Add option '--exec <command>' for running shell command

Runs shell command with I/O redirected to device.

TODO

@@ -19,16 +19,6 @@
    key navigation left/right and insert/overwrite support. Also history browsing
    pressing up/down.
 
- * Support for running external command
-
-   Add key command e.g. 'ctrl-t r' which prompts user to run external command.
-   The command will be run in a process which stdin/stdout is redirected to the
-   serial port.
-
-   This is the first step towards maybe also adding automatic support for
-   x/y/zmodem data transfer protocols by calling external programs such as
-   rb/sb, rx/sx, rz/sz, etc.
-
  * Allow tio to connect to socket
 
    After some more consideration I think it makes sense to support connecting to a

man/tio.1.in

@@ -358,6 +358,11 @@ Run script on connect once, always, or never.
 
 Default value is "always".
 
+.TP
+.BR "\-\-exec \fI<command>
+
+Execute shell command with I/O redirected to device
+
 .TP
 .BR \-v ", " \-\-version
 
@@ -571,6 +576,9 @@ Run script from string
 Run script from file
 .IP "\fBscript-run"
 Run script on connect
+.IP "\fBexec"
+Execute shell command with I/O redirected to device
+
 
 .SH "CONFIGURATION FILE EXAMPLES"
 

src/bash-completion/tio.in

@@ -45,6 +45,7 @@ _tio()
              --script \
              --script-file \
              --script-run \
+             --exec \
           -v --version \
           -h --help"
 
@@ -179,6 +180,10 @@ _tio()
             COMPREPLY=( $(compgen -W "once always never"  -- ${cur}) )
             return 0
             ;;
+        --exec)
+            COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+            return 0
+            ;;
         -v | --version)
             COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
             return 0

src/configfile.c

@@ -282,6 +282,7 @@ static void config_parse_keys(GKeyFile *key_file, char *group)
         g_free((void *)string);
         string = NULL;
     }
+    config_get_string(key_file, group, "exec", &option.exec, NULL);
     config_get_string(key_file, group, "prefix-ctrl-key", &string, NULL);
     if (string != NULL)
     {

src/misc.c

@@ -33,6 +33,7 @@
 #include <time.h>
 #include <errno.h>
 #include <sys/poll.h>
+#include <sys/wait.h>
 #include <termios.h>
 #include <fnmatch.h>
 #include "error.h"
@@ -199,3 +200,61 @@ bool match_patterns(const char *string, const char *patterns)
     free(patterns_copy);
     return false;
 }
+
+// Function that forks subprocess, redirects its stdin and stdout to the
+// specified filedescriptor, and runs command.
+int execute_shell_command(int fd, const char *command)
+{
+    pid_t pid;
+    int status;
+
+    // Fork a child process
+    pid = fork();
+    if (pid == -1)
+    {
+        // Error occurred
+        tio_error_print("fork() failed (%s)", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+    else if (pid == 0)
+    {
+        // Child process
+
+        tio_printf("Executing shell command '%s'", command);
+
+        // Redirect stdout and stderr to the file descriptor
+        if (dup2(fd, STDOUT_FILENO) == -1 || dup2(fd, STDERR_FILENO) == -1)
+        {
+            tio_error_print("dup2() failed (%s)", strerror(errno));
+            exit(EXIT_FAILURE);
+        }
+
+        // Execute the shell command
+        execl("/bin/sh", "sh", "-c", command, (char *)NULL);
+
+        // If execlp() returns, it means an error occurred
+        perror("execlp");
+        tio_error_print("execlp() failed (%s)", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+    else
+    {
+        // Parent process
+
+        // Wait for the child process to finish
+        waitpid(pid, &status, 0);
+
+        if (WIFEXITED(status))
+        {
+            tio_printf("Command exited with status %d", WEXITSTATUS(status));
+            return WEXITSTATUS(status);
+        }
+        else
+        {
+            tio_error_printf("Child process exited abnormally\n");
+            return -1;
+        }
+    }
+
+    return 0;
+}

src/misc.h

@@ -34,3 +34,4 @@ char *base62_encode(unsigned long num);
 int read_poll(int fd, void *data, size_t len, int timeout);
 double get_current_time(void);
 bool match_patterns(const char *string, const char *patterns);
+int execute_shell_command(int fd, const char *command);

src/options.c

@@ -69,6 +69,7 @@ enum opt_t
     OPT_EXCLUDE_DEVICES,
     OPT_EXCLUDE_DRIVERS,
     OPT_EXCLUDE_TIDS,
+    OPT_EXEC,
 };
 
 /* Default options */
@@ -121,6 +122,7 @@ struct option_t option =
     .exclude_tids = NULL,
     .hex_n_value = 0,
     .vt100 = false,
+    .exec = NULL,
 };
 
 void option_print_help(char *argv[])
@@ -167,6 +169,7 @@ void option_print_help(char *argv[])
     printf("      --script <string>                  Run script from string\n");
     printf("      --script-file <filename>           Run script from file\n");
     printf("      --script-run once|always|never     Run script on connect (default: always)\n");
+    printf("      --exec <command>                   Execute shell command with I/O redirected to device\n");
     printf("  -v, --version                          Display version\n");
     printf("  -h, --help                             Display help\n");
     printf("\n");
@@ -815,6 +818,7 @@ void options_parse(int argc, char *argv[])
             {"script",               required_argument, 0, OPT_SCRIPT              },
             {"script-file",          required_argument, 0, OPT_SCRIPT_FILE         },
             {"script-run",           required_argument, 0, OPT_SCRIPT_RUN          },
+            {"exec",                 required_argument, 0, OPT_EXEC                },
             {"version",              no_argument,       0, 'v'                     },
             {"help",                 no_argument,       0, 'h'                     },
             {"complete-profiles",    no_argument,       0, OPT_COMPLETE_PROFILES   },
@@ -985,6 +989,10 @@ void options_parse(int argc, char *argv[])
                 option_parse_script_run(optarg, &option.script_run);
                 break;
 
+            case OPT_EXEC:
+                option.exec = optarg;
+                break;
+
             case 'v':
                 printf("tio v%s\n", VERSION);
                 exit(EXIT_SUCCESS);

src/options.h

@@ -96,6 +96,7 @@ struct option_t
     char *exclude_tids;
     int hex_n_value;
     bool vt100;
+    char *exec;
 };
 
 extern struct option_t option;

src/tty.c

@@ -2277,6 +2277,12 @@ int tty_connect(void)
         exit(EXIT_SUCCESS);
     }
 
+    if (option.exec != NULL)
+    {
+        int status = execute_shell_command(device_fd, option.exec);
+        exit(status);
+    }
+
     /* Input loop */
     while (true)
     {