+ Add system timestamps to lua read() and new lua read_line() per global options

+ Add missing timestamp-format epoch
+ Update send_ to use fsync and tcdrain like normal tty_sync does
+ Rework read_line to save partial line at timeout
+ Simplified read_line to reduce cyclomatic complexity

+ renamed example files read.lua and read_line.lua
+ moved #define READ_LINE_SIZE to top of file
+ renamed g_linebuf to linebuf, and moved it into read_line as a static variable

examples/lua/read.lua

@@ -0,0 +1,14 @@
+read(1000, 6000) -- initial config
+send("\n")
+msleep(100)
+read(650, 60) -- main menu
+send("S") -- S menu
+msleep(30)
+read(650, 60)
+send("t") -- Parallel Value Table
+read(650, 60)
+while true do
+  msleep(1000)
+  send("t")
+  read(650, 50) -- repeat PVT forever
+end

examples/lua/read_line.lua

@@ -0,0 +1,17 @@
+read(1000, 8000) -- read initial config
+send("\n")
+read(650, 100) -- main menu
+send("S") -- S menu
+n = 1
+while n > 0 do -- while not empty, read more
+  n, str = read_line(25)
+end
+while true do
+  send("t") -- query PV table
+  msleep(880)
+  n = 1
+  while n > 0 do -- while not empty, read more
+    n, str = read_line(60)
+    msleep(60)
+  end
+end

man/tio.1.in

@@ -467,7 +467,18 @@ until data is ready to read.
 
 Returns number of bytes read on success, 0 on timeout, or -1 on error.
 
-On success, returns read string as second return value.
+On success, returns read string as second return value.  Also emits a single
+timestamp to stdout and log file per options.timestamp and options.log.
+
+.IP "\fBread_line(timeout)"
+Read line from serial device. If timeout is 0 or not provided it will wait
+forever until data is ready to read.
+
+Returns number of bytes read on success, 0 on timeout, or -1 on error.
+
+On success, returns the string that was read as second return value.  Also
+emits a single timestamp to stdout and log file per options.timestamp
+and options.log.
 
 .IP "\fBset{line=state, ...}"
 Set state of one or multiple tty modem lines.

man/tio.1.txt

@@ -373,7 +373,14 @@ SCRIPT API
 
              Returns number of bytes read on success, 0 on timeout, or -1 on error.
 
-             On success, returns read string as second return value.
+             On success, returns read string as second return value. Also emits a single timestamp to stdout and log file per options.timestamp and options.log.
+
+       read_line(timeout)
+             Read line from serial device. If timeout is 0 or not provided it will wait forever until data is ready to read.
+
+             Returns number of bytes read on success, 0 on timeout, or -1 on error.
+
+             On success, returns the string that was read as second return value.  Also emits a single timestamp to stdout and log file per options.timestamp and options.log.
 
        set{line=state, ...}
              Set state of one or multiple tty modem lines.

src/configfile.c

@@ -209,7 +209,7 @@ static void config_parse_keys(GKeyFile *key_file, char *group)
     {
         option.timestamp = TIMESTAMP_24HOUR;
     }
-    config_get_string(key_file, group, "timestamp-format", &string, "24hour", "24hour-start", "24hour-delta", "iso8601", NULL);
+    config_get_string(key_file, group, "timestamp-format", &string, "24hour", "24hour-start", "24hour-delta", "iso8601", "epoch", NULL);
     if (string != NULL)
     {
         option_parse_timestamp(string, &option.timestamp);

src/error.c

@@ -19,8 +19,7 @@
  * 02110-1301, USA.
  */
 
-#define __STDC_WANT_LIB_EXT2__ 1   // To access vasprintf
+#define _GNU_SOURCE    // To access vasprintf
-
 #include <stdio.h>
 #include "print.h"
 

src/log.c

@@ -19,8 +19,7 @@
  * 02110-1301, USA.
  */
 
-#define __STDC_WANT_LIB_EXT2__ 1   // To access vasprintf
+#define _GNU_SOURCE // To access vasprintf
-
 #include <sys/time.h>
 #include <libgen.h>
 #include <errno.h>

src/options.c

@@ -19,6 +19,8 @@
  * 02110-1301, USA.
  */
 
+#define _GNU_SOURCE // To access vasprintf
+
 #include <assert.h>
 #include <regex.h>
 #include <getopt.h>

src/script.c

@@ -29,6 +29,7 @@
 #include <lauxlib.h>
 #include <lualib.h>
 #include <sys/ioctl.h>
+#include <ctype.h>
 #include "misc.h"
 #include "print.h"
 #include "options.h"
@@ -37,8 +38,11 @@
 #include "log.h"
 #include "script.h"
 #include "fs.h"
+#include "timestamp.h"
+#include "termios.h"
 
 #define MAX_BUFFER_SIZE 2000 // Maximum size of circular buffer
+#define READ_LINE_SIZE 4096 // read_line buffer length
 
 static int device_fd;
 static char circular_buffer[MAX_BUFFER_SIZE];
@@ -192,6 +196,8 @@ static int send_(lua_State *L)
     }
 
     ret = write(device_fd, string, strlen(string));
+    fsync(device_fd);  // flush these characters now
+    tcdrain(device_fd); //ensure we flushed characters to our device
 
     lua_pushnumber(L, ret);
 
