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From: carolyn@cbmvax.UUCP (Carolyn Scheppner CATS)
Newsgroups: comp.sys.amiga
Subject: Re: How can I get to the command search path?
Message-ID: <2810@cbmvax.UUCP>
Date: Tue, 17-Nov-87 19:18:20 EST
Article-I.D.: cbmvax.2810
Posted: Tue Nov 17 19:18:20 1987
Date-Received: Fri, 20-Nov-87 04:28:55 EST
References: <1538@tut.cis.ohio-state.edu>
Reply-To: carolyn@cbmvax.UUCP (Carolyn Scheppner CATS)
Organization: Commodore Technology, West Chester, PA
Lines: 229
Keywords: which

In article <1538@tut.cis.ohio-state.edu> mills-c@pike.cis.ohio-state.edu (Chris Mills) writes:
>
>I'm trying to write a program which, among other things, will do command and
>filename completion on the Amiga.  What I need to know is how do I get at
>the search path (given by the PATH command)?  I need to be able to search
>all the directories from the current dir down to C:.

   I have lots of paths set up on my A2000, and recently got annoyed because
I forgot where I had put a command I needed to update.  So I wrote this.
It contains code to search paths and to build full path names.

-------

/*
 *  which.c  ---  C. Scheppner  CBM  11/87
 *
 *     Usage:  which commandname
 *     Tells you the path to that command
 */

#include <exec/types.h>
#include <exec/memory.h>
#include <libraries/dos.h>
#include <libraries/dosextens.h>

#define SBUFSZ 256
#define CBUFSZ 80

extern BOOL getPath();

struct Path
   {
   BPTR  path_Next;
   LONG  path_Lock;
   };

main(argc,argv)
int argc;
char **argv;
   {
   struct Process *proc;
   struct CommandLineInterface *cli;
   struct Path *path;
   struct FileInfoBlock *fib;
   APTR oldWindowPtr;
   LONG lock, startcd;
   BOOL Found, InitialCD, FullPath;
   int  i;
   char *command, sbuf[SBUFSZ], cbuf[CBUFSZ];

   /* Fail from WB, give usage from CLI if command name not passed */
   if(argc == 0)  exit(RETURN_ERROR);
   if((argc != 2)||(*argv[1]=='?'))
      printf("Usage: which commandname\n"), exit(RETURN_OK);
   command = argv[1];

   /* Fail if not CLI process */
   proc = (struct Process *)FindTask(NULL);
   cli = (struct CommandLineInterface *)(proc->pr_CLI << 2);
   if(!cli)  exit(RETURN_ERROR);

   /* Allocate a FileInfoBlock - must be longword aligned */
   if(!(fib=(struct FileInfoBlock *)
     AllocMem(sizeof(struct FileInfoBlock),MEMF_PUBLIC|MEMF_CLEAR)))
      printf("Not enough memory\n"), exit(RETURN_FAIL);

   /* Save old WindowPtr, and disable volume requesters */
   oldWindowPtr = proc->pr_WindowPtr;
   proc->pr_WindowPtr = (APTR)-1L;

   /* Were we given full path in command name ? */
   for(FullPath = FALSE, i=0; i<strlen(command); i++)
     {
     if(command[i] == ':')
        {
        FullPath = TRUE;
        break;
        }
     }

   /* Check current directory */
   if(Found = getPath(command,fib,sbuf))
      {
      if((!FullPath)&&(command[0]))  strcpy(sbuf,command);
      }

   /* Check paths */
   if((!Found)&&(!FullPath))
      {
      InitialCD = TRUE;
      /* Follow the BPTR path list */
      for(path = (struct Path *) BADDR(cli->cli_CommandDir);
          (path) && (!Found);
            path = (struct Path *) BADDR(path->path_Next))
         {
         /* CD to each path */
         lock = CurrentDir(path->path_Lock);
         if(InitialCD)  startcd = lock, InitialCD = FALSE;

         /* See if command is there */
         Found = getPath(command,fib,sbuf);
         }
      /* If we CD'd anywhere, restore initial CD */
      if(! InitialCD)  CurrentDir(startcd);
      }

   /* Check C: */
   if((!Found)&&(!FullPath))
      {
      strcpy(cbuf,"C:");
      strcpy(&cbuf[2],command);
      if(Found = getPath(cbuf,fib,sbuf))  strcpy(sbuf,cbuf);
      }

   if(Found)  printf("%s\n",sbuf);
   else  printf("%s Not Found\n",command);

   /* Re-enable volume requesters */
   proc->pr_WindowPtr = oldWindowPtr;
   /* We wouldn't have got here if we hadn't allocated this */
   FreeMem(fib, sizeof(struct FileInfoBlock));

   /* Return warning if not found */
   exit(Found ? RETURN_OK : RETURN_WARN);
   }


BOOL
getPath(command,fib,buf)
char *command;
struct FileInfoBlock *fib;
char *buf;
   {
   LONG lock;
   BOOL Success = FALSE;

   if(lock = Lock(command,ACCESS_READ))
      {
      if(Examine(lock,fib))
         {
         Success = TRUE;
         buildPath(lock,fib,buf);
         }
      UnLock(lock);
      }
   return(Success);
   }


buildPath(inlock,fib,buf)
LONG inlock;
struct FileInfoBlock *fib;
char *buf;
   {
   int i;
   LONG lock,oldlock;
   BOOL MyOldLock = FALSE;

   buf[0] = NULL;
   lock = inlock;

   while(lock)
      {
      if(Examine(lock,fib))
         {
         if(fib->fib_FileName[0] > ' ')
            {
            if(buf[0]) insert(buf,"/");
            insert(buf,fib->fib_FileName);
            }
         }
      oldlock = lock;
      lock = ParentDir(lock);
      if(MyOldLock)  UnLock(oldlock);
      else           MyOldLock = TRUE;
      }

   if(fib->fib_FileName[0] > ' ')
      {
      for(i=0; i<(strlen(buf)); i++)
         {
         if(buf[i] == '/')
            {
            buf[i] = ':';
            break;
            }
         }
      }
   else  insert(buf,"RAM:");

   return(strlen(buf));
   }

insert(buf,s)
char *buf,*s;
   {
   char tmp[SBUFSZ];

   strcpy(tmp,buf);
   strcpy(buf,s);
   strcpy(&buf[strlen(s)],tmp);
   }

strlen(s)
char *s;
   {
   int i = 0;
   while(*s++) i++;
   return(i);
   }


strcpy(to,from)
char *to, *from;
   {
   do
      {
      *to++ = *from;
      }
   while(*from++);
   }

/* end */
-- 
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Carolyn Scheppner -- CATS   >>Commodore Amiga Technical Support<<
                     UUCP  ...{allegra,ihnp4,rutgers}!cbmvax!carolyn 
                     PHONE 215-431-9180
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