Use a static buffer for base directory paths

chat.h

@@ -294,12 +294,8 @@ void logFormat(uint id, const time_t *time, const char *format, ...)
 	__attribute__((format(printf, 3, 4)));
 void logClose(void);
 
-const char *configPath(
+const char *configPath(const char **dirs, const char *path);
-	char *buf, size_t cap, const char **dirs, const char *path
+const char *dataPath(const char **dirs, const char *path);
-);
-const char *dataPath(
-	char *buf, size_t cap, const char **dirs, const char *path
-);
 FILE *configOpen(const char *path, const char *mode);
 FILE *dataOpen(const char *path, const char *mode);
 void dataMkdir(const char *path);

irc.c

@@ -27,7 +27,6 @@
 
 #include <assert.h>
 #include <err.h>
-#include <limits.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <stdarg.h>
@@ -61,12 +60,9 @@ void ircConfig(bool insecure, const char *cert, const char *priv) {
 		tls_config_insecure_noverifyname(config);
 	}
 
-	const char *path;
-	const char *dirs;
-	char buf[PATH_MAX];
 	if (cert) {
-		dirs = NULL;
+		const char *dirs = NULL;
-		while (NULL != (path = configPath(buf, sizeof(buf), &dirs, cert))) {
+		for (const char *path; NULL != (path = configPath(&dirs, cert));) {
 			if (priv) {
 				error = tls_config_set_cert_file(config, path);
 			} else {
@@ -77,8 +73,8 @@ void ircConfig(bool insecure, const char *cert, const char *priv) {
 		if (error) errx(EX_NOINPUT, "%s: %s", cert, tls_config_error(config));
 	}
 	if (priv) {
-		dirs = NULL;
+		const char *dirs = NULL;
-		while (NULL != (path = configPath(buf, sizeof(buf), &dirs, priv))) {
+		for (const char *path; NULL != (path = configPath(&dirs, priv));) {
 			error = tls_config_set_key_file(config, path);
 			if (!error) break;
 		}

xdg.c

@@ -58,14 +58,14 @@ static const struct Base Data = {
 	.defDirs = "/usr/local/share:/usr/share",
 };
 
-static const char *basePath(
+static const char *
-	struct Base base,
+basePath(struct Base base, const char **dirs, const char *path) {
-	char *buf, size_t cap, const char **dirs, const char *path
+	static char buf[PATH_MAX];
-) {
+
 	if (*dirs) {
 		if (!**dirs) return NULL;
 		size_t len = strcspn(*dirs, ":");
-		snprintf(buf, cap, "%.*s/" SUBDIR "/%s", (int)len, *dirs, path);
+		snprintf(buf, sizeof(buf), "%.*s/" SUBDIR "/%s", (int)len, *dirs, path);
 		*dirs += len;
 		if (**dirs) *dirs += 1;
 		return buf;
@@ -82,29 +82,30 @@ static const char *basePath(
 	const char *home = getenv("HOME");
 	const char *baseHome = getenv(base.envHome);
 	if (baseHome) {
-		snprintf(buf, cap, "%s/" SUBDIR "/%s", baseHome, path);
+		snprintf(buf, sizeof(buf), "%s/" SUBDIR "/%s", baseHome, path);
+	} else if (home) {
+		snprintf(
+			buf, sizeof(buf), "%s/%s/" SUBDIR "/%s",
+			home, base.defHome, path
+		);
 	} else {
-		if (!home) return NULL;
+		return NULL;
-		snprintf(buf, cap, "%s/%s/" SUBDIR "/%s", home, base.defHome, path);
 	}
 	return buf;
 }
 
-const char *
+const char *configPath(const char **dirs, const char *path) {
-configPath(char *buf, size_t cap, const char **dirs, const char *path) {
+	return basePath(Config, dirs, path);
-	return basePath(Config, buf, cap, dirs, path);
 }
 
 const char *
-dataPath(char *buf, size_t cap, const char **dirs, const char *path) {
+dataPath(const char **dirs, const char *path) {
-	return basePath(Data, buf, cap, dirs, path);
+	return basePath(Data, dirs, path);
 }
 
 FILE *configOpen(const char *path, const char *mode) {
-	const char *abs;
-	char buf[PATH_MAX];
 	const char *dirs = NULL;
-	while (NULL != (abs = configPath(buf, sizeof(buf), &dirs, path))) {
+	for (const char *abs; NULL != (abs = configPath(&dirs, path));) {
 		FILE *file = fopen(abs, mode);
 		if (file) return file;
 		if (errno != ENOENT) warn("%s", abs);
@@ -115,31 +116,31 @@ FILE *configOpen(const char *path, const char *mode) {
 }
 
 void dataMkdir(const char *path) {
-	char buf[PATH_MAX];
 	const char *dirs = NULL;
-	const char *abs = dataPath(buf, sizeof(buf), &dirs, path);
+	const char *abs = dataPath(&dirs, path);
+	if (!abs) return;
 	int error = mkdir(abs, S_IRWXU);
 	if (error && errno != EEXIST) warn("%s", abs);
 }
 
 FILE *dataOpen(const char *path, const char *mode) {
-	const char *abs;
-	char buf[PATH_MAX];
 	const char *dirs = NULL;
-	while (NULL != (abs = dataPath(buf, sizeof(buf), &dirs, path))) {
+	for (const char *abs; NULL != (abs = dataPath(&dirs, path));) {
 		FILE *file = fopen(abs, mode);
 		if (file) return file;
 		if (errno != ENOENT) warn("%s", abs);
 	}
 
 	if (mode[0] != 'r') {
-		dirs = NULL;
-		abs = dataPath(buf, sizeof(buf), &dirs, path);
-		if (!abs) return NULL;
-
 		dataMkdir("");
-		FILE *file = fopen(abs, mode);
+		dirs = NULL;
-		if (!file) warn("%s", abs);
+		path = dataPath(&dirs, path);
+		if (!path) {
+			warn("HOME unset");
+			return NULL;
+		}
+		FILE *file = fopen(path, mode);
+		if (!file) warn("%s", path);
 		return file;
 	}