Add diff-filter.

Makefile

@@ -1,3 +1,3 @@
-SUBDIR+=
+SUBDIR+=bin
 
 .include <bsd.subdir.mk>

Makefile.inc

@@ -0,0 +1,2 @@
+WARNS?=		6
+WFORMAT?=	1

bin/Makefile

@@ -0,0 +1,3 @@
+SUBDIR+=diff-filter
+
+.include <bsd.subdir.mk>

bin/Makefile.inc

@@ -0,0 +1,3 @@
+#
+
+.include "${.CURDIR}/../../Makefile.inc"

bin/diff-filter/Makefile

@@ -0,0 +1,4 @@
+PROG=	diff-filter
+MAN=
+
+.include "${.CURDIR}/../../mk/bsdplus.prog.mk"

bin/diff-filter/diff-filter.c

@@ -0,0 +1,176 @@
+#include <err.h>
+#include <errno.h>
+#include <regex.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+enum rule_type {
+	AllowRule,
+	DenyRule,
+};
+
+struct rule {
+	enum rule_type r_type;
+	regex_t r_regex;
+	struct rule *r_next;
+};
+
+static int diff_filter(FILE *, enum rule_type, struct rule *);
+static int diff_filter_file(const char *, enum rule_type, struct rule *);
+static struct rule *rule_add(struct rule *, enum rule_type, const char *);
+static enum rule_type rules_run(const char *, enum rule_type, struct rule *);
+static void usage(void);
+
+int
+main(int argc, char *argv[])
+{
+	enum rule_type default_rule;
+	struct rule *rules;
+	const char *file;
+	int error;
+	int ch;
+
+	default_rule = AllowRule;
+	rules = NULL;
+
+	while ((ch = getopt(argc, argv, "ADa:d:")) != -1) {
+		switch (ch) {
+		case 'A':
+			default_rule = AllowRule;
+			break;
+		case 'D':
+			default_rule = DenyRule;
+			break;
+		case 'a':
+			rules = rule_add(rules, AllowRule, optarg);
+			break;
+		case 'd':
+			rules = rule_add(rules, DenyRule, optarg);
+			break;
+		default:
+			usage();
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc == 0) {
+		error = diff_filter(stdin, default_rule, rules);
+		if (error != 0)
+			errc(1, error, "diff_filter");
+	} else {
+		int errors;
+
+		errors = 0;
+
+		while (argc--) {
+			file = *argv++;
+			error = diff_filter_file(file, default_rule, rules);
+			if (error != 0) {
+				warnc(error, "diff_filter(%s)", file);
+				errors++;
+			}
+		}
+		if (errors > 0)
+			errx(1, "%u files had errors", errors);
+	}
+
+	return (0);
+}
+
+static int
+diff_filter(FILE *file, enum rule_type default_rule, struct rule *rules)
+{
+	enum rule_type state;
+	char *line;
+	size_t len;
+
+	state = default_rule;
+
+	while ((line = fgetln(file, &len)) != NULL) {
+		if (len == 0)
+			continue;
+		line[len - 1] = '\0';
+
+		if (strncmp(line, "Index: ", 7) == 0)
+			state = rules_run(line + 7, default_rule, rules);
+
+		if (state == AllowRule)
+			fprintf(stdout, "%s\n", line);
+	}
+	if (ferror(file)) {
+		if (errno == 0)
+			return (EIO);
+		return (errno);
+	}
+
+	return (0);
+}
+
+static int
+diff_filter_file(const char *name, enum rule_type default_rule, struct rule *rules)
+{
+	FILE *file;
+	int error;
+
+	file = fopen(name, "r");
+	if (file == NULL)
+		return (errno);
+
+	error = diff_filter(file, default_rule, rules);
+
+	fclose(file);
+
+	return (error);
+}
+
+static struct rule *
+rule_add(struct rule *rules, enum rule_type type, const char *string)
+{
+	struct rule *rule;
+	int rv;
+
+	rule = malloc(sizeof *rule);
+	rule->r_type = type;
+	rule->r_next = NULL;
+
+	rv = regcomp(&rule->r_regex, string, REG_NOSUB | REG_EXTENDED);
+	if (rv != 0)
+		err(1, "couldn't compile regex \"%s\"", string);
+
+	if (rules == NULL)
+		return (rule);
+
+	while (rules->r_next != NULL)
+		rules = rules->r_next;
+	rules->r_next = rule;
+	return (rules);
+}
+
+static enum rule_type
+rules_run(const char *line, enum rule_type default_rule, struct rule *rules)
+{
+	struct rule *rule;
+	int rv;
+
+	for (rule = rules; rule != NULL; rule = rule->r_next) {
+		rv = regexec(&rule->r_regex, line, 0, NULL, 0);
+		if (rv == 0)
+			return (rule->r_type);
+		if (rv == REG_NOMATCH)
+			continue;
+		errx(1, "regexec failed: %d", rv);
+	}
+
+	return (default_rule);
+}
+
+static void
+usage(void)
+{
+	fprintf(stderr,
+"diff-filter [-A | -D] [-a allow_regex] [-d deny_regex] file ...\n");
+	exit(1);
+}

mk/bsdplus.prog.mk

@@ -0,0 +1,6 @@
+.include <bsd.prog.mk>
+
+OSNAME!=uname
+.if ${OSNAME} == "Darwin"
+CFLAGS:=${CFLAGS:N-Wsystem-headers}
+.endif