1 files changed, 34 insertions, 0 deletions
diff --git a/utils/percent_encode.c b/utils/percent_encode.c
new file mode 100644
index 00000000..ea04b0ac
--- /dev/null
+++ b/utils/percent_encode.c
@@ -0,0 +1,34 @@
+/*
+ * %-encoding in URL style.
+ *
+ * Defaults to escaping % itself (necessary for decoding to even
+ * work), and any C0 escape character. Further bad characters can be
+ * provided in 'badchars'.
+ */
+
+#include "misc.h"
+
+void percent_encode_bs(BinarySink *bs, ptrlen data, const char *badchars)
+{
+    for (const char *p = data.ptr, *e = ptrlen_end(data); p < e; p++) {
+        char c = *p;
+        if (c == '%' || c < ' ' || (badchars && strchr(badchars, c)))
+            put_fmt(bs, "%%%02X", (unsigned char)c);
+        else
+            put_byte(bs, c);
+    }
+}
+
+void percent_encode_fp(FILE *fp, ptrlen data, const char *badchars)
+{
+    stdio_sink ss;
+    stdio_sink_init(&ss, fp);
+    percent_encode_bs(BinarySink_UPCAST(&ss), data, badchars);
+}
+
+strbuf *percent_encode_sb(ptrlen data, const char *badchars)
+{
+    strbuf *sb = strbuf_new();
+    percent_encode_bs(BinarySink_UPCAST(sb), data, badchars);
+    return sb;
+}