From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Thu, 11 Feb 2021 09:14:34 +0000 (+0100)
Subject: string_utils: add wrapper for snprintf()
X-Git-Tag: lxc-5.0.0~292^2~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=66efb199f75a49c13246d760e894bd0f4891e5ce;p=thirdparty%2Flxc.git

string_utils: add wrapper for snprintf()

This let's us avoid the tedious

if (ret < 0 || (size_t)ret >= sizeof(buf))

style of error checking.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---

diff --git a/src/lxc/string_utils.h b/src/lxc/string_utils.h
index a489cac44..dd086cee7 100644
--- a/src/lxc/string_utils.h
+++ b/src/lxc/string_utils.h
@@ -140,4 +140,13 @@ static inline bool strequal(const char *str, const char *eq)
 	return strcmp(str, eq) == 0;
 }
 
+#define strnprintf(buf, buf_size, ...)                                            \
+	({                                                                        \
+		int __ret_strnprintf;                                             \
+		__ret_strnprintf = snprintf(buf, buf_size, ##__VA_ARGS__);        \
+		if (__ret_strnprintf < 0 || (size_t)__ret_strnprintf >= buf_size) \
+			__ret_strnprintf = ret_errno(EIO);                        \
+		__ret_strnprintf;                                                 \
+	})
+
 #endif /* __LXC_STRING_UTILS_H */