setvbuf: return failure if mode is invalid

Submitted by A. Wilcox on March 12, 2019, 8:31 p.m.

Details

Message ID 20190312203122.64157-1-AWilcox@Wilcox-Tech.com
State New
Series "setvbuf: return failure if mode is invalid"
Headers show

Commit Message

A. Wilcox March 12, 2019, 8:31 p.m.
POSIX requires setvbuf to return non-zero if `mode` is not one of _IONBF,
_IOLBF, or _IOFBF.
---
 src/stdio/setvbuf.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

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diff --git a/src/stdio/setvbuf.c b/src/stdio/setvbuf.c
index 06ea296c..523dddc8 100644
--- a/src/stdio/setvbuf.c
+++ b/src/stdio/setvbuf.c
@@ -12,13 +12,15 @@  int setvbuf(FILE *restrict f, char *restrict buf, int type, size_t size)
 
 	if (type == _IONBF) {
 		f->buf_size = 0;
-	} else {
+	} else if (type == _IOLBF || type == _IOFBF) {
 		if (buf && size >= UNGET) {
 			f->buf = (void *)(buf + UNGET);
 			f->buf_size = size - UNGET;
 		}
 		if (type == _IOLBF && f->buf_size)
 			f->lbf = '\n';
+	} else {
+		return -1;
 	}
 
 	f->flags |= F_SVB;

Comments

Rich Felker March 13, 2019, 12:32 a.m.
On Tue, Mar 12, 2019 at 03:31:22PM -0500, A. Wilcox wrote:
> POSIX requires setvbuf to return non-zero if `mode` is not one of _IONBF,
> _IOLBF, or _IOFBF.
> ---
>  src/stdio/setvbuf.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/src/stdio/setvbuf.c b/src/stdio/setvbuf.c
> index 06ea296c..523dddc8 100644
> --- a/src/stdio/setvbuf.c
> +++ b/src/stdio/setvbuf.c
> @@ -12,13 +12,15 @@ int setvbuf(FILE *restrict f, char *restrict buf, int type, size_t size)
>  
>  	if (type == _IONBF) {
>  		f->buf_size = 0;
> -	} else {
> +	} else if (type == _IOLBF || type == _IOFBF) {
>  		if (buf && size >= UNGET) {
>  			f->buf = (void *)(buf + UNGET);
>  			f->buf_size = size - UNGET;
>  		}
>  		if (type == _IOLBF && f->buf_size)
>  			f->lbf = '\n';
> +	} else {
> +		return -1;
>  	}
>  
>  	f->flags |= F_SVB;
> -- 
> 2.19.2

Thanks; will commit. FWIW this seems to be a C requirement not
specific to POSIX.

Rich