libsmartcols: add scols_table_print_range()

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

1 files changed, 35 insertions, 12 deletions

diff --git a/libsmartcols/samples/tree.c b/libsmartcols/samples/tree.c
index 52be7fbd5..d2afc4717 100644
--- a/libsmartcols/samples/tree.c
+++ b/libsmartcols/samples/tree.c
@@ -142,13 +142,15 @@ static void add_lines(struct libscols_table *tb, const char *dirname)
 static void __attribute__((__noreturn__)) usage(FILE *out)
 {
 	fprintf(out, " %s [options] [<dir> ...]\n\n", program_invocation_short_name);
-	fputs(" -c, --csv            display a csv-like output\n", out);
-	fputs(" -i, --ascii          use ascii characters only\n", out);
-	fputs(" -l, --list           use list format output\n", out);
-	fputs(" -n, --noheadings     don't print headings\n", out);
-	fputs(" -p, --pairs          use key=\"value\" output format\n", out);
-	fputs(" -J, --json           use JSON output format\n", out);
-	fputs(" -r, --raw            use raw output format\n", out);
+	fputs(" -c, --csv               display a csv-like output\n", out);
+	fputs(" -i, --ascii             use ascii characters only\n", out);
+	fputs(" -l, --list              use list format output\n", out);
+	fputs(" -n, --noheadings        don't print headings\n", out);
+	fputs(" -p, --pairs             use key=\"value\" output format\n", out);
+	fputs(" -J, --json              use JSON output format\n", out);
+	fputs(" -r, --raw               use raw output format\n", out);
+	fputs(" -S, --range-start <n>   first line to print\n", out);
+	fputs(" -E, --range-end <n>     last line to print\n", out);
 
 	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
@@ -156,7 +158,8 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
 int main(int argc, char *argv[])
 {
 	struct libscols_table *tb;
-	int c, notree = 0;
+	int c, notree = 0, nstart = -1, nend = -1;
+
 
 	static const struct option longopts[] = {
 		{ "ascii",	0, 0, 'i' },
@@ -166,7 +169,8 @@ int main(int argc, char *argv[])
 		{ "pairs",      0, 0, 'p' },
 		{ "json",       0, 0, 'J' },
 		{ "raw",        0, 0, 'r' },
-
+		{ "range-start",1, 0, 'S' },
+		{ "range-end",  1, 0, 'E' },
 		{ NULL, 0, 0, 0 },
 	};
 
@@ -178,7 +182,7 @@ int main(int argc, char *argv[])
 	if (!tb)
 		err(EXIT_FAILURE, "faild to create output table");
 
-	while((c = getopt_long(argc, argv, "ciJlnpr", longopts, NULL)) != -1) {
+	while((c = getopt_long(argc, argv, "ciJlnprS:E:", longopts, NULL)) != -1) {
 		switch(c) {
 		case 'c':
 			scols_table_set_column_separator(tb, ",");
@@ -206,6 +210,12 @@ int main(int argc, char *argv[])
 			scols_table_enable_raw(tb, 1);
 			notree = 1;
 			break;
+		case 'S':
+			nstart = strtos32_or_err(optarg, "failed to parse range start") - 1;
+			break;
+		case 'E':
+			nend = strtos32_or_err(optarg, "failed to parse range end") - 1;
+			break;
 		default:
 			usage(stderr);
 		}
@@ -219,8 +229,21 @@ int main(int argc, char *argv[])
 	else while (optind < argc)
 		add_lines(tb, argv[optind++]);
 
-	scols_print_table(tb);
-	scols_unref_table(tb);
+	if (nstart >= 0 || nend >= 0) {
+		/* print subset */
+		struct libscols_line *start = NULL, *end = NULL;
+
+		if (nstart >= 0)
+			start = scols_table_get_line(tb, nstart);
+		if (nend >= 0)
+			end = scols_table_get_line(tb, nend);
 
+		if (start || end)
+			scols_table_print_range(tb, start, end);
+	} else
+		/* print all table */
+		scols_print_table(tb);
+
+	scols_unref_table(tb);
 	return EXIT_SUCCESS;
 }