1 files changed, 36 insertions, 0 deletions
diff --git a/utils/wordwrap.c b/utils/wordwrap.c
new file mode 100644
index 00000000..330b6a03
--- /dev/null
+++ b/utils/wordwrap.c
@@ -0,0 +1,36 @@
+/*
+ * Function to wrap text to a fixed number of columns.
+ *
+ * Currently, assumes the text is in a single-byte character set,
+ * because it's only used to display host key prompt messages.
+ * Extending to Unicode and using wcwidth() could be an extension.
+ */
+
+#include "misc.h"
+
+void wordwrap(BinarySink *bs, ptrlen input, size_t maxwid)
+{
+    size_t col = 0;
+    while (true) {
+        ptrlen word = ptrlen_get_word(&input, " ");
+        if (!word.len)
+            break;
+
+        /* At the start of a line, any word is legal, even if it's
+         * overlong, because we have to display it _somehow_ and
+         * wrapping to the next line won't make it any better. */
+        if (col > 0) {
+            size_t newcol = col + 1 + word.len;
+            if (newcol <= maxwid) {
+                put_byte(bs, ' ');
+                col++;
+            } else {
+                put_byte(bs, '\n');
+                col = 0;
+            }
+        }
+
+        put_datapl(bs, word);
+        col += word.len;
+    }
+}