;
+	*matchesCount += 1;
+}
+
+#define MATCHSTART str + strInd
+sds gsub_getm(sds str, const regex_t *regex, const char* repl, int* *matches, int *matchesCount) {
+	regmatch_t pmatch[10] = {
+		{ .rm_so = 0, .rm_eo = 0, }, { .rm_so = 0, .rm_eo = 0, }, { .rm_so = 0, .rm_eo = 0, },
+		{ .rm_so = 0, .rm_eo = 0, }, { .rm_so = 0, .rm_eo = 0, }, { .rm_so = 0, .rm_eo = 0, },
+		{ .rm_so = 0, .rm_eo = 0, }, { .rm_so = 0, .rm_eo = 0, }, { .rm_so = 0, .rm_eo = 0, },
 		{ .rm_so = 0, .rm_eo = 0, },
 	};
 
+	int strInd = 0;
+	int matchesSize = (matchesCount != NULL) ? *matchesCount : 0;
+	size_t replLen = strlen(repl);
+
 	sds ret = sdsempty();
 	// sdslen is in O(1) time
 	while (strInd < sdslen(str)) {
-		if (regexec(&preg, str + strInd, 1, pmatch, 0) > 0) {
-			ret = sdscat(ret, str + strInd);
+		/* If no matches were found, cat the entire string and stop trying */
+		if (regexec(regex, MATCHSTART, 10, pmatch, 0) != 0) {
+			ret = sdscat(ret, MATCHSTART);
 			break;
 		}
-		ret = sdscatlen(ret, str + strInd, pmatch[0].rm_so);
-		ret = sdscat(ret, repl);
+
+		/* Cat everything before the match */
+		ret = sdscatlen(ret, MATCHSTART, pmatch[0].rm_so);
+
+		/* Cat repl in place of the match */
+		for(size_t i = 0; i < replLen; i++) {
+			if (repl[i] <= '\10') {
+			if (pmatch[repl[i] % 10].rm_so > -1)
+				ret = sdscatsds(ret, getMatch(MATCHSTART, pmatch[repl[i] % 10]));
+			}
+			else
+				ret = sdscatlen(ret, &repl[i], 1);
+		}
+
+		/* Add current match to matches array */
+		if (matchesCount != NULL) {
+			pushBackMatch(matches, matchesCount, &matchesSize, strInd + pmatch[0].rm_so);
+		}
+
+		/* Continute after the current match */
 		strInd += pmatch[0].rm_eo;
 	}
 
+	sdsfree(str);
 	return ret;
 }
+
+sds gsub(sds str, const regex_t* regex, const char* repl) {
+	return gsub_getm(str, regex, repl, NULL, NULL);
+}
+
+int digits(int num) {
+	if (num < 0) num *= -1;
+	// This is the fastest way to get the number of digits
+	if (num < 10) return 1;
+	if (num < 100) return 2;
+	if (num < 1000) return 3;
+	if (num < 10000) return 4;
+	if (num < 100000) return 5;
+	if (num < 1000000) return 6;
+	if (num < 10000000) return 7;
+	if (num < 100000000) return 8;
+	if (num < 1000000000) return 9;
+	//        2147483647 (2^31-1) is max value of int
+	return 10;
+}