/* ----------------------------------------------------------------
 *	which.c
 *
 *	$Header: /private/postgres/src/utils/fmgr/RCS/which.c,v 1.4 1990/02/12 19:50:02 cimarron Exp $
 * ----------------------------------------------------------------
 */

#include <sys/param.h>
#include <sys/stat.h>


/* This does the equivalent of /bin/which.  That is, given a filename,
** it searches directories named in the environment variable PATH, until
** it finds a file with that filename.
*/
#ifdef linux
#define copy_of(name) (strdup(name))
#else
#define copy_of(name) ((char*) sprintf(malloc(strlen(name)+1), "%s", name))
#endif

static
exists(filename)
  char* filename;
{
  struct stat buffer;
  return(stat(filename, &buffer) != -1);

}

/* The PATH string looks something like this:
**
** .:/u/djones/bin:/usr/local/bin:/usr/mega/bin:/u/mega/bin
**
**
** except probably longer.
*/

char*
which(file)
  char* file;
{

  if(*file == '/') return copy_of(file);

  {  char* search = (char*)getenv("PATH");

     if(search == 0)
       search = ".:~/bin:/usr/mega/bin:/usr/local/bin:/usr/new:/usr/ucb:/usr/bin:/bin:/usr/hosts:/usr/games";

     { register char* ptr = search;
       
       while(*ptr)
	 { char  name[MAXPATHLEN];
	   register char* next = name;
 	   
	   /* copy directory name into [name] */
	   while(*ptr && *ptr != ':') *next++ = *ptr++;
	   if(*ptr) ptr++;
	   
	   *next++ = '/'; /* separates directory name and filename */
	   
	   /* copy filename into [name] */
	   { register char* ptr2 = file;
	     while(*ptr2) *next++ = *ptr2++;
	   }
	   
	   *next = '\0';
	   
	   { char* afile = (char*)(name);
	     if(exists(afile)) return (afile);
	     free(afile);
	   }
	   
	 }
       
     }
     return file;
   }
}

#undef binwhich
#ifdef binwhich
main(argc, argv)
  char** argv;
{

  argc--; argv++;

  while (argc)
    { char* path = which(*argv);
      if(path)
	{
	  printf("%s\n", path);
	  free(path);
	}
      else
	{ char* ptr = search;
	  printf("no %s in ", *argv);
	  while(*ptr)
	    { putchar(*ptr==':' ? ' ' : *ptr);
	      ptr++;
	    }
	  putchar('\n');
	}
      argc--; argv++; 
    }
  exitpg(0);
}
#endif binwhich