Refactor code logic according to suggestions for PR linux-can#521

Author: GGZ8

canplayer.c

@@ -48,6 +48,7 @@
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <stdbool.h>
 
 #include <linux/can.h>
 #include <linux/can/raw.h>
@@ -89,11 +90,11 @@ const int canfx_on = 1;
 
 extern int optind, opterr, optopt;
 
-typedef struct {
+struct sleep {
 	struct timeval *sleep_vector;
 	size_t idx;
 	size_t size;
-} sleep_struct;
+};
 
 static void print_usage(char *prg)
 {
@@ -260,28 +261,36 @@ static int add_assignment(char *mode, int socket, char *txname,
 	return 0;
 }
 
-void load_gaps_from_file(FILE *fp, sleep_struct *a)
+void load_gaps_from_file(FILE *fp, struct sleep *timestamps)
 {
 	char *line = NULL;
 	size_t len = 0;
 	ssize_t read;
 
 	while ((read = getline(&line, &len, fp)) != -1) {
-		if (a->idx == a->size) {
-			a->size++;
-			a->sleep_vector = realloc(a->sleep_vector, a->size * sizeof(struct timespec));
+		if (timestamps->idx == timestamps->size) {
+			timestamps->size++;
+			timestamps->sleep_vector = realloc(timestamps->sleep_vector, timestamps->size * sizeof(struct timeval));
+			if (!timestamps->sleep_vector) {
+				fprintf(stderr, "Failed to create the timestamps vector!\n");
+				exit(1);
+			}
 		}
-		sscanf(line, "(%lu.%lu)", &a->sleep_vector[a->idx].tv_sec, &a->sleep_vector[a->idx].tv_usec);
-		a->idx++;
+		sscanf(line, "(%lu.%lu)", &timestamps->sleep_vector[timestamps->idx].tv_sec, &timestamps->sleep_vector[timestamps->idx].tv_usec);
+		timestamps->idx++;
 	}
 	free(line);
 }
 
-void init_sleep_struct(sleep_struct *a, size_t init_size)
+void init_timestamps(struct sleep *timestamps, size_t init_size)
 {
-	a->size = init_size;
-	a->sleep_vector = malloc(init_size * sizeof(struct timespec));
-	a->idx = 0;
+	timestamps->size = init_size;
+	timestamps->sleep_vector = calloc(init_size, sizeof(*(timestamps->sleep_vector)));
+	if (!timestamps->sleep_vector) {
+		fprintf(stderr, "Failed to create the timestamps vector!\n");
+		exit(1);
+	}
+	timestamps->idx = 0;
 }
 
 int main(int argc, char **argv)
@@ -310,8 +319,8 @@ int main(int argc, char **argv)
 	int eof, txmtu, i, j;
 	char *fret;
 	unsigned long long sec, usec;
-	int gap_from_file = 0;
-	sleep_struct time_arr;
+	bool gap_from_file = false;
+	struct sleep timestamps;
 	struct timeval send_time, act_time, init_time;
 
 	while ((opt = getopt(argc, argv, "I:l:tin:g:s:xvr?")) != -1) {
@@ -370,14 +379,14 @@ int main(int argc, char **argv)
 			break;
 
 		case 'r':
-			if (infile == stdin) {
+			if (!isatty(fileno(infile))) {
 				fprintf(stderr, "Specify an input file for option -r !\n");
 				exit(EXIT_FAILURE);
 			}
-			gap_from_file = 1; /* using time delta from file */
-			init_sleep_struct(&time_arr, 1);
-			load_gaps_from_file(infile, &time_arr);
-			time_arr.idx = 0;
+			gap_from_file = true; /* using time delta from file */
+			init_timestamps(&timestamps, 1);
+			load_gaps_from_file(infile, &timestamps);
+			timestamps.idx = 0;
 			break;
 
 		case '?':
@@ -555,8 +564,8 @@ int main(int argc, char **argv)
 					addr.can_family = AF_CAN;
 					addr.can_ifindex = txidx; /* send via this interface */
 
-					if (gap_from_file && time_arr.idx > 0) {
-						send_time = time_arr.sleep_vector[time_arr.idx];
+					if (gap_from_file && timestamps.idx > 0) {
+						send_time = timestamps.sleep_vector[timestamps.idx];
 						gettimeofday(&act_time, NULL);
 						timersub(&act_time, &init_time, &act_time);
 
@@ -565,12 +574,12 @@ int main(int argc, char **argv)
 							timersub(&act_time, &init_time, &act_time);
 						}
 					}
-					if (gap_from_file && time_arr.idx == 0) {
+					if (gap_from_file && timestamps.idx == 0) {
 						gettimeofday(&init_time, NULL);
 						gettimeofday(&act_time, NULL);
 						timersub(&act_time, &init_time, &act_time);
 					}
-					time_arr.idx++;
+					timestamps.idx++;
 
 					if (sendto(s, &cu, txmtu, 0, (struct sockaddr *)&addr, sizeof(addr)) != txmtu) {
 						perror("sendto");