X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=string.c;h=aa3bcbddabe425cc823e3ad5e567f707f70dbccb;hp=8c8c50ac6ef30e51ec86751837e44e0e2a4ef95f;hb=b55f405f8005821ffa369b929bc0b419da62683d;hpb=1cefe6a503c74d609db4e99e689d46575a5e40fd

diff --git a/string.c b/string.c
index 8c8c50ac..aa3bcbdd 100644
--- a/string.c
+++ b/string.c
@@ -114,6 +114,65 @@ __must_check __malloc char *para_strdup(const char *s)
 	exit(EXIT_FAILURE);
 }
 
+/**
+ * Print a formated message to a dynamically allocated string.
+ *
+ * \param result The formated string is returned here.
+ * \param fmt The format string.
+ * \param ap Initialized list of arguments.
+ *
+ * This function is similar to vasprintf(), a GNU extension which is not in C
+ * or POSIX. It allocates a string large enough to hold the output including
+ * the terminating null byte. The allocated string is returned via the first
+ * argument and must be freed by the caller. However, unlike vasprintf(), this
+ * function calls exit() if insufficient memory is available, while vasprintf()
+ * returns -1 in this case.
+ *
+ * \return Number of bytes written, not including the terminating \p NULL
+ * character.
+ *
+ * \sa printf(3), vsnprintf(3), va_start(3), vasprintf(3), \ref xasprintf().
+ */
+__printf_2_0 unsigned xvasprintf(char **result, const char *fmt, va_list ap)
+{
+	int ret;
+	size_t size;
+	va_list aq;
+
+	va_copy(aq, ap);
+	ret = vsnprintf(NULL, 0, fmt, aq);
+	va_end(aq);
+	assert(ret >= 0);
+	size = ret + 1;
+	*result = para_malloc(size);
+	va_copy(aq, ap);
+	ret = vsnprintf(*result, size, fmt, aq);
+	va_end(aq);
+	assert(ret >= 0 && ret < size);
+	return ret;
+}
+
+/**
+ * Print to a dynamically allocated string, variable number of arguments.
+ *
+ * \param result See \ref xvasprintf().
+ * \param fmt Usual format string.
+ *
+ * \return The return value of the underlying call to \ref xvasprintf().
+ *
+ * \sa \ref xvasprintf() and the references mentioned there.
+ */
+__printf_2_3 unsigned xasprintf(char **result, const char *fmt, ...)
+{
+	va_list ap;
+	unsigned ret;
+
+	va_start(ap, fmt);
+	ret = xvasprintf(result, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
 /**
  * Allocate a sufficiently large string and print into it.
  *
@@ -125,13 +184,16 @@ __must_check __malloc char *para_strdup(const char *s)
  * \return This function either returns a pointer to a string that must be
  * freed by the caller or aborts without returning.
  *
- * \sa printf(3).
+ * \sa printf(3), xasprintf().
  */
 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
 {
 	char *msg;
+	va_list ap;
 
-	PARA_VSPRINTF(fmt, msg);
+	va_start(ap, fmt);
+	xvasprintf(&msg, fmt, ap);
+	va_end(ap);
 	return msg;
 }