@@ -248,18 +254,47 @@ static bool match_regex(regex_t *regex)
     return false;
 }
 
-// lua: ret,string = read_string(size, timeout)
+// Function to echo a buffer to stdout and to the log
+// per the option.timestamp and option.log settings
+static void echo_buffer(char buffer[], ssize_t len)
+{
+    if (option.timestamp)
+    {
+        char *pTimeStampNow;
+        pTimeStampNow = timestamp_current_time();
+        if (pTimeStampNow)
+        {
+            tio_printf("%s", buffer); //does timestamps for us
+            if (option.log)
+            {
+                log_printf("\n[%s] %s", pTimeStampNow, buffer);
+            }
+        }
+    } else {
+        for (ssize_t i=0; i<len; i++)
+        {
+            putchar(buffer[i]);
+
+            if (option.log)
+            {
+                log_putc(buffer[i]);
+            }
+        }
+    }
+}
+
+// lua: ret,string = read(size, timeout)
 static int read_string(lua_State *L)
 {
-    int size = lua_tointeger(L, 1);
+    int size = lua_tointeger(L, 1) + 1; //plus one for null-terminated string
     int timeout = lua_tointeger(L, 2);
     int ret = 0;
 
-    char *buffer = malloc(size);
+    char *buffer = calloc(1, size);
     if (buffer == NULL)
     {
         ret = -1; // Error
-        goto error;
+        goto error_rs;
     }
 
     if (timeout == 0)
@@ -271,33 +306,94 @@ static int read_string(lua_State *L)
     if (bytes_read < 0)
     {
         ret = -1; // Error
-        goto error;
+        goto error_rs;
     }
     else if (bytes_read == 0)
     {
         ret = 0; // Timeout
-        goto error;
+        goto error_rs;
     }
-
+    else
-    for (ssize_t i=0; i<bytes_read; i++)
     {
-        putchar(buffer[i]);
+        buffer[bytes_read] = (char)0;
-
-        if (option.log)
-        {
-            log_putc(buffer[i]);
-        }
     }
 
+    echo_buffer(&buffer[0], bytes_read);
     ret = bytes_read;
 
-error:
+error_rs:
     lua_pushnumber(L, ret);
     if (buffer != NULL)
     {
-        lua_pushstring(L, buffer);
+        lua_pushstring(L, ret > 0 ? buffer : "");
         free(buffer);
     }
+    else
+    {
+        lua_pushstring(L, ""); // give empty string to caller
+    }
+    return 2;
+}
+
+// lua: ret,string = read_line(timeout)
+static int read_line(lua_State *L)
+{
+    static char linebuf[READ_LINE_SIZE];
+    int timeout = lua_tointeger(L, 1); //ms
+    int ret = 0;
+    int read_result = 1; //enable reading input from device
+    char ch;
+    int bytes_read = 0;
+
+    linebuf[0] = '\0';
+    if (timeout == 0)
+    {
+        timeout = -1; // Wait forever
+    }
+
+    // loop reading input until a newline seen or timeout
+    while (true)
+    {
+        read_result = read_poll(device_fd, &ch, 1, timeout);
+        if (read_result < 0)
+        {
+            ret = -1; // Error
+            linebuf[bytes_read] = '\0';
+            goto error_rl;
+        }
+        else if (!read_result)
+        {
+            // Timeout returns a non-empty linebuf as a 'line'
+            ret = bytes_read;
+            linebuf[bytes_read] = '\0';
+            break;
+        }
+        else // we got a character, so handle it
+        {
+            if (ch == '\n')
+            {
+                linebuf[bytes_read] = '\0';
+                break;
+            }
+            else if (bytes_read <= (READ_LINE_SIZE-2))
+            {
+                if (isprint(ch)) // store all printable chars
+                {
+                    linebuf[bytes_read++] = ch;
+                }
+            }
+        }
+    }
+
+    if (bytes_read)
+    {
+        echo_buffer(linebuf, bytes_read);
+    }
+    ret = bytes_read;
+
+error_rl:
+    lua_pushnumber(L, ret);
+    lua_pushstring(L, linebuf);
     return 2;
 }
 
@@ -457,6 +553,7 @@ static const struct luaL_Reg tio_lib[] =
     { "modem_send", modem_send},
     { "send", send_},
     { "read", read_string},
+    { "read_line", read_line},
     { "expect", expect},
     { "exit", exit_},
     { "tty_search", tty_search_},

src/timestamp.c

@@ -29,8 +29,6 @@
 #include "options.h"
 #include "timestamp.h"
 
-#define TIME_STRING_SIZE_MAX 24
-
 char *timestamp_current_time(void)
 {
     static char time_string[TIME_STRING_SIZE_MAX];

src/timestamp.h

@@ -32,5 +32,7 @@ typedef enum
     TIMESTAMP_END,
 } timestamp_t;
 
+#define TIME_STRING_SIZE_MAX 24
+
 char *timestamp_current_time(void);
 

src/tty.c

@@ -1615,6 +1615,7 @@ const char* get_serial_port_type(const char* port_name)
 
 const char* get_serial_port_type(const char* port_name)
 {
+    (void)port_name;
     return "";
 }