/*
  Like the csh builtin time, but from any shell
  Copyright 2008, David Bremner 
  Distributed under the new BSD license
*/

#include <stdio.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <stdarg.h>
#include <time.h>
#include <stdio.h>

#define errcheck(e) if ((long)(e)==-1L){ perror(progname);exit(1);}
#define errcheck2(s,e) if ((long)(e)==-1L){ fprintf(stderr,"%s:",progname);\
					  perror(s);exit(1);}
#define double_time(t) ((double)(t.tv_sec)+(double)(t.tv_usec)/1000000) 


#if 1 
#define fmttime(buf,timer) strftime(buf,sizeof(buf),"%d/%m/%y %T",localtime(timer))
#else
#define fmttime(buf,timer) cftime(buf,"%d/%m/%y %T",timer)
#endif

static  pid_t child_pid;
void shutdown_rmon();
void ptimes();
void job_done();
void errlog(char *,...);

static char* progname;

int main(int argc,char *argv[])
{
  int status;
  
  progname=argv[0];
  

  /* 
     Set up signal handlers:
     SIGTERM,SIGINT: Shutdown gracefully
     We use sysv signal handling here, in the hopes that it will 
     work on both Irix and SunOS
     */

  errcheck(signal(SIGTERM,shutdown_rmon));
  errcheck(signal(SIGINT,shutdown_rmon));

  

  errcheck(child_pid=fork());
  
  
  if (!child_pid)
    {
      /* Create a new process group so that we can kill grandchildren */
      errcheck2("setpgid",setpgid(0,0));

      errcheck(execvp(argv[1],&argv[1]));
    }

  errcheck(waitpid(child_pid, &status,0));

  ptimes();
  exit(0);
}


	    
void print_rusage(struct rusage *r)
{
  fprintf(stderr,"%0.3fu %0.3fs %ldKb %ld flts %ld swaps %ld blks-in %ld blks-out\n",
	  double_time(r->ru_utime),
	  double_time(r->ru_stime),
	  r->ru_maxrss,r->ru_majflt,r->ru_nswap,
	  r->ru_inblock,r->ru_oublock);
}


 
void shutdown_rmon()
{
  int status;
  
  errlog("shutting down\n\n");
  errcheck(kill(-1*child_pid,SIGTERM));
  errcheck(waitpid(child_pid, &status,0));
  ptimes();
  exit(1);
}

void ptimes()
{
  struct rusage rusage;
  getrusage(RUSAGE_CHILDREN,&rusage);
  print_rusage(&rusage);
}

void errlog(char *format,...)
{
  va_list args;
  char buf[80];
  time_t t;
  
  va_start(args,format);
  
  t=time(0);
  fmttime(buf,&t);
  fprintf(stderr,"%s: <%s> ",progname,buf);
  
  vfprintf(stderr, format, args);
  va_end(args);
}