libsmartcols: add scols_table_enable_nowrap()

This allows to use libsmartcols in ncurses programs without any
additional voodoo.

Signed-off-by: Karel Zak <kzak@redhat.com>

libsmartcols/docs/libsmartcols-sections.txt

@@ -96,6 +96,7 @@ scols_table_enable_export
 scols_table_enable_json
 scols_table_enable_maxout
 scols_table_enable_noheadings
+scols_table_enable_nowrap
 scols_table_enable_raw
 scols_table_get_column
 scols_table_get_column_separator

libsmartcols/src/libsmartcols.h.in

@@ -189,6 +189,7 @@ extern int scols_table_enable_json(struct libscols_table *tb, int enable);
 extern int scols_table_enable_noheadings(struct libscols_table *tb, int enable);
 extern int scols_table_enable_export(struct libscols_table *tb, int enable);
 extern int scols_table_enable_maxout(struct libscols_table *tb, int enable);
+extern int scols_table_enable_nowrap(struct libscols_table *tb, int enable);
 
 extern int scols_table_set_column_separator(struct libscols_table *tb, const char *sep);
 extern int scols_table_set_line_separator(struct libscols_table *tb, const char *sep);

libsmartcols/src/libsmartcols.sym

@@ -120,3 +120,8 @@ global:
 	scols_table_is_json;
 	scols_table_set_name;
 } SMARTCOLS_2.25;
+
+SMARTCOLS_2.28 {
+global:
+	scols_table_enable_nowrap;
+} SMARTCOLS_2.27;

libsmartcols/src/smartcolsP.h

@@ -89,6 +89,8 @@ struct libscols_column {
 
 	struct libscols_cell	header;
 	struct list_head	cl_columns;
+
+	unsigned int ignore : 1;
 };
 
 /*
@@ -147,7 +149,8 @@ struct libscols_table {
 			colors_wanted	:1,	/* enable colors */
 			is_term		:1,	/* isatty() */
 			maxout		:1,	/* maximalize output */
-			no_headings	:1;	/* don't print header */
+			no_headings	:1,	/* don't print header */
+			no_wrap		:1;	/* never wrap lines */
 };
 
 #define IS_ITER_FORWARD(_i)	((_i)->direction == SCOLS_ITER_FORWARD)

libsmartcols/src/table.c

@@ -838,6 +838,24 @@ int scols_table_enable_maxout(struct libscols_table *tb, int enable)
 	return 0;
 }
 
+/**
+ * scols_table_enable_nowrap:
+ * @tb: table
+ * @enable: 1 or 0
+ *
+ * Never continue on next line, remove last column(s) when too large, truncate last column.
+ *
+ * Returns: 0 on success, negative number in case of an error.
+ */
+int scols_table_enable_nowrap(struct libscols_table *tb, int enable)
+{
+	if (!tb)
+		return -EINVAL;
+	DBG(TAB, ul_debugobj(tb, "nowrap: %s", enable ? "ENABLE" : "DISABLE"));
+	tb->no_wrap = enable ? 1 : 0;
+	return 0;
+}
+
 /**
  * scols_table_colors_wanted:
  * @tb: table

libsmartcols/src/table_print.c

@@ -176,8 +176,19 @@ static int line_ascii_art_to_buffer(struct libscols_table *tb,
 	return buffer_append_data(buf, art);
 }
 
-#define is_last_column(_tb, _cl) \
-		list_entry_is_last(&(_cl)->cl_columns, &(_tb)->tb_columns)
+static int is_last_column(struct libscols_table *tb, struct libscols_column *cl) 
+{
+	int rc = list_entry_is_last(&cl->cl_columns, &tb->tb_columns);
+	struct libscols_column *next;
+
+	if (rc)
+		return 1;
+
+	next = list_entry(cl->cl_columns.next, struct libscols_column, cl_columns);
+	if (next && next->ignore)
+		return 1;
+	return 0;
+}
 
