lib, vtysh: pretty-print variable autocompletions

Pretty-prints variable autocompletions by breaking them up into multiple
lines, indenting them consistently and respecting the column width of
the terminal.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/lib/command.c b/lib/command.c
index 5ca4a0fda9..03918b7217 100644
--- a/lib/command.c
+++ b/lib/command.c
@@ -715,6 +715,41 @@ cmd_variable_complete (struct cmd_token *token, const char *arg, vector comps)
   vector_free(tmpcomps);
 }
 
+#define AUTOCOMP_INDENT 5
+
+char *
+cmd_variable_comp2str(vector comps, unsigned short cols, const char nl[])
+{
+  size_t bsz = 16;
+  char *buf = XCALLOC(MTYPE_TMP, bsz);
+  int lc = AUTOCOMP_INDENT;
+  size_t cs = AUTOCOMP_INDENT;
+  size_t nllen = strlen(nl);
+  size_t itemlen;
+  snprintf(buf, bsz, "%*s", AUTOCOMP_INDENT, "");
+  for (size_t j = 0; j < vector_active (comps); j++)
+    {
+      char *item = vector_slot (comps, j);
+      itemlen = strlen(item);
+
+      if (cs + itemlen + nllen + AUTOCOMP_INDENT + 2 >= bsz)
+        buf = XREALLOC(MTYPE_TMP, buf, (bsz *= 2));
+
+      if (lc + itemlen + 1 >= cols)
+        {
+          cs += snprintf(&buf[cs], bsz - cs, "%s%*s", nl, AUTOCOMP_INDENT, "");
+          lc = AUTOCOMP_INDENT;
+        }
+
+      size_t written = snprintf(&buf[cs], bsz - cs, "%s ", item);
+      lc += written;
+      cs += written;
+      XFREE (MTYPE_COMPLETION, item);
+      vector_set_index (comps, j, NULL);
+    }
+  return buf;
+}
+
 void
 cmd_variable_handler_register (const struct cmd_variable_handler *cvh)
 {