Make the %V{is} extension handle a NULL pointer like %s does: output "(null)"

Add %M{essage} extension which prints an errno value as the
corresponding string if possible or numerically otherwise.

It is not currently possible to do the syslog(3) like %m extension
because errno would need to get capatured on entry to the first
function in the printf family, so %M requires you to supply errno
as an argument.

Add %Q{uote} extension which will print a string in double quotes with
appropriate back-slash escapes (only) if necessary.

1 files changed, 65 insertions, 0 deletions

diff --git a/lib/libc/stdio/xprintf_errno.c b/lib/libc/stdio/xprintf_errno.c
new file mode 100644
index 0000000..0c2be46
--- /dev/null
+++ b/lib/libc/stdio/xprintf_errno.c
@@ -0,0 +1,65 @@
+/*-
+ * Copyright (c) 2005 Poul-Henning Kamp
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <namespace.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <wchar.h>
+#include <vis.h>
+#include <assert.h>
+#include <sys/time.h>
+#include "printf.h"
+
+int
+__printf_arginfo_errno(const struct printf_info *pi __unused, size_t n, int *argt)
+{
+
+	assert(n >= 1);
+	argt[0] = PA_INT;
+	return (1);
+}
+
+int
+__printf_render_errno(struct __printf_io *io, const struct printf_info *pi __unused, const void *const *arg)
+{
+	int ret, error;
+	char buf[64];
+	const char *p;
+
+	ret = 0;
+	error = *((const int *)arg[0]);
+	if (error >= 0 && error < sys_nerr) {
+		p = strerror(error);
+		return (__printf_out(io, pi, p, strlen(p)));
+	}
+	sprintf(buf, "errno=%d/0x%x", error, error);
+	ret += __printf_out(io, pi, buf, strlen(buf));
+	__printf_flush(io);
+	return(ret);
+}