From: Elias Fleckenstein <eliasfleckenstein@web.de>
Date: Thu, 30 Sep 2021 14:15:44 +0000 (+0200)
Subject: Add code
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=a6c5dd9faf12ac38b1868c7ad742947a7dbeb905;p=asprintf.git

Add code
---

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..763e1a6
--- /dev/null
+++ b/README.md
@@ -0,0 +1,9 @@
+# Dragonport
+
+Dragonport is a small C library to provide portable implementations of some GNU or Linux only methods that [dragonblocks_alpha](https://github.com/dragonblocks/dragonblocks_alpha) depends on.
+It also includes methods that are technically in the POSIX standard, but are not implemented on some target platforms (or the target platforms only conform with an older standard, like Plan 9 APE).
+Where possible, dragonblocks will use an already existing library, this library is just a collection of code that is part of a bigger project that dragonblocks should not depend on or that is not compatible with dragonblocks without modifications.
+This library is only capable of what dragonblocks needs, and it does not intend to be general purpose.
+
+## Implementations
+* `asprintf.c`: Taken from [libressl-portable](https://github.com/libressl-portable/portable/blob/master/crypto/compat/bsd-asprintf.c).
diff --git a/asprintf.c b/asprintf.c
new file mode 100644
index 0000000..98a84e9
--- /dev/null
+++ b/asprintf.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2021 Elias Fleckenstein <eliasfleckenstein@web.de>
+ *
+ * Based on libressl-portable:
+ * Copyright (c) 2004 Darren Tucker.
+ *
+ * Based originally on asprintf.c from OpenBSD:
+ * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <errno.h>
+#include <limits.h> /* for INT_MAX */
+#include <stdarg.h>
+#include <stdio.h> /* for vsnprintf */
+#include <stdlib.h>
+
+#define INIT_SZ	128
+
+int
+vasprintf(char **str, const char *fmt, va_list ap)
+{
+	int ret;
+	va_list ap2;
+	char *string, *newstr;
+	size_t len;
+
+	if ((string = malloc(INIT_SZ)) == NULL)
+		goto fail;
+
+	va_copy(ap2, ap);
+	ret = vsnprintf(string, INIT_SZ, fmt, ap2);
+	va_end(ap2);
+	if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
+		*str = string;
+	} else if (ret == INT_MAX || ret < 0) { /* Bad length */
+		free(string);
+		goto fail;
+	} else {	/* bigger than initial, realloc allowing for nul */
+		len = (size_t)ret + 1;
+		if ((newstr = realloc(string, len)) == NULL) {
+			free(string);
+			goto fail;
+		}
+		va_copy(ap2, ap);
+		ret = vsnprintf(newstr, len, fmt, ap2);
+		va_end(ap2);
+		if (ret < 0 || (size_t)ret >= len) { /* failed with realloc'ed string */
+			free(newstr);
+			goto fail;
+		}
+		*str = newstr;
+	}
+	return (ret);
+
+fail:
+	*str = NULL;
+	errno = ENOMEM;
+	return (-1);
+}
+
+int asprintf(char **str, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	*str = NULL;
+	va_start(ap, fmt);
+	ret = vasprintf(str, fmt, ap);
+	va_end(ap);
+
+	return ret;
+}
diff --git a/asprintf.h b/asprintf.h
new file mode 100644
index 0000000..eef66c5
--- /dev/null
+++ b/asprintf.h
@@ -0,0 +1,9 @@
+#ifndef _DRAGONPORT_ASPINTF_H_
+#define _DRAGONPORT_ASPINTF_H_
+
+#include <stdarg.h>
+
+int vasprintf(char **str, const char *fmt, va_list ap);
+int asprintf(char **str, const char *fmt, ...);
+
+#endif _DRAGONPORT_ASPINTF_H_