 #define colsep(tb) ((tb)->colsep ? (tb)->colsep : " ")
 #define linesep(tb) ((tb)->linesep ? (tb)->linesep : "\n")
@@ -518,6 +529,8 @@ static int print_line(struct libscols_table *tb,
 
 	scols_reset_iter(&itr, SCOLS_ITER_FORWARD);
 	while (rc == 0 && scols_table_next_column(tb, &itr, &cl) == 0) {
+		if (cl->ignore)
+			continue;
 		rc = cell_to_buffer(tb, ln, cl, buf);
 		if (!rc)
 			rc = print_data(tb, cl, ln,
@@ -547,6 +560,8 @@ static int print_header(struct libscols_table *tb, struct libscols_buffer *buf)
 	/* set the width according to the size of the data */
 	scols_reset_iter(&itr, SCOLS_ITER_FORWARD);
 	while (rc == 0 && scols_table_next_column(tb, &itr, &cl) == 0) {
+		if (cl->ignore)
+			continue;
 		rc = buffer_set_data(buf, scols_cell_get_data(&cl->header));
 		if (!rc)
 			rc = print_data(tb, cl, NULL, &cl->header, buf);
@@ -642,9 +657,14 @@ static int print_tree(struct libscols_table *tb, struct libscols_buffer *buf)
 
 static void dbg_column(struct libscols_table *tb, struct libscols_column *cl)
 {
+	if (cl->ignore) {
+		DBG(COL, ul_debugobj(cl, "%s ignored", cl->header.data));
+		return;
+	}
+
 	DBG(COL, ul_debugobj(cl, "%15s seq=%zu, width=%zd, "
 				 "hint=%d, avg=%zu, max=%zu, min=%zu, "
-				 "extreme=%s",
+				 "extreme=%s %s",
 
 		cl->header.data, cl->seqnum, cl->width,
 		cl->width_hint > 1 ? (int) cl->width_hint :
@@ -652,7 +672,8 @@ static void dbg_column(struct libscols_table *tb, struct libscols_column *cl)
 		cl->width_avg,
 		cl->width_max,
 		cl->width_min,
-		cl->is_extreme ? "yes" : "not"));
+		cl->is_extreme ? "yes" : "not",
+		cl->flags & SCOLS_FL_TRUNC ? "trunc" : ""));
 }
 
 static void dbg_columns(struct libscols_table *tb)
@@ -766,7 +787,7 @@ static int recount_widths(struct libscols_table *tb, struct libscols_buffer *buf
 		if (rc)
 			goto done;
 
-		width += cl->width + (is_last_column(tb, cl) ? 0 : 1);
+		width += cl->width + (is_last_column(tb, cl) ? 0 : 1);	/* separator for non-last column */
 		extremes += cl->is_extreme;
 	}
 
@@ -910,6 +931,26 @@ static int recount_widths(struct libscols_table *tb, struct libscols_buffer *buf
 		}
 	}
 
+	/* ignore last column(s) or force last column to be truncated if
+	 * nowrap mode enabled */
+	if (tb->no_wrap && width > tb->termwidth) {
+		scols_reset_iter(&itr, SCOLS_ITER_BACKWARD);
+		while (scols_table_next_column(tb, &itr, &cl) == 0) {
+
+			if (width <= tb->termwidth)
+				break;
+			if (width - cl->width < tb->termwidth) {
+				size_t r =  width - tb->termwidth;
+
+				cl->flags |= SCOLS_FL_TRUNC;
+				cl->width -= r;
+				width -= r;
+			} else {
+				cl->ignore = 1;
+				width -= cl->width + 1;		/* +1 means separator between columns */
+			}
+		}
+	}
 done:
 	DBG(TAB, ul_debugobj(tb, "  final width: %zu (rc=%d)", width, rc));
 	ON_DBG(TAB, dbg_columns(tb));