Add key command to toggle log on/off

Add key command 'ctrl-t f' which will toggle log on/off.

If no log filename has been specified via the 'log-filename' option then
tio will automatically generate a new log filename every time the log
feature is toggled on. Meaning, when toggled multiple times, multiple
log files will be generated.

However, if a log filename has been specified, tio will only write and
append to that same file.

README.md

@@ -178,6 +178,7 @@ ctrl-t ? to list the available key commands.
 [20:19:12.040]  ctrl-t b       Send break
 [20:19:12.040]  ctrl-t c       Show configuration
 [20:19:12.040]  ctrl-t e       Toggle local echo mode
+[20:19:12.040]  ctrl-t f       Toggle log to file
 [20:19:12.040]  ctrl-t g       Toggle serial port line
 [20:19:12.040]  ctrl-t h       Toggle hexadecimal mode
 [20:19:12.040]  ctrl-t l       Clear screen

man/tio.1.in

@@ -289,6 +289,8 @@ Send serial break (triggers SysRq on Linux, etc.)
 Show configuration (baudrate, databits, etc.)
 .IP "\fBctrl-t e"
 Toggle local echo mode
+.IP "\fBctrl-t f"
+Toggle log to file
 .IP "\fBctrl-t g"
 Toggle serial port line
 .IP "\fBctrl-t h"

src/log.c

@@ -38,9 +38,9 @@
 #define IS_ESC_END_CHAR(c)              ((c >= 0x30) && (c <= 0x7E))
 #define IS_CTRL_CHAR(c)                 ((c >= 0x00) && (c <= 0x1F))
 
-static FILE *fp;
-static bool log_error = false;
+static FILE *fp = NULL;
 static char file_buffer[BUFSIZ];
+static const char *log_filename = NULL;
 
 static char *date_time(void)
 {
@@ -56,7 +56,7 @@ static char *date_time(void)
     return date_time_string;
 }
 
-void log_open(const char *filename)
+int log_open(const char *filename)
 {
     static char automatic_filename[400];
 
@@ -65,19 +65,22 @@ void log_open(const char *filename)
         // Generate filename if none provided ("tio_DEVICE_YYYY-MM-DDTHH:MM:SS.log")
         sprintf(automatic_filename, "tio_%s_%s.log", basename((char *)option.tty_device), date_time());
         filename = automatic_filename;
-        option.log_filename = automatic_filename;
     }
 
+    log_filename = filename;
+
     // Open log file in append write mode
     fp = fopen(filename, "a+");
     if (fp == NULL)
     {
-        log_error = true;
-        exit(EXIT_FAILURE);
+        tio_warning_printf("Could not open log file %s (%s)", filename, strerror(errno));
+        return -1;
     }
 
     // Enable line buffering
     setvbuf(fp, file_buffer, _IOLBF, BUFSIZ);
+
+    return 0;
 }
 
 bool log_strip(char c)
@@ -141,6 +144,11 @@ bool log_strip(char c)
 
 void log_printf(const char *format, ...)
 {
+    if (fp == NULL)
+    {
+        return;
+    }
+
     char *line;
 
     va_list(args);
@@ -155,8 +163,11 @@ void log_printf(const char *format, ...)
 
 void log_putc(char c)
 {
-    if (fp != NULL)
+    if (fp == NULL)
     {
+        return;
+    }
+
     if (option.log_strip)
     {
         if (!log_strip(c))
@@ -169,13 +180,14 @@ void log_putc(char c)
         fputc(c, fp);
     }
 }
-}
 
 void log_close(void)
 {
     if (fp != NULL)
     {
         fclose(fp);
+        fp = NULL;
+        log_filename = NULL;
     }
 }
 
@@ -183,15 +195,12 @@ void log_exit(void)
 {
     if (option.log)
     {
+        tio_printf("Saved log to file %s", log_filename);
         log_close();
     }
+}
 
-    if (log_error)
+const char *log_get_filename(void)
 {
-        tio_error_printf("Could not open log file %s (%s)", option.log_filename, strerror(errno));
-    }
-    else if (option.log)
-    {
-        tio_printf("Saved log to file %s", option.log_filename);
-    }
+    return log_filename;
 }

src/log.h

@@ -21,8 +21,9 @@
 
 #pragma once
 
-void log_open(const char *filename);
+int log_open(const char *filename);
 void log_printf(const char *format, ...);
 void log_putc(char c);
 void log_close(void);
 void log_exit(void);
+const char * log_get_filename(void);

src/options.c

@@ -38,6 +38,7 @@
 #include "rs485.h"
 #include "timestamp.h"
 #include "alert.h"
+#include "log.h"
 
 enum opt_t
 {
@@ -216,7 +217,7 @@ void options_print()
     if (option.map[0] != 0)
         tio_printf(" Map flags: %s", option.map);
     if (option.log)
-        tio_printf(" Log file: %s", option.log_filename);
+        tio_printf(" Log file: %s", log_get_filename());
     if (option.socket)
         tio_printf(" Socket: %s", option.socket);
 }

src/tty.c

@@ -80,6 +80,7 @@
 #define KEY_B 0x62
 #define KEY_C 0x63
 #define KEY_E 0x65
+#define KEY_F 0x66
 #define KEY_G 0x67
 #define KEY_H 0x68
 #define KEY_L 0x6C
@@ -414,6 +415,7 @@ void handle_command_sequence(char input_char, char previous_char, char *output_c
                 tio_printf(" ctrl-%c b       Send break", option.prefix_key);
                 tio_printf(" ctrl-%c c       Show configuration", option.prefix_key);
                 tio_printf(" ctrl-%c e       Toggle local echo mode", option.prefix_key);
+                tio_printf(" ctrl-%c f       Toggle log to file", option.prefix_key);
                 tio_printf(" ctrl-%c g       Toggle serial port line", option.prefix_key);
                 tio_printf(" ctrl-%c h       Toggle hexadecimal mode", option.prefix_key);
                 tio_printf(" ctrl-%c l       Clear screen", option.prefix_key);
@@ -443,6 +445,22 @@ void handle_command_sequence(char input_char, char previous_char, char *output_c
                 tio_printf(" RI : %s", (state & TIOCM_RI) ? "HIGH" : "LOW");
                 break;
 
+            case KEY_F:
+                if (option.log)
+                {
+                    log_close();
+                    option.log = false;
+                }
+                else
+                {
+                    if (log_open(option.log_filename) == 0)
+                    {
+                        option.log = true;
+                    }
+                }
+                tio_printf("Switched log to file %s", option.log ? "on" : "off");
+                break;
+
             case KEY_G:
                 tio_printf("Please enter which serial line number to toggle:");
                 tio_printf(" DTR (0)");