#include <unistd.h>

 #include <errno.h>

 

 main( int argc, char ** argv, char ** envp )

 {

               if( setgid(getegid()) ) perror( "setgid" );

               if( setuid(geteuid()) ) perror( "setuid" );

               envp = 0; /* blocks IFS attack on non-bash shells */

               system( "/usr/bin/hg", argv, envp );

               perror( argv[0] );

               return errno;

 }