shithub: libtags

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readtags example: add -i option to dump an image; use stderr more

--- a/examples/readtags.c

+++ b/examples/readtags.c

@@ -1,10 +1,13 @@

-#include <fcntl.h>

 #include <stdio.h>

-#include <sys/types.h>

+#include <stdbool.h>

+#include <stdlib.h>

+#include <string.h>

+#include <fcntl.h>

 #include <unistd.h>

-#define USED(x) (void)x

 #include "tags.h"

+#define USED(x) (void)x

+

 typedef struct Aux Aux;

 struct Aux {

@@ -28,10 +31,25 @@

 	[Ttrackpeak] = "trackpeak",

 };

+static bool image;

+

 static void

 tag(Tagctx *ctx, int t, const char *k, const char *v, int offset, int size, Tagread f)

 {

-	USED(ctx); USED(k); USED(f);

+	USED(k); USED(f);

+	if(image){

+		if(t != Timage)

+			return;

+		char *raw = malloc(size);

+		Aux *aux = ctx->aux;

+		if(read(aux->fd, raw, size) != size || (f != NULL && f(raw, &size) != 0)){

+			fprintf(stderr, "failed to read the image\n");

+			exit(1);

+		}

+		write(1, raw, size);

+		exit(0);

+		return;

+	}

 	if(t == Timage)

 		printf("%-12s %s %d %d\n", t2s[t], v, offset, size);

 	else if(t == Tunknown)

@@ -64,7 +82,7 @@

 main(int argc, char **argv)

 {

 	int i;

-	char buf[256];

+	char buf[256], *argv0;

 	Aux aux;

 	Tagctx ctx = {

 		.read = ctxread,

@@ -76,8 +94,15 @@

 		.aux = &aux,

 	};

+	argv0 = argv[0];

+	if(argc > 1 && strcmp(argv[1], "-i") == 0){

+		image = true;

+		argc--;

+		argv++;

+	}

+

 	if(argc < 2){

-		printf("usage: readtags FILE...\n");

+		fprintf(stderr, "usage: %s [-i] FILE...\n", argv0);

 		return 1;

 	}

@@ -86,9 +111,13 @@

 		if((aux.fd = open(argv[i], O_RDONLY)) < 0)

 			perror("failed to open");

 		else{

-			if(tagsget(&ctx) != 0)

-				printf("no tags or failed to read tags\n");

-			else{

+			if(tagsget(&ctx) != 0){

+				fprintf(stderr, "no tags or failed to read tags\n");

+				return 1;

+			}else if(image){

+				fprintf(stderr, "no images found\n");

+				return 1;

+			}else{

 				if(ctx.duration > 0)

 					printf("%-12s %d ms\n", "duration", ctx.duration);

 				if(ctx.samplerate > 0)

@@ -100,7 +129,8 @@

 			}

 			close(aux.fd);

 		}

-		printf("\n");

+		if(i+1 < argc)

+			printf("\n");

 	}

 	return 0;