Hi, int sysfs_write_attribute(struct sysfs_attribute *sysattr, const char *new_value, size_t len) has a problematic "feature": if the file is empty but readable, nothing gets written into it. The attached patch (untested) should fix it. Dominik The check which tests whether the value to be written into a sysfs attribute is already there should only trigger if the length of both strings is the same. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> --- sysfsutils-1.2.0/lib/sysfs_dir.c.original 2005-02-21 08:10:33.000000000 +0100 +++ sysfsutils-1.2.0/lib/sysfs_dir.c 2005-02-21 08:14:01.000000000 +0100 @@ -194,7 +194,8 @@ dprintf("Error reading attribute\n"); return -1; } - if ((strncmp(sysattr->value, new_value, sysattr->len)) == 0) { + if (((strncmp(sysattr->value, new_value, sysattr->len)) == 0)&& + (len == sysattr->len)) { dprintf("Attr %s already has the requested value %s\n", sysattr->name, new_value); return 0;