Added gnu_regex2.c

gnu_regex2.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <regex.h>
+
+int main() {
+    regex_t regex;
+
+    regcomp(&regex, "(pattern) (example)", REG_EXTENDED);
+
+    char test_str[] = "This is a pattern example.";
+    regmatch_t pmatch[3]; // One for the whole match, and one for each group
+
+    if (regexec(&regex, test_str, 3, pmatch, 0) == 0) {
+        printf("Whole match: %.*s\n", pmatch[0].rm_eo - pmatch[0].rm_so, test_str + pmatch[0].rm_so);
+        printf("Group 1: %.*s\n", pmatch[1].rm_eo - pmatch[1].rm_so, test_str + pmatch[1].rm_so);
+        printf("Group 2: %.*s\n", pmatch[2].rm_eo - pmatch[2].rm_so, test_str + pmatch[2].rm_so);
+    } else {
+        printf("Pattern not found.\n");
+    }
+
+    regfree(&regex);
+
+    return 0;
+}