[PATCH] Enhance wayland-scanner so it can use files for input and output.

[Pekka Paalanen]

On Thu, 26 Feb 2015 11:48:38 +0200
Jussi Pakkanen <jpakkane at gmail.com> wrote:

>     * Enhance wayland-scanner so it can use files for input and output
>       to improve flexibility and testability.
> 
>     Signed-off-by: Jussi Pakkanen <jpakkane at gmail.com>
> 
> ---
>  src/scanner.c | 34 +++++++++++++++++++++++++++++-----
>  1 file changed, 29 insertions(+), 5 deletions(-)
> 
> diff --git a/src/scanner.c b/src/scanner.c
> index 1f1e59a..efaf3ad 100644
> --- a/src/scanner.c
> +++ b/src/scanner.c
> @@ -28,6 +28,8 @@
>  #include <errno.h>
>  #include <ctype.h>
>  #include <expat.h>
> +#include <unistd.h>
> +#include <fcntl.h>
>  
>  #include "wayland-util.h"
>  
> @@ -39,11 +41,12 @@ enum side {
>  static int
>  usage(int ret)
>  {
> -	fprintf(stderr, "usage: ./scanner [client-header|server-header|code]\n");
> +	fprintf(stderr, "usage: ./scanner [client-header|server-header|code]"
> +		" [input_file output_file]\n");
>  	fprintf(stderr, "\n");
>  	fprintf(stderr, "Converts XML protocol descriptions supplied on "
> -			"stdin to client headers,\n"
> -			"server headers, or protocol marshalling code.\n");
> +			"stdin or input file to client\n"
> +			"headers, server headers, or protocol marshalling code.\n");
>  	exit(ret);
>  }
>  
> @@ -1252,6 +1255,7 @@ int main(int argc, char *argv[])
>  {
>  	struct parse_context ctx;
>  	struct protocol protocol;
> +	FILE *input = stdin;
>  	int len;
>  	void *buf;
>  	enum {
> @@ -1260,7 +1264,7 @@ int main(int argc, char *argv[])
>  		CODE,
>  	} mode;
>  
> -	if (argc != 2)
> +	if (argc != 2 && argc != 4)
>  		usage(EXIT_FAILURE);
>  	else if (strcmp(argv[1], "help") == 0 || strcmp(argv[1], "--help") == 0)
>  		usage(EXIT_SUCCESS);
> @@ -1273,6 +1277,26 @@ int main(int argc, char *argv[])
>  	else
>  		usage(EXIT_FAILURE);
>  
> +	if(argc == 4) {
> +		int outfd;
> +		input = fopen(argv[2], "r");
> +		if(input == NULL) {
> +			fprintf(stderr, "Could not open input file: %s\n",
> +				strerror(errno));
> +			exit(EXIT_FAILURE);
> +		}
> +		outfd = open(argv[3], O_WRONLY | O_CREAT | O_TRUNC,
> +			S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP |
> +			S_IROTH);
> +		if(outfd == -1) {
> +			fprintf(stderr, "Could not open output file: %s\n",
> +				strerror(errno));
> +			exit(EXIT_FAILURE);
> +		}
> +		dup2(outfd, STDOUT_FILENO);
> +		close(outfd);

Hi,

in addition to the other review commments, I believe the
standard way for changing the file association for stdout is to use
freopen(). Is there a reason why you didn't use freopen()?

From the freopen manual: "The  primary  use of the freopen() function
is to change the file associated with a standard text stream (stderr,
stdin, or stdout)."


Thanks,
pq

> +	}
> +
>  	wl_list_init(&protocol.interface_list);
>  	protocol.type_index = 0;
>  	protocol.null_run_length = 0;
> @@ -1293,7 +1317,7 @@ int main(int argc, char *argv[])
>  
>  	do {
>  		buf = XML_GetBuffer(ctx.parser, XML_BUFFER_SIZE);
> -		len = fread(buf, 1, XML_BUFFER_SIZE, stdin);
> +		len = fread(buf, 1, XML_BUFFER_SIZE, input);
>  		if (len < 0) {
>  			fprintf(stderr, "fread: %m\n");
>  			exit(EXIT_FAILURE);