From ea2bc257623833311965a798611f2dc114a569e8 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Fri, 11 Sep 2020 17:41:10 +0900
Subject: [PATCH] sd-device: introduce sd_device_set_sysattr_valuef()

---
 src/libsystemd/libsystemd.sym        |  1 +
 src/libsystemd/sd-device/sd-device.c | 23 +++++++++++++++++++++++
 src/systemd/sd-device.h              |  1 +
 3 files changed, 25 insertions(+)

diff --git a/src/libsystemd/libsystemd.sym b/src/libsystemd/libsystemd.sym
index 1bee5318d6..c6dfcd6791 100644
--- a/src/libsystemd/libsystemd.sym
+++ b/src/libsystemd/libsystemd.sym
@@ -732,4 +732,5 @@ global:
         sd_device_get_current_tag_first;
         sd_device_get_current_tag_next;
         sd_device_has_current_tag;
+        sd_device_set_sysattr_valuef;
 } LIBSYSTEMD_246;
diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index bf92fda6d9..634c9a24f8 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -1979,3 +1979,26 @@ _public_ int sd_device_set_sysattr_value(sd_device *device, const char *sysattr,
 
         return 0;
 }
+
+_public_ int sd_device_set_sysattr_valuef(sd_device *device, const char *sysattr, const char *format, ...) {
+        _cleanup_free_ char *value = NULL;
+        va_list ap;
+        int r;
+
+        assert_return(device, -EINVAL);
+        assert_return(sysattr, -EINVAL);
+
+        if (!format) {
+                device_remove_sysattr_value(device, sysattr);
+                return 0;
+        }
+
+        va_start(ap, format);
+        r = vasprintf(&value, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return sd_device_set_sysattr_value(device, sysattr, value);
+}
diff --git a/src/systemd/sd-device.h b/src/systemd/sd-device.h
index d720ce50da..53092d28f9 100644
--- a/src/systemd/sd-device.h
+++ b/src/systemd/sd-device.h
@@ -79,6 +79,7 @@ int sd_device_get_property_value(sd_device *device, const char *key, const char
 int sd_device_get_sysattr_value(sd_device *device, const char *sysattr, const char **_value);
 
 int sd_device_set_sysattr_value(sd_device *device, const char *sysattr, const char *value);
+int sd_device_set_sysattr_valuef(sd_device *device, const char *sysattr, const char *format, ...) _sd_printf_(3, 4);
 
 /* device enumerator */