From b7830887ea34488b339c18ad89b49af085f4635a Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Tue, 19 Jul 2011 12:44:20 +0200
Subject: [PATCH] config: Implement conf_set_value_in_file()

---
 conf.c           | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
 conf.h           |  2 ++
 test/test_conf.c | 24 ++++++++++++++++++++++
 3 files changed, 78 insertions(+)

diff --git a/conf.c b/conf.c
index cd0b7c52c..383b1a803 100644
--- a/conf.c
+++ b/conf.c
@@ -550,3 +550,55 @@ conf_update_from_environment(struct conf *conf, char **errmsg)
 
 	return true;
 }
+
+bool
+conf_set_value_in_file(const char *path, const char *key, const char *value,
+                       char **errmsg)
+{
+	FILE *infile, *outfile;
+	char *outpath;
+	char buf[10000];
+	bool found;
+
+	infile = fopen(path, "r");
+	if (!infile) {
+		*errmsg = format("%s: %s", path, strerror(errno));
+		return false;
+	}
+
+	outpath = format("%s.tmp.%s", path, tmp_string());
+	outfile = fopen(outpath, "w");
+	if (!outfile) {
+		*errmsg = format("%s: %s", outpath, strerror(errno));
+		free(outpath);
+		fclose(infile);
+		return false;
+	}
+
+	found = false;
+	while (fgets(buf, sizeof(buf), infile)) {
+		char *errmsg2, *key2, *value2;
+		bool ok;
+		ok = parse_line(buf, &key2, &value2, &errmsg2);
+		if (ok && key2 && str_eq(key2, key)) {
+			found = true;
+			fprintf(outfile, "%s = %s\n", key, value);
+		} else {
+			fputs(buf, outfile);
+		}
+	}
+
+	if (!found) {
+		fprintf(outfile, "%s = %s\n", key, value);
+	}
+
+	fclose(infile);
+	fclose(outfile);
+	if (x_rename(outpath, path) != 0) {
+		*errmsg = format("rename %s to %s: %s", outpath, path, strerror(errno));
+		return false;
+	}
+	free(outpath);
+
+	return true;
+}
diff --git a/conf.h b/conf.h
index 0890b42bd..257faa966 100644
--- a/conf.h
+++ b/conf.h
@@ -36,5 +36,7 @@ struct conf *conf_create(void);
 void conf_free(struct conf *conf);
 bool conf_read(struct conf *conf, const char *path, char **errmsg);
 bool conf_update_from_environment(struct conf *conf, char **errmsg);
+bool conf_set_value_in_file(const char *path, const char *key,
+                            const char *value, char **errmsg);
 
 #endif
diff --git a/test/test_conf.c b/test/test_conf.c
index 548584831..4b6c09f87 100644
--- a/test/test_conf.c
+++ b/test/test_conf.c
@@ -302,4 +302,28 @@ TEST(conf_update_from_environment)
 	conf_free(conf);
 }
 
+TEST(conf_set_new_value)
+{
+	char *errmsg;
+	char *data;
+
+	create_file("ccache.conf", "flavour = vanilla\n");
+	CHECK(conf_set_value_in_file("ccache.conf", "topping", "chocolate", &errmsg));
+	data = read_text_file("ccache.conf", 0);
+	CHECK(data);
+	CHECK_STR_EQ_FREE2("flavour = vanilla\ntopping = chocolate\n", data);
+}
+
+TEST(conf_set_existing_value)
+{
+	char *errmsg;
+	char *data;
+
+	create_file("ccache.conf", "flavour = chocolate\ntopping = chocolate\n");
+	CHECK(conf_set_value_in_file("ccache.conf", "flavour", "vanilla", &errmsg));
+	data = read_text_file("ccache.conf", 0);
+	CHECK(data);
+	CHECK_STR_EQ_FREE2("flavour = vanilla\ntopping = chocolate\n", data);
+}
+
 TEST_SUITE_END
-- 
2.47.3