string_utils: add fdstr()

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

diff --git a/src/lxc/string_utils.h b/src/lxc/string_utils.h
index c98429c092a3a24995be0db065ba5a2569857a06..f12879254742752405af2ebbd8ceeecb1a082200 100644 (file)
--- a/src/lxc/string_utils.h
+++ b/src/lxc/string_utils.h
@@ -161,4 +161,15 @@ static inline const char *proc_self_fd(int fd)
        return buf;
 }
 
+static inline const char *fdstr(int fd)
+{
+       static const char *fdstr_invalid = "-EBADF";
+       static char buf[INTTYPE_TO_STRLEN(int)];
+
+       if (strnprintf(buf, sizeof(buf), "%d", fd) < 0)
+               return fdstr_invalid;
+
+       return buf;
+}
+
 #endif /* __LXC_STRING_UTILS_H */