From 1a0f614dd29f8666647e005c63ae00b3638234d4 Mon Sep 17 00:00:00 2001
From: Quentin Young <qlyoung@cumulusnetworks.com>
Date: Wed, 12 Jul 2017 14:40:18 -0400
Subject: [PATCH] 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>
---
 lib/command.c | 35 +++++++++++++++++++++++++++++++++++
 lib/command.h |  1 +
 lib/vty.c     | 14 +++++---------
 vtysh/vtysh.c | 17 ++++++++---------
 4 files changed, 49 insertions(+), 18 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)
 {
diff --git a/lib/command.h b/lib/command.h
index 927c04006c..781387b5e6 100644
--- a/lib/command.h
+++ b/lib/command.h
@@ -404,5 +404,6 @@ struct cmd_variable_handler {
 
 extern void cmd_variable_complete (struct cmd_token *token, const char *arg, vector comps);
 extern void cmd_variable_handler_register (const struct cmd_variable_handler *cvh);
+extern char *cmd_variable_comp2str (vector comps, unsigned short cols, const char nl[]);
 
 #endif /* _ZEBRA_COMMAND_H */
diff --git a/lib/vty.c b/lib/vty.c
index e6497b3100..dd8dac74b6 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -1134,17 +1134,13 @@ vty_describe_command (struct vty *vty)
             vector varcomps = vector_init (VECTOR_MIN_SIZE);
             cmd_variable_complete (token, ref, varcomps);
 
-            if (vector_active(varcomps) > 0)
+            if (vector_active (varcomps) > 0)
               {
-                vty_out(vty, "     ");
-                for (size_t j = 0; j < vector_active (varcomps); j++)
-                  {
-                    char *item = vector_slot (varcomps, j);
-                    vty_out(vty, " %s", item);
-                    XFREE(MTYPE_COMPLETION, item);
-                  }
-                vty_out (vty, VTYNL);
+                char *ac = cmd_variable_comp2str(varcomps, vty->width, VTYNL);
+                vty_outln(vty, "%s", ac);
+                XFREE(MTYPE_TMP, ac);
               }
+
             vector_free(varcomps);
           }
 #if 0
diff --git a/vtysh/vtysh.c b/vtysh/vtysh.c
index f02bd0c888..7df02e19ce 100644
--- a/vtysh/vtysh.c
+++ b/vtysh/vtysh.c
@@ -771,7 +771,7 @@ vtysh_rl_describe (void)
       rl_on_new_line ();
       return 0;
       break;
-    }  
+    }
 
   /* Get width of command string. */
   width = 0;
@@ -808,15 +808,14 @@ vtysh_rl_describe (void)
 
             if (vector_active (varcomps) > 0)
               {
-                fprintf(stdout, "     ");
-                for (size_t j = 0; j < vector_active (varcomps); j++)
-                  {
-                    char *item = vector_slot (varcomps, j);
-                    fprintf (stdout, " %s", item);
-                    XFREE (MTYPE_COMPLETION, item);
-                  }
-                vty_out (vty, VTYNL);
+                int rows, cols;
+                rl_get_screen_size(&rows, &cols);
+
+                char *ac = cmd_variable_comp2str(varcomps, cols, "\n");
+                fprintf(stdout, "%s\n", ac);
+                XFREE(MTYPE_TMP, ac);
               }
+
             vector_free (varcomps);
           }
       }
-- 
2.39.5