lib/fold: Add text fold utility

[petitboot] / lib / fold / fold.c

diff --git a/lib/fold/fold.c b/lib/fold/fold.c
new file mode 100644 (file)
index 0000000..ec10c8c
--- /dev/null
+++ b/lib/fold/fold.c
@@ -0,0 +1,44 @@
+
+#include "fold/fold.h"
+
+void fold_text(const char *text,
+               int linelen,
+               int line_cb(void *arg, const char *start, int len),
+               void *arg)
+{
+       const char *start, *end, *sep;
+       int rc = 0;
+
+       start = end = sep = text;
+
+       while (!rc) {
+
+               if (*end == '\n') {
+                       rc = line_cb(arg, start, end - start);
+                       start = sep = ++end;
+
+               } else if (*end == '\0') {
+                       line_cb(arg, start, end - start);
+                       rc = 1;
+
+               } else if (end - start >= linelen - 1) {
+                       if (sep != start) {
+                               /* split on a previous word boundary, if
+                                * possible */
+                               rc = line_cb(arg, start, sep - start);
+                               start = end = ++sep;
+                       } else {
+                               /* otherwise, break the word */
+                               end++;
+                               rc = line_cb(arg, start, end - start);
+                               start = sep = end;
+                       }
+
+               } else {
+                       end++;
+                       /* record our last separator */
+                       if (*end == ' ')
+                               sep = end;
+               }
+       }
+}