#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
+#include <string.h>
+#include <time.h>
#include <sys/epoll.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "baud.h"
#include "debug.h"
-int read_data(int infd, int outfd)
+/**
+ * Read data from a slow device
+ *
+ * return 1 when a complete NULL terminated line has been read
+ *
+ * return 0 when a partial line has been read and appended to the
+ * buffer at @offset
+ *
+ * return negative on error
+ */
+static int read_log_line(int infd, char *buf, size_t bufsize, int *offset)
+{
+ int ret;
+ int i;
+
+ ret = read(infd, buf + *offset, bufsize - *offset - 1);
+ if (ret < 0) {
+ pr_err("read: %m\n");
+ return -1;
+ }
+
+ if (ret == 0) {
+ pr_err("Read EOF, stopping\n");
+ return -1;
+ }
+ buf[*offset + ret] = 0;
+
+ for (i = 0; i < ret; i++) {
+ if (buf[i + *offset] == '\n' ||
+ buf[i + *offset] == '\r') {
+ /*
+ * Got a complete line when there is a newline
+ * at the end. Remove the newline and possible
+ * other junk, such as '\r'
+ */
+ buf[i + *offset] = 0;
+ *offset = 0;
+
+ return 1;
+ }
+
+ /*
+ * Fixme! Nothing guarantees that there isn't actually
+ * more data (a part of a new log entry perhaps) after
+ * the newline. So in rare cases (we are prevented
+ * from reading the serial line in very long time) we
+ * might lose data from the stream..
+ */
+ }
+
+ *offset += ret;
+ return 0;
+}
+
+static int read_data(int infd, int outfd)
{
struct epoll_event ev;
+ time_t start_time = 0, cur_time;
int epoll_fd;
int ret;
char buf[256];
+ int offset;
epoll_fd = epoll_create(1);
if (epoll_fd < 0) {
}
while (1) {
+ char str[320];
+ int len;
+
ret = epoll_wait(epoll_fd, &ev, 1, -1);
if (ret == 0)
continue;
return -1;
}
- ret = read(infd, buf, sizeof(buf));
- if (read < 0) {
- pr_err("read: %m\n");
- break;
- }
+ ret = read_log_line(infd, buf, sizeof(buf), &offset);
+ if (ret < 0)
+ return ret;
- if (ret == 0) {
- pr_err("Read EOF, stopping\n");
- break;
+ if (ret == 0)
+ continue;
+
+ if (strlen(buf) < 5) {
+ pr_debug("discarding truncated log entry\n");
+ offset = 0;
+ continue;
}
- ret = write(outfd, buf, ret);
- if (read < 0) {
+ if (!start_time)
+ start_time = time(NULL);
+
+ cur_time = time(NULL);
+
+ pr_info("%s\n", buf);
+
+ if (!outfd)
+ continue;
+
+ len = snprintf(str, sizeof(str),
+ "%ld;%s\n", cur_time - start_time, buf);
+
+ ret = write(outfd, str, len);
+ if (ret < 0) {
pr_err("write: %m\n");
break;
}
int main(int argc, char *argv[])
{
struct plotter_options options;
- int fd, baud, ret = 0, out_fd = STDOUT_FILENO;
+ int fd, baud, ret = 0, out_fd = 0;
if (read_args(argc, argv, &options))
return 1;