From: Karel Zak <kzak@redhat.com>
Date: Tue, 19 Sep 2023 09:15:15 +0000 (+0200)
Subject: libsmartcols: Add --highlight option to filter sample
X-Git-Tag: v2.40-rc1~151^2~61
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1db278f95fdc4916a57f038a60e0ef980a1eb57e;p=thirdparty%2Futil-linux.git

libsmartcols: Add --highlight option to filter sample

This commit demonstrates another example of how to use the filter. It
also enables testing of two filters for the same table to ensure that
Bison and Flex generate a reentrant parser.

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

diff --git a/libsmartcols/samples/filter.c b/libsmartcols/samples/filter.c
index ceba8be582..5d9617a754 100644
--- a/libsmartcols/samples/filter.c
+++ b/libsmartcols/samples/filter.c
@@ -87,19 +87,59 @@ fail:
 	err(EXIT_FAILURE, "failed to create output line");
 }
 
+static struct libscols_filter *init_filter(struct libscols_table *tb, const char *query, int dump)
+{
+	struct libscols_iter *itr;
+	struct libscols_filter *f = scols_new_filter(NULL);
+	const char *name = NULL;
+	int rc = 0;
+
+	if (!f)
+		err(EXIT_FAILURE, "failed to allocate filter");
+	if (scols_filter_parse_string(f, query) != 0)
+		errx(EXIT_FAILURE, "failed to parse filter: %s",
+				scols_filter_get_errmsg(f));
+
+	itr = scols_new_iter(SCOLS_ITER_FORWARD);
+	if (!itr)
+		err(EXIT_FAILURE, "failed to allocate iterator");
+
+	while (scols_filter_next_holder(f, itr, &name, 0) == 0) {
+		struct libscols_column *col;
+
+		col = scols_table_get_column_by_name(tb, name);
+		if (!col) {
+			warnx("unknown column '%s' in filter", name);
+			rc++;
+			continue;
+		}
+		scols_filter_assign_column(f, itr, name, col);
+	}
+
+	scols_free_iter(itr);
+	if (dump)
+		scols_dump_filter(f, stdout);
+	if (rc) {
+		scols_unref_filter(f);
+		f = NULL;
+	}
+	return f;
+}
+
 int main(int argc, char *argv[])
 {
 	struct libscols_table *tb;
-	struct libscols_filter *fltr = NULL;
-	struct libscols_iter *itr = NULL;
+	struct libscols_filter *fltr = NULL, *hlight = NULL;
 	int c, i, json = 0, dump = 0;
 	int rc = 0;
+	char *f_query = NULL, *h_query = NULL;
 
 	static const struct option longopts[] = {
-		{ "json",   0, NULL, 'J' },
-		{ "dump",   0, NULL, 'D' },
-		{ "filter", 1, NULL, 'Q' },
-		{ "help",   0, NULL, 'h' },
+		{ "json",      0, NULL, 'J' },
+		{ "dump",      0, NULL, 'D' },
+		{ "filter",    1, NULL, 'Q' },
+		{ "highlight", 1, NULL, 'H' },
+		{ "help",      0, NULL, 'h' },
 		{ NULL, 0, NULL, 0 },
 	};
 
@@ -111,7 +151,7 @@ int main(int argc, char *argv[])
 	if (!tb)
 		err(EXIT_FAILURE, "failed to create output table");
 
-	while((c = getopt_long(argc, argv, "DhJQ:", longopts, NULL)) != -1) {
+	while((c = getopt_long(argc, argv, "H:DhJQ:", longopts, NULL)) != -1) {
 		switch(c) {
 		case 'h':
 			printf("%s --help | --filter | --dump | --json]\n", program_invocation_short_name);
@@ -123,63 +163,55 @@ int main(int argc, char *argv[])
 			json = 1;
 			break;
 		case 'Q':
-			fltr = scols_new_filter(NULL);
-			if (!fltr)
-				err(EXIT_FAILURE, "failed to allocate filter");
-			if (scols_filter_parse_string(fltr, optarg) != 0)
-				errx(EXIT_FAILURE, "failed to parse filter: %s",
-						scols_filter_get_errmsg(fltr));
+			f_query = optarg;
+			break;
+		case 'H':
+			h_query = optarg;
 			break;
 		}
 	}
 
-	if (dump && fltr)
-		scols_dump_filter(fltr, stdout);
-
 	scols_table_enable_json(tb, json);
 	setup_columns(tb);
 
-	if (fltr) {
-		const char *name = NULL;
-
-		itr = scols_new_iter(SCOLS_ITER_FORWARD);
-		if (!itr)
-			err(EXIT_FAILURE, "failed to allocate iterator");
-
-		while (scols_filter_next_holder(fltr, itr, &name, 0) == 0) {
-			struct libscols_column *col =
-					scols_table_get_column_by_name(tb, name);
-			if (!col) {
-				warnx("unknown column '%s' in filter", name);
-				rc++;
-				continue;
-			}
-			scols_filter_assign_column(fltr, itr, name, col);
-		}
-		if (rc)
+	if (f_query) {
+		fltr = init_filter(tb, f_query, dump);
+		if (!fltr)
+			goto done;
+	}
+	if (h_query) {
+		hlight = init_filter(tb, h_query, dump);
+		if (!hlight)
 			goto done;
+		scols_table_enable_colors(tb, isatty(STDOUT_FILENO));
 	}
 
 	for (i = 0; i < 10; i++) {
 		struct libscols_line *ln = add_line(tb, i + 1, i % 4);
 		int rc, status = 0;
 
-		if (!fltr)
-			continue;
-		rc = scols_line_apply_filter(ln, fltr, &status);
-		if (rc)
-			goto done;
-		if (status == 0) /* false */
-			scols_table_remove_line(tb, ln);
+		if (fltr) {
+			rc = scols_line_apply_filter(ln, fltr, &status);
+			if (rc)
+				goto done;
+			if (status == 0) {
+				scols_table_remove_line(tb, ln);
+				continue;
+			}
+		}
+		if (hlight) {
+			rc = scols_line_apply_filter(ln, hlight, &status);
+			if (rc)
+				goto done;
+			if (status)
+				scols_line_set_color(ln, "red");
+		}
 	}
 
 	scols_print_table(tb);
 done:
-	if (dump && fltr)
-		scols_dump_filter(fltr, stdout);
-
 	scols_unref_table(tb);
 	scols_unref_filter(fltr);
-	scols_free_iter(itr);
+	scols_unref_filter(hlight);
 	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
 }