Path: utzoo!attcan!uunet!mcvax!unido!fauern!faui44!immd3.informatik.uni-erlangen.de!rtregn
From: rtregn@immd3.informatik.uni-erlangen.de (Robert Regn)
Newsgroups: comp.os.minix
Subject: Re: Float f'ns & system calls
Message-ID: <643@faui44.informatik.uni-erlangen.de>
Date: 29 Sep 88 12:21:36 GMT
References: <273@gara.une.oz>
Organization: IMMD III, University of Erlangen, W-Germany
Lines: 212

wtoomey@gara.une.oz (Warren Toomey):
> 
> Also, a friend of mine, Callum Gibson, is writing a tcsh-like shell for
> his Honours project, and I'd love to port it to Minix but there's a few
> system/library calls missing. Could anybody who has the code for the
> calls below post it to me and/or the net:
> 
A very good idea!! 		In the right place my answer:

> closedir					see below
> execv		(Done by Terrance Holm?)	In Minix since 1.1
> execve	(Done by Terrance Holm?)	In Minix since 1.1
> feof		(A macro somewhere?)		Yes in stdio.h
> fputc		(Declared in 'fputs'?)		A macro in stdio.h, same as putc
> free		(Declared in 'malloc'?)		In Minix since 1.1
> getcwd	(Done by Terrance Holm?)	see below
> getwd						see below
> isdigit	(A macro somewhere?)		Yes, In Minix since 1.1
> localtime	(Declared in 'ctime'?)		Yes, in 1.2
> lstat		(Declared in 'stat'?)		see below
> opendir					see below
> pclose	(Declared in 'popen'?)		Yes, in 1.2
> readdir					see below
> realloc	(Declared in 'malloc'?)		Yes, already in 1.1
> setpgrp					see below
> 


A problem are the directory system calls opendir, closedir and  readdir
(standard in BSD systems). Try to get the message 
581@ndsuvax.uucp:Subject: Directory(3) library calls for MINIX

from a minix newsserver (I don't have it). Probably the readdir in traverse
will suffer and  opendir, closedir should be dummies. Look at the code of tcsh.

I think, setpgrp is not existent in Minix yet. Use a dummy routine which
calls signal to ignore int and quit. That works also.

Lstat is only useful if we have symbolic links. Minix don't have. Use 
#define lstat stat

getwd i have never heard. See on the code or ask Callum, what should it do.
getcwd - get current working directory
posted from Terrence Holm in Aug 88. Shell script below

I wish you success and like to get a copy of the source. 

				Robert Regn
				rtregn.faui32.uucp
-------------------------------------------------------------------------
echo x - getcwd.c
gres '^X' '' > getcwd.c << '/'
X/*  getcwd(3)
X *
X *  Author: Terrence W. Holm          Aug. 1988
X *
X *  Directly derived from Adri Koppes' pwd(1).
X */
X
X#include <sys/types.h>
X#include <sys/stat.h>
X#include <sys/dir.h>
X#include <errno.h>
X
X#define  NULL         (char *) 0
X#define  O_RDONLY     0
X#define  DIRECT_SIZE  (sizeof (struct direct))
X#define  PATH_MAX     127
X
Xextern char *rindex();
X
Xextern int errno;
X
X
Xchar *getcwd( buffer, size )
X  char *buffer;
X  int   size;
X
X  {
X  static char path[ PATH_MAX + 1 ];
X  struct stat current;
X
X  if ( buffer == NULL  ||  size == 0 )
X    {
X    errno = EINVAL;
X    return( NULL );
X    }
X
X  path[0] = '\0';
X
X  /*  Get the inode for the current directory  */
X   
X  if ( stat( ".", &current ) == -1 )
X    return( NULL );
X
X  if ( (current.st_mode & S_IFMT) != S_IFDIR )
X    return( NULL );
X
X
X  /*  Run backwards up the directory tree, grabbing 	*/
X  /*  directory names on the way.			*/
X
X  while (1)
X    {
X    struct stat parent;
X    struct direct d;
X    int same_device = 0;
X    int found = 0;
X    int fd;
X
X    /*  Get the inode for the parent directory  */
X
X    if ( chdir( ".." ) == -1 )
X	return( NULL );
X
X    if ( stat( ".", &parent ) == -1 )
X	return( NULL );
X
X    if ( (parent.st_mode & S_IFMT) != S_IFDIR )
X	return( NULL );
X
X    if ( current.st_dev == parent.st_dev )
X	same_device = 1;
X
X
X    /*  At the root, "." is the same as ".."  */
X
X    if ( same_device  &&  current.st_ino == parent.st_ino )
X	break;
X
X
X    /*  Search the parent directory for the current entry  */
X
X    if ( (fd = open( ".", O_RDONLY )) == -1 )
X	return( NULL );
X
X    while ( ! found  &&  read(fd, &d, DIRECT_SIZE) == DIRECT_SIZE )
X	{
X	if ( same_device )
X	    {
X	    if ( current.st_ino == d.d_ino )
X		found = 1;
X	    }
X	else
X	    {
X	    static char temp_name[ DIRSIZ + 1 ];
X	    static struct stat dir_entry;
X
X	    temp_name[0] = '\0';
X	    strncat( temp_name, d.d_name, DIRSIZ );
X
X	    if ( stat( temp_name, &dir_entry ) == -1 )
X		{
X		close( fd );
X		return( NULL );
X		}
X
X	    if ( current.st_dev == dir_entry.st_dev  &&
X	         current.st_ino == dir_entry.st_ino )
X		found = 1;
X	    }
X	}
X
X    close( fd );
X
X    if ( ! found )
X    	return( NULL );
X
X    if ( strlen(path) + DIRSIZ + 1 > PATH_MAX )
X	{
X	errno = ERANGE;
X	return( NULL );
X	}
X
X    strcat( path, "/" );
X    strncat( path, d.d_name, DIRSIZ );
X 
X    current.st_dev = parent.st_dev;
X    current.st_ino = parent.st_ino;
X    }
X
X
X  /*  Copy the reversed path name into <buffer>  */
X
X  if ( strlen(path) + 1 > size )
X    {
X    errno = ERANGE;
X    return( NULL );
X    }
X
X  if ( strlen(path) == 0 )
X    {
X    strcpy( buffer, "/" );
X    return( buffer );
X    }
X
X  *buffer = '\0';
X
X  {
X  char *r;
X
X  while ( (r = rindex( path, '/' )) != NULL )
X    {
X    strcat( buffer, r );
X    *r = '\0';
X    }
X  }
X
X  return( buffer );
X  }
/
-------------------------------------------------------------------------