Track line number for error reports

jsoncat.c

@@ -88,7 +88,7 @@ void process(FILE *f) {
 	}
 
 	if (jp->error != NULL) {
-		fprintf(stderr, "%s\n", jp->error);
+		fprintf(stderr, "%d: %s\n", jp->line, jp->error);
 	}
 }
 

jsonpull.c

@@ -9,19 +9,24 @@ typedef enum json_expect {
 	JSON_ITEM, JSON_COMMA, JSON_COLON, JSON_KEY, JSON_VALUE,
 } json_expect;
 
-static int read_file(json_pull *p) {
-	return fgetc(p->source);
+static int read_file(json_pull *j) {
+	int c = fgetc(j->source);
+	if (c == '\n') {
+		j->line++;
+	}
+	return c;
 }
 
-static int peek_file(json_pull *p) {
-	int c = getc(p->source);
-	ungetc(c, p->source);
+static int peek_file(json_pull *j) {
+	int c = getc(j->source);
+	ungetc(c, j->source);
 	return c;
 }
 
 json_pull *json_begin_file(FILE *f) {
 	json_pull *j = malloc(sizeof(json_pull));
 	j->container = NULL;
+	j->line = 1;
 
 	j->read = read_file;
 	j->peek = peek_file;
@@ -30,14 +35,17 @@ json_pull *json_begin_file(FILE *f) {
 	return j;
 }
 
-static int read_string(json_pull *p) {
-	char *cp = p->source;
+static int read_string(json_pull *j) {
+	char *cp = j->source;
 	if (*cp == '\0') {
 		return EOF;
 	}
 	int c = (unsigned char) *cp;
 	cp++;
-	p->source = cp;
+	j->source = cp;
+	if (c == '\n') {
+		j->line++;
+	}
 	return c;
 }
 
@@ -52,6 +60,7 @@ static int peek_string(json_pull *p) {
 json_pull *json_begin_string(char *s) {
 	json_pull *j = malloc(sizeof(json_pull));
 	j->container = NULL;
+	j->line = 1;
 
 	j->read = read_string;
 	j->peek = peek_string;

jsonpull.h

@@ -24,6 +24,7 @@ struct json_pull {
 	int (*read)(struct json_pull *);
 	int (*peek)(struct json_pull *);
 	void *source;
+	int line;
 };
 typedef struct json_pull json_pull;