sd-device: also add device_get_sysattr_streq()

src/libsystemd/sd-device/device-private.h

@@ -16,6 +16,7 @@ int device_get_property_bool(sd_device *device, const char *key);
 int device_get_property_int(sd_device *device, const char *key, int *ret);
 int device_get_property_uint(sd_device *device, const char *key, unsigned *ret);
 int device_get_ifname(sd_device *device, const char **ret);
+int device_get_sysattr_streq(sd_device *device, const char *sysattr, const char *expected);
 int device_get_sysattr_safe_string(sd_device *device, const char *sysattr, const char **ret);
 int device_get_sysattr_int(sd_device *device, const char *sysattr, int *ret);
 int device_get_sysattr_unsigned_full(sd_device *device, const char *sysattr, unsigned base, unsigned *ret);

src/libsystemd/sd-device/sd-device.c

@@ -2619,6 +2619,19 @@ _public_ int sd_device_get_sysattr_value(sd_device *device, const char *sysattr,
         return sd_device_get_sysattr_value_with_size(device, sysattr, ret, NULL);
 }
 
+int device_get_sysattr_streq(sd_device *device, const char *sysattr, const char *expected) {
+        const char *value;
+        int r;
+
+        assert(expected);
+
+        r = sd_device_get_sysattr_value(device, sysattr, &value);
+        if (r < 0)
+                return r;
+
+        return streq(value, expected);
+}
+
 int device_get_sysattr_safe_string(sd_device *device, const char *sysattr, const char **ret) {
         const char *value;
         int r;

src/libsystemd/sd-device/test-sd-device.c

@@ -341,6 +341,11 @@ static void test_sd_device_one(sd_device *d) {
                         ASSERT_OK_POSITIVE(device_get_sysattr_u8(d, "ifindex", &u8));
                         ASSERT_EQ(u8, (uint8_t) ifindex);
                 }
+
+                const char *s;
+                ASSERT_OK(sd_device_get_sysattr_value(d, "ifindex", &s));
+                ASSERT_OK_POSITIVE(device_get_sysattr_streq(d, "ifindex", s));
+                ASSERT_OK_ZERO(device_get_sysattr_streq(d, "ifindex", "hoge"));
         }
 }