/* 
* File:    main.c
* CVS:     $Id: main.c,v 1.4 2005/06/17 11:55:18 pek Exp $
* Author:  Philip Mucci
*          mucci@cs.utk.edu
* Mods:    Per Ekman
*          pek@pdc.kth.se
*/

#include <libgen.h>
#include "iotrack.h"

char *usage_long[] = {"Usage: [-hvtnd] [-f [prefix]] -- <cmd> <cmd options>",
	" -h\t\tPrint this message.",
	" -v\t\tPrint version information.",
	" -t\t\tEnable monitoring of multiple threads.",
	" -n\t\tDo not follow fork()'s.",
	" -d\t\tEnable debugging output.",
	" -f[prefix]\tOutput to <prefix><cmd>.iotrack.<host>.<pid>.<tid>.",
	"",
	"This is OPEN SOURCE SOFTWARE written by Per Ekman",
	"of the Parallel Center for Computation, Royal Institute",
	"of Technology, Stockholm, Sweden and Philip Mucci of the",
	"Innovative Computing Laboratory at the University of",
	"Tennessee, Knoxville.\n",
	"See WEB-PAGE for further information.",
	"Email bug reports to: EMAIL-ADDRESS"
};


static int debug = 0;

static char *parse_args(int my_argc, char **my_argv, char **cmd, char ***cmd_argv, char *preload_env, char *preload_sep)
{
  int c, i;
  static char option_string[PATH_MAX] = "";

#if defined(linux) || defined(sun)
   strcpy(preload_env,"LD_PRELOAD");
   *preload_sep = ' ';
#elif defined(sgi)
   strcpy(preload_env,"_RLD_LIST");
   *preload_sep = ':';
#endif

  if (my_argc)
    {
      while (1)
	{
	  c = getopt(my_argc, my_argv, "hvtndf::");
	  if (c == -1)
	    break;
	  
	  switch(c)
	    {
	    case 'v':
	      printf("iotrack version %s\n",IOTRACK_VERSION);
	      exit(0);
	      break;
            case 'h':
	      for (i = 0; i < (sizeof usage_long / sizeof usage_long[0]); 
                   i++) {
                puts(usage_long[i]);
              }
	      exit(0);
	      break;
	    case 'n':
	      strcat(option_string,"NOFORK,");
	      break;
	    case 't':
	      strcat(option_string,"THREADS,");
	      break;
	    case 'd':
	      strcat(option_string,"DEBUG,");
	      debug = 1;
	      break;
	    case 'f':
	      {
		if (optarg == NULL)
		  strcat(option_string,"FILE,");
		else
		  {
		    strcat(option_string,"FILE=");
		    strcat(option_string,optarg);
		    strcat(option_string,",");
		  }
	      }
	      break;
	      default:
	    error:
	        puts(usage_long[0]);
	        fprintf(stderr,"Try `%s -h' for more information.\n",my_argv[0]);
		exit(1);
	    }
	}
    }

  /* Construct argv for the fork/exec pair later on. */

  if (my_argv[optind] == NULL)
    {
      fprintf(stderr,"%s: no command given\n",my_argv[0]);
      goto error;
    }
  {
    char **tmp_my_argv = (char **)malloc((my_argc-optind+1)*sizeof(char *));
    for (i=optind;i<my_argc;i++)
      tmp_my_argv[i-optind] = strdup(my_argv[i]);
    tmp_my_argv[i-optind] = NULL;
    *cmd_argv = tmp_my_argv;
    *cmd = strdup(tmp_my_argv[0]);
  }
  return(option_string);
}

int main(int argc, char **argv)
{
  static char tmpstr[PATH_MAX] = "";
  static char tmpstr2[PATH_MAX] = "";
  char preload_env[PATH_MAX];
  char preload_sep;
  char libpath[PATH_MAX];
  char *cmd = NULL;
  char **cmd_argv = NULL;
  char *optstr = parse_args(argc,argv,&cmd,&cmd_argv,preload_env,&preload_sep);

  if ((optstr == NULL) || (strlen(optstr) == 0))
	sprintf(tmpstr,"%s= ",IOTRACK_ENV);
  else
	sprintf(tmpstr,"%s=%s",IOTRACK_ENV,optstr);

  /* set libpath to the path of this binary */
  if ( (readlink("/proc/self/exe", tmpstr2, sizeof tmpstr2)) < 0) {
	  perror("Failed to read /proc/self/exe link");
	  exit(1);
  }
  strncpy(libpath, dirname(tmpstr2), sizeof libpath);


#if defined(linux)
  setenv(IOTRACK_ENV,optstr,1);
#else
  putenv(tmpstr);
#endif

  if (getenv(preload_env)) 
    sprintf(tmpstr2,"%s=%s/iowrap.so%c%s",preload_env,libpath, preload_sep,getenv(preload_env)); 
  else 
#if defined(sgi)
    sprintf(tmpstr2,"%s=./iowrap.so%cDEFAULT",preload_env,preload_sep,preload_sep); 
#else
    sprintf(tmpstr2,"%s=%s/iowrap.so", preload_env, libpath); 
#endif
  putenv(tmpstr2); 

  if (fork()==0)
    {
      if (execvp(cmd,cmd_argv) == -1)
	{
	  fprintf(stderr,"Error exec'ing %s: %s\n",cmd,strerror(errno));
	  exit(1);
	}
    }
  else
    {
      int status;
      wait(&status);
      exit(WEXITSTATUS(status));
    }

  exit(0);
}