[alsa-devel] [PATCH] alsactl: Try to create state file directory

[Dan Nicholson]

Try to create the directory for the state file when saving so we don't
depend on it being created ahead of time. This only checks for failures
on existing directories and doesn't try to create the leading
directories or workaround any other errors. This should catch the common
case where /var/lib exists, but /var/lib/alsa doesn't.

Signed-off-by: Dan Nicholson <nicholson at endlessm.com>
---
v2: I forgot to set err if mkdir failed.

 alsactl/state.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/alsactl/state.c b/alsactl/state.c
index 3908ec4..faa1579 100644
--- a/alsactl/state.c
+++ b/alsactl/state.c
@@ -27,6 +27,9 @@
 #include <stdio.h>
 #include <assert.h>
 #include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <alsa/asoundlib.h>
 #include "alsactl.h"
 
@@ -1544,6 +1547,7 @@ int save_state(const char *file, const char *cardname)
 	snd_output_t *out;
 	int stdio;
 	char *nfile = NULL;
+	char *filedir = NULL;
 	int lock_fd = -EINVAL;
 
 	err = snd_config_top(&config);
@@ -1553,6 +1557,9 @@ int save_state(const char *file, const char *cardname)
 	}
 	stdio = !strcmp(file, "-");
 	if (!stdio) {
+		char *tmp;
+		mode_t mode = S_IRWXU | S_IRWXG | S_IRWXO;
+
 		nfile = malloc(strlen(file) + 5);
 		if (nfile == NULL) {
 			error("No enough memory...");
@@ -1561,6 +1568,22 @@ int save_state(const char *file, const char *cardname)
 		}
 		strcpy(nfile, file);
 		strcat(nfile, ".new");
+		filedir = strdup(file);
+		if (filedir == NULL) {
+			error("Not enough memory...");
+			err = -ENOMEM;
+			goto out;
+		}
+		tmp = strrchr(filedir, '/');
+		if (tmp && tmp != filedir) {
+			*tmp = '\0';
+			if (mkdir(filedir, mode) != 0 && errno != EEXIST) {
+				error("Could not create directory %s: %s",
+				      filedir, strerror(errno));
+				err = -errno;
+				goto out;
+			}
+		}
 		lock_fd = state_lock(file, 10);
 		if (lock_fd < 0) {
 			err = lock_fd;
@@ -1640,6 +1663,7 @@ out:
 	if (!stdio && lock_fd >= 0)
 		state_unlock(lock_fd, file);
 	free(nfile);
+	free(filedir);
 	snd_config_delete(config);
 	snd_config_update_free_global();
 	return err;
-- 
1.8.1.2