Backported xs_regex.h from xs.

xs_openssl.h

@@ -194,7 +194,7 @@ d_char *xs_evp_sign(char *secret, char *mem, int size)
 
     /* I've learnt all these magical incantations by watching
        the Python module code and the OpenSSL manual pages */
-    /* Well, "learnt" may be an exaggeration */
+    /* Well, "learnt" may be an overstatement */
 
     md = EVP_get_digestbyname("sha256");
 

xs_regex.h

@@ -0,0 +1,47 @@
+/* copyright (c) 2022 grunfink - MIT license */
+
+#ifndef _XS_REGEX_H
+
+#define _XS_REGEX_H
+
+d_char *xs_regex_match(char *str, char *rx, int count);
+#define xs_regex_matchall(str, rx) xs_regex_match(str, rx, 0xfffffff)
+
+#ifdef XS_IMPLEMENTATION
+
+#include <regex.h>
+
+d_char *xs_regex_match(char *str, char *rx, int count)
+/* returns a list with upto count matches */
+{
+    regex_t re;
+    regmatch_t rm;
+    d_char *list = NULL;
+    int offset = 0;
+    char *p;
+
+    if (regcomp(&re, rx, REG_EXTENDED))
+        return NULL;
+
+    list = xs_list_new();
+
+    while (count > 0 && !regexec(&re, (p = str + offset), 1, &rm, offset > 0 ? REG_NOTBOL : 0)) {
+        /* add the first part */
+        list = xs_list_append_m(list, p + rm.rm_so, rm.rm_eo - rm.rm_so);
+
+        /* add the asciiz */
+        list = xs_str_cat(list, "");
+
+        offset += rm.rm_eo;
+
+        count--;
+    }
+
+    regfree(&re);
+
+    return list;
+}
+
+#endif /* XS_IMPLEMENTATION */
+
+#endif /* XS_REGEX_H */