Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.sysv386
Subject: Re: Retensioning tapes through wt(7) under ISC 3.2.2.1
Keywords: wt(7), QIC-60, retensioning, tape
Message-ID: <1991Apr23.130436.7470@virtech.uucp>
Date: 23 Apr 91 13:04:36 GMT
References: <1991Apr21.174450.26570@gorgon.uucp>
Organization: Virtual Technologies Inc.
Lines: 327

dag@gorgon.uucp (Daniel A. Glasser) writes:
>I have a 60 meg tape drive (TECMAR QT-60i) connected to a Wangtek PC-60
>controller, and it works just fine with the ISC WT driver.  I have been
>retensioning my tapes by booting DOS from a floppy and using the utilities
>that came with the drive.  I would like to do it without rebooting my
>machine.  I've been trying to write a retension utility that uses the
>wt(7)'s documented RETENS command to ioctl(), but seem to be missing

First off, I don't know why you bother to retension the tapes, I have
been using various QIC tapes for several years and have yet to run into
a problem that would be solved by retensioning (so I dont bother anymore)
Yes, I flirt with danger on a daily basis :-)

Anyway, here is the source for a tape command utility that gives
you the capability to do what you want.

#!/bin/sh
# This is a shell archive (produced by shar 3.49)
# To extract the files from this archive, save it to a file, remove
# everything above the "!/bin/sh" line above, and type "sh file_name".
#
# made 04/23/1991 13:03 UTC by cpcahil@virtech
# Source directory /a/corp/src/cmd/tapecmd
#
# existing files will NOT be overwritten unless -c is specified
#
# This shar contains:
# length  mode       name
# ------ ---------- ------------------------------------------
#    596 -r--r--r-- Makefile
#   3831 -r--r--r-- tapecmd.c
#
# ============= Makefile ==============
if test -f 'Makefile' -a X"$1" != X"-c"; then
	echo 'x - skipping Makefile (File already exists)'
else
echo 'x - extracting Makefile (Text)'
sed 's/^X//' << 'SHAR_EOF' > 'Makefile' &&
#
# (c) Copyright 1991 Conor P. Cahill (uunet!virtech!cpcahil).  
# You may copy, distribute, and use this software as long as this
# copyright statement is not removed.
#
#
# This is the Makefile for the tapecmd utility
#
# $Id: Makefile,v 1.2 91/04/23 09:03:03 cpcahil Exp $
#
CC=cc
#DFLAGS=-DDEBUG=40
CFLAGS= -O $(DFLAGS)
LDFLAGS=
LIBS=
INSTDIR=/usr/local/bin
X
SRCS=tapecmd.c
OBJS=$(SRCS:.c=.o)
EXE=tapecmd
X
all: $(EXE)
X
install: $(INSTDIR)/$(EXE)
X
$(INSTDIR)/$(EXE): $(EXE)
X	-rm -f $@.old
X	-mv -f $@ $@.old
X	cp $? $@
X	-rm -f $@.old
X
X
$(EXE): $(OBJS) 
X	$(CC) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)
X
SHAR_EOF
chmod 0444 Makefile ||
echo 'restore of Makefile failed'
Wc_c="`wc -c < 'Makefile'`"
test 596 -eq "$Wc_c" ||
	echo 'Makefile: original size 596, current size' "$Wc_c"
fi
# ============= tapecmd.c ==============
if test -f 'tapecmd.c' -a X"$1" != X"-c"; then
	echo 'x - skipping tapecmd.c (File already exists)'
else
echo 'x - extracting tapecmd.c (Text)'
sed 's/^X//' << 'SHAR_EOF' > 'tapecmd.c' &&
/*
X * (c) Copyright 1990 Conor P. Cahill (uunet!virtech!cpcahil).  
X * You may copy, distribute, and use this software as long as this
X * copyright statement is not removed.
X */
#include <sys/types.h>
#include <sys/wtioctl.h>
#include <sys/termio.h>
X
