libsmartcols: add sample-scols-continuous

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

libsmartcols/samples/Makemodule.am

@@ -2,7 +2,8 @@
 check_PROGRAMS += \
 	sample-scols-tree \
 	sample-scols-title \
-	sample-scols-wrap
+	sample-scols-wrap \
+	sample-scols-continuous
 
 sample_scols_tree_SOURCES = libsmartcols/samples/tree.c
 sample_scols_tree_LDADD = libsmartcols.la libcommon.la
@@ -15,3 +16,8 @@ sample_scols_title_CFLAGS = -I$(ul_libsmartcols_incdir)
 sample_scols_wrap_SOURCES = libsmartcols/samples/wrap.c
 sample_scols_wrap_LDADD = libsmartcols.la
 sample_scols_wrap_CFLAGS = -I$(ul_libsmartcols_incdir)
+
+sample_scols_continuous_SOURCES = libsmartcols/samples/continuous.c
+sample_scols_continuous_LDADD = libsmartcols.la libcommon.la
+sample_scols_continuous_CFLAGS = -I$(ul_libsmartcols_incdir)
+

libsmartcols/samples/continuous.c

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2016 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ */
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+#include "c.h"
+#include "nls.h"
+#include "strutils.h"
+#include "xalloc.h"
+
+#include "libsmartcols.h"
+
+#define TIME_PERIOD	3.0	/* seconds */
+
+enum { COL_NUM, COL_DATA, COL_TIME };
+
+static double time_diff(struct timeval *a, struct timeval *b)
+{
+	return (a->tv_sec - b->tv_sec) + (a->tv_usec - b->tv_usec) / 1E6;
+}
+
+/* add columns to the @tb */
+static void setup_columns(struct libscols_table *tb)
+{
+	if (!scols_table_new_column(tb, "#NUM", 0, SCOLS_FL_RIGHT))
+		goto fail;
+	if (!scols_table_new_column(tb, "DATA", 0, 0))
+		goto fail;
+	if (!scols_table_new_column(tb, "TIME", 0, 0))
+		goto fail;
+	return;
+fail:
+	scols_unref_table(tb);
+	err(EXIT_FAILURE, "faild to create output columns");
+}
+
+static struct libscols_line *add_line(struct libscols_table *tb, size_t i)
+{
+	char *p;
+	struct libscols_line *ln = scols_table_new_line(tb, NULL);
+
+	if (!ln)
+		err(EXIT_FAILURE, "failed to create output line");
+
+	xasprintf(&p, "%zu", i);
+	if (scols_line_refer_data(ln, COL_NUM, p))
+		goto fail;
+
+	xasprintf(&p, "data-%02zu-%02zu-%02zu-end", i + 1, i + 2, i + 3);
+	if (scols_line_refer_data(ln, COL_DATA, p))
+		goto fail;
+
+	return ln;
+fail:
+	scols_unref_table(tb);
+	err(EXIT_FAILURE, "faild to create output line");
+}
+
+int main(int argc, char *argv[])
+{
+	struct libscols_table *tb;
+	size_t i;
+	struct timeval last;
+
+	scols_init_debug(0);
+
+	tb = scols_new_table();
+	if (!tb)
+		err(EXIT_FAILURE, "faild to create output table");
+
+	setup_columns(tb);
+	gettimeofday(&last, NULL);
+
+	for (i = 0; i < 10; i++) {
+		struct libscols_line *line;
+		struct timeval now;
+		int done = 0;
+		char *timecell = xmalloc( sizeof(stringify_value(UINT_MAX)) );
+
+		line = add_line(tb, i);
+
+		/* Make a reference from cell data to the buffer, then we can
+		 * update cell data without any interaction with libsmartcols
+		 */
+		scols_line_refer_data(line, COL_TIME, timecell);
+
+		do {
+			double diff;
+
+			gettimeofday(&now, NULL);
+			diff = time_diff(&now, &last);
+
+			if (now.tv_sec == last.tv_sec + (long) TIME_PERIOD)
+				done = 1;
+			else
+				xusleep(100000);
+
+			/* update "TIME" cell data */
+			sprintf(timecell, "%f [%3d%%]", diff,
+				done ? 100 : (int)(diff / (TIME_PERIOD / 100.0)));
+
+			/* don't print line separator when in progress */
+			scols_table_enable_nolinesep(tb, !done);
+			/* print the line */
+			scols_table_print_range(tb, line, NULL);
+
+			if (!done) {
+				/* terminal is waiting for \n, fflush() to force output */
+				fflush(scols_table_get_stream(tb));
+				/* move to the begin of the line */
+				fputc('\r', scols_table_get_stream(tb));
+			}
+		} while (!done);
+
+		last = now;
+	}
+
+	scols_unref_table(tb);
+	return EXIT_SUCCESS;
+}