Add list serial devices feature

For convenience, add a --list-devices option which lists the available
serial devices.

README.md

@@ -29,6 +29,7 @@ The command-line interface is straightforward as reflected in the output from
       -n, --no-autoconnect        Disable automatic connect
       -e, --local-echo            Do local echo
       -t, --timestamp             Timestamp lines
+      -i, --list-devices          List available serial devices
       -l, --log <filename>        Log to file
       -m, --map <flags>           Map special characters
       -v, --version               Display version

man/tio.1

@@ -61,6 +61,11 @@ Enable local echo.
 
 Timestamp lines.
 
+.TP
+.BR \-t ", " \-\-list\-devices
+
+List available serial devices.
+
 .TP
 .BR \-l ", " "\-\-log " \fI<filename>
 

src/bash-completion/tio.in

@@ -21,6 +21,7 @@ _tio()
           -m --map \
           -v --version \
           -t --timestamp \
+          -i --list-devices \
           -h --help"
 
     #  Complete the arguments to the options.
@@ -70,6 +71,10 @@ _tio()
             COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
             return 0
             ;;
+        -i | --list-devices)
+            COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+            return 0
+            ;;
         -v | --version)
             COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
             return 0

src/include/tio/options.h

@@ -41,6 +41,7 @@ struct option_t
     bool log;
     bool local_echo;
     bool timestamp;
+    bool list_devices;
     const char *log_filename;
     const char *map;
 };

src/include/tio/tty.h

@@ -48,5 +48,6 @@ void stdin_restore(void);
 void tty_configure(void);
 int tty_connect(void);
 void tty_wait_for_device(void);
+void list_serial_devices(void);
 
 #endif

src/main.c

@@ -31,7 +31,7 @@
 
 int main(int argc, char *argv[])
 {
-    int status;
+    int status = 0;
 
     /* Install error exit handler */
     atexit(&error_exit);
@@ -39,6 +39,13 @@ int main(int argc, char *argv[])
     /* Parse options */
     parse_options(argc, argv);
 
+    /* List available serial devices */
+    if (option.list_devices)
+    {
+        list_serial_devices();
+        return status;
+    }
+
     /* Configure tty device */
     tty_configure();
 

src/options.c

@@ -47,6 +47,7 @@ struct option_t option =
     .log = false,
     .local_echo = false,
     .timestamp = false,
+    .list_devices = false,
     .log_filename = "",
     .map = ""
 };
@@ -65,6 +66,7 @@ void print_help(char *argv[])
     printf("  -n, --no-autoconnect        Disable automatic connect\n");
     printf("  -e, --local-echo            Do local echo\n");
     printf("  -t, --timestamp             Timestamp lines\n");
+    printf("  -i, --list-devices          List available serial devices\n");
     printf("  -l, --log <filename>        Log to file\n");
     printf("  -m, --map <flags>           Map special characters\n");
     printf("  -v, --version               Display version\n");
@@ -115,6 +117,7 @@ void parse_options(int argc, char *argv[])
             {"no-autoconnect", no_argument,       0, 'n'},
             {"local-echo",     no_argument,       0, 'e'},
             {"timestamp",      no_argument,       0, 't'},
+            {"list-devices",   no_argument,       0, 'i'},
             {"log",            required_argument, 0, 'l'},
             {"map",            required_argument, 0, 'm'},
             {"version",        no_argument,       0, 'v'},
@@ -126,7 +129,7 @@ void parse_options(int argc, char *argv[])
         int option_index = 0;
 
         /* Parse argument using getopt_long */
-        c = getopt_long(argc, argv, "b:d:f:s:p:o:netl:m:vh", long_options, &option_index);
+        c = getopt_long(argc, argv, "b:d:f:s:p:o:netil:m:vh", long_options, &option_index);
 
         /* Detect the end of the options */
         if (c == -1)
@@ -180,6 +183,10 @@ void parse_options(int argc, char *argv[])
                 option.timestamp = true;
                 break;
 
+            case 'i':
+                option.list_devices = true;
+                break;
+
             case 'l':
                 option.log = true;
                 option.log_filename = optarg;
@@ -214,6 +221,11 @@ void parse_options(int argc, char *argv[])
         }
     }
 
+    if (option.list_devices)
+    {
+        return;
+    }
+
     /* Assume first non-option is the tty device name */
     if (optind < argc)
         option.tty_device = argv[optind++];

src/tty.c

@@ -36,6 +36,7 @@
 #include <stdbool.h>
 #include <errno.h>
 #include <time.h>
+#include <dirent.h>
 #include "config.h"
 #include "tio/tty.h"
 #include "tio/print.h"
@@ -48,6 +49,8 @@
 extern int setspeed2(int fd, int baudrate);
 #endif
 
+#define PATH_SERIAL_DEVICES "/dev/serial/by-id/"
+
 static struct termios tio, tio_old, stdout_new, stdout_old, stdin_new, stdin_old;
 static unsigned long rx_total = 0, tx_total = 0;
 static bool connected = false;
@@ -841,3 +844,21 @@ error_read:
 error_open:
     return TIO_ERROR;
 }
+
+void list_serial_devices(void)
+{
+    DIR *d;
+    struct dirent *dir;
+    d = opendir(PATH_SERIAL_DEVICES);
+
+    if (d)
+    {
+        while ((dir = readdir(d)) != NULL)
+        {
+            if ((strcmp(dir->d_name, ".")) && (strcmp(dir->d_name, "..")))
+                printf("%s%s\n", PATH_SERIAL_DEVICES, dir->d_name);
+        }
+
+        closedir(d);
+    }
+}