#include <stdio.h>
#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
#include <sys/epoll.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#include "options.h"
#include "baud.h"
#include "debug.h"
-int main(int argc, char *argv[])
+/**
+ * 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)
{
- struct epoll_event ev;
- struct plotter_options options;
- int fd, baud, ret;
- int epoll_fd;
- char buf[256];
+ int ret;
+ int i;
+ ret = read(infd, buf + *offset, bufsize - *offset - 1);
+ if (ret < 0) {
+ pr_err("read: %m\n");
+ return -1;
+ }
- if (read_args(argc, argv, &options))
- return 1;
+ if (ret == 0) {
+ pr_err("Read EOF, stopping\n");
+ return -1;
+ }
+ buf[*offset + ret] = 0;
- baud = options.baud_rate;
- fd = open_at_baud(options.device_path, &baud);
- if (fd < 0)
- return 1;
+ 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;
- if (baud != options.baud_rate) {
- pr_err("Failed to set baudrate to %d, only got %d\n",
- options.baud_rate, baud);
- close(fd);
- return 1;
+ 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;
+ int epoll_fd;
+ int ret;
+ char buf[256];
+ int offset;
+
epoll_fd = epoll_create(1);
+ if (epoll_fd < 0) {
+ pr_err("Failed to create epoll socket: %m\n");
+ return -1;
+ }
ev.events = EPOLLIN;
- ev.data.fd = fd;
- if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
+ ev.data.fd = infd;
+ if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, infd, &ev) == -1) {
pr_err("epoll_ctl: %m\n");
return 1;
}
if (ret < 0) {
pr_err("epoll: %m\n");
- return 1;
+ return -1;
}
- ret = read(fd, 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)
+ continue;
- if (ret == 0) {
- pr_err("Read EOF, stopping\n");
- break;
+ if (outfd) {
+ char newline = '\n';
+ ret = write(outfd, buf, strlen(buf));
+ if (read < 0) {
+ pr_err("write: %m\n");
+ break;
+ }
+ ret = write(outfd, &newline, 1);
+ if (read < 0) {
+ pr_err("write: %m\n");
+ break;
+ }
}
- ret = write(1, buf, ret);
- if (read < 0) {
- pr_err("write: %m\n");
- break;
+ pr_info("%s\n", buf);
+ }
+
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ struct plotter_options options;
+ int fd, baud, ret = 0, out_fd = 0;
+
+ if (read_args(argc, argv, &options))
+ return 1;
+
+ baud = options.baud_rate;
+ fd = open_at_baud(options.device_path, &baud);
+ if (fd < 0)
+ return 1;
+
+ if (baud != options.baud_rate) {
+ pr_err("Failed to set baudrate to %d, only got %d\n",
+ options.baud_rate, baud);
+ ret = 1;
+ goto out;
+ }
+
+ if (options.output_path) {
+ pr_debug("Opening %s for writing the log file\n",
+ options.output_path);
+
+ out_fd = open(options.output_path,
+ O_CREAT | O_APPEND | O_WRONLY, 0664);
+ if (out_fd < 0) {
+ pr_err("Failed to open file %s for writing: %m\n",
+ options.output_path);
+ ret = 1;
+ goto out;
}
}
+ read_data(fd, out_fd);
+
+out:
close(fd);
- return 0;
+ return ret;
}