how to use system function to execute the script

Chris Johns chrisj at rtems.org
Fri Jun 22 05:07:05 UTC 2018


On 22/06/2018 14:44, bin.wang at qkmtech.com wrote:
> hi everyone:
> 
> i want to use the "system()" to execute the script. but do not has output
> 
> first i want to use "system()" to execute the shell cmd, but alse have no output
> 
> the test code is as followed:
> 
>     system("ls -l");
>     system("joel /flash/script/spdloop_1");    //
>  "/flash/script/spdloop_1"----------this is the  script file path in the filesystem 
>   

RTEMS is a single address space, single process OS so you can not exec another
process. You can call the shell command handler from any thread. Make sure you
have enough stack for the thread.

Try something like:

int run_shell_command(const char* cmd)
{
  #define CMD_MAX_ARGS (20)
  char* cmd_argv = strdup(cmd);
  int   argc;
  char* argv[CMD_MAX_ARGS];
  int   r;

  if (cmd_argv == NULL) {
    fprintf(stderr, "shell: command: no memory: %s", cmd);
    return 1;
  }

  if (rtems_shell_make_args(cmd_argv, &argc, argv, CMD_MAX_ARGS) < 0) {
    fprintf(stderr, "shell: command: arg parse: %s", cmd);
    free(cmd_argv);
    return 1;
  }

  r = rtems_shell_execute_cmd(argv[0], argc, argv);
  free(cmd_argv);
  return r;
}

Chris


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