env: Introduce pr_setenv()

It's a common pattern to (ba)sprintf to a string and then call setenv()
with this string. Introduce pr_setenv() as a shortcut to simplify this
pattern.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 30 insertions, 2 deletions

diff --git a/common/env.c b/common/env.c
index 05add63f62..5ac1e62b8c 100644
--- a/common/env.c
+++ b/common/env.c
@@ -244,13 +244,12 @@ static int dev_setenv(const char *name, const char *val)
 
 /**
  * setenv - set environment variables
- * @_name - Variable name
+ * @name - Variable name
  * @value - the value to set, empty string not handled specially
  *
  * Returns 0 for success and a negative error code otherwise
  * Use unsetenv() to unset.
  */
-
 int setenv(const char *_name, const char *value)
 {
 	char *name = strdup(_name);
@@ -277,6 +276,35 @@ out:
 }
 EXPORT_SYMBOL(setenv);
 
+/**
+ * pr_setenv - set environment variables
+ * @name - Variable name
+ * @fmt - the format string to use
+ *
+ * Returns 0 for success and a negative error code otherwise
+ * Use unsetenv() to unset.
+ */
+int pr_setenv(const char *name, const char *fmt, ...)
+{
+	va_list ap;
+	int ret = 0;
+	char *value;
+	int len;
+
+	va_start(ap, fmt);
+	len = vasprintf(&value, fmt, ap);
+	va_end(ap);
+
+	if (len < 0)
+		return -ENOMEM;
+
+	ret = setenv(name, value);
+	free(value);
+
+	return ret;
+}
+EXPORT_SYMBOL(pr_setenv);
+
 int export(const char *varname)
 {
 	const char *val = getenv_raw(&context->local, varname);