[PATCH 1/8] tools/nolibc/stdio: make printf(%s) accept NULL

From: Willy Tarreau
Date: Mon Mar 21 2022 - 13:33:50 EST


It's often convenient to support this, especially in test programs where
a NULL may correspond to an allocation error or a non-existing value.
Let's make printf("%s") support being passed a NULL. In this case it
prints "(null)" like glibc's printf().

Signed-off-by: Willy Tarreau <w@xxxxxx>
---
tools/include/nolibc/stdio.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/include/nolibc/stdio.h b/tools/include/nolibc/stdio.h
index cb4d3ab3a565..559ebe052a75 100644
--- a/tools/include/nolibc/stdio.h
+++ b/tools/include/nolibc/stdio.h
@@ -220,6 +220,8 @@ int vfprintf(FILE *stream, const char *fmt, va_list args)
}
else if (c == 's') {
outstr = va_arg(args, char *);
+ if (!outstr)
+ outstr="(null)";
}
else if (c == '%') {
/* queue it verbatim */
--
2.35.1