#include <fcntl.h>
#include <stdio.h>
#include <ctype.h>
X
#define SLEEP_TIME		7
#define TAPE_ERASE		0x01
#define TAPE_RETEN		0x02
#define TAPE_REWIND		0x04
#define TAPEFILE_NOREWIND	"/dev/rnmt0"
#define TAPEFILE_REWIND		"/dev/rmt0"
#define DEFAULT_FILENAME	TAPEFILE_REWIND
X
static char rcs_hdr[] = "$Id: tapecmd.c,v 1.4 91/04/23 09:03:05 cpcahil Exp $";
X
int	nointeract;
X
main(argc,argv)
X	int	  argc;
X	char	**argv;
{
X
X	char		* command;
X	int		  count = 1;
X	extern int	  errno;
X	int		  fd;
X	char		* filename = DEFAULT_FILENAME;
X	int		  numtapes = 1;
X	int		  tape_cmd;
X	int		  tape_count = 0;
X
X	/*
X	 * if silent (no interaction) mode
X	 */
X	if( (argc > 1) && (strcmp(argv[1],"-n")) == 0 )
X	{
X		nointeract = 1;
X		argc--;
X		argv++;
X	}
X
X	switch(argc)
X	{
X		case 2:
X			command = argv[1];
X			break;
X		case 3:	
X			command = argv[1];
X			if( isdigit(argv[2][0]) )
X			{
X				count = atoi(argv[2]);
X			}
X			else
X			{
X				filename = argv[2];
X			}
X			break;
X		case 4:
X			command = argv[1];
X			if( isdigit(argv[2][0]) )
X			{
X				count = atoi(argv[2]);
X				filename = argv[3];
X			}
X			else
X			{
X				filename = argv[2];
X				count = atoi(argv[3]);
X			}
X			break;
X		default:
X			usage(argv[0]);
X			break;
X
X	} /* switch(argc... */
X
X	/*
X 	 * Now check arguments...  
X	 * count must be greater than zero.
X	 */
X
X	if( count <= 0 )
X	{
X		fprintf(stderr,"Illegal count specified %d\n",count);
X		usage(argv[0]);
X	}
X	if( strncmp(command,"ret",3) == 0 )
X	{
X		tape_cmd = TAPE_RETEN;
X	}
X	else if( strncmp(command,"rew",3) == 0)
X	{
X		tape_cmd = TAPE_REWIND;
X		if( strcmp(filename,TAPEFILE_NOREWIND) == 0 )
X		{
X			if( filename != DEFAULT_FILENAME )
X			{
X				fprintf(stderr,"File name changed to %d %s\n",
X						TAPEFILE_REWIND,
X						"to perform rewind");
X			}
X			filename = TAPEFILE_REWIND;
X		}
X	}
X	else if( command[0] == 'e' )
X	{
X		tape_cmd = TAPE_ERASE;
X	}
X	else
X	{
X		fprintf(stderr,"Illegal command: %s\n", command);
X		usage(argv[0]);
X	}
X
X
X	while( count-- > 0 )
X	{
X		if( ! nointeract )
X		{
X			(void) change_tape(++tape_count,tape_cmd);
X		}
X
X		if( (fd=open(filename,O_RDWR)) == -1 )
X		{
X			fprintf(stderr,"Failed to open %s, errno = %d\n",
X					filename, errno);
X			exit(10);
X		}
X
X		if( tape_cmd != TAPE_REWIND )
X		{
X			/*
X			 * make sure the tape has stablized by sleeping a
X		 	 * bit before sending the ioctl
X			 */
X			sleep(SLEEP_TIME);
X			
X			if( ioctl(fd,WTQICMD,tape_cmd) == 1)
X			{
X				fprintf(stderr,"Ioctl failed, errno = %d\n",
X					errno);
X				fprintf(stderr,"Operation may not have %s\n",
X					"succeeded");
X			}
X		}
X
X		close(fd);
X	}
X	exit(0);
}
X
usage(pgm)
X	char	* pgm;
{
X	char	* ptr;
X	char	* strrchr();
X
X	if( (ptr=strrchr(pgm,'/')) != (char *) 0)
X	{
X		pgm = ptr+1;
X	}
X
X	fprintf(stderr,"Usage: %s tape_command [-n] [count] [tapefilename]\n",
X		pgm);
X	fprintf(stderr,"Where tape_command can be: %s\n",
X		"rewind, retension, or erase");
X	fprintf(stderr,"   -n signifies no interaction\n");
X	fflush(stderr);
X	exit(10);
}
X
change_tape(cnt,cmd)
X	int	cnt;
X	int 	cmd;
{
X	char 	  buffer[120];
X	char	* job;
X	char	* suffix;
X
X	switch(cnt)
X	{
X		case 1:
X			suffix = "st";
X			break;
X		case 2:
X			suffix = "nd";
X			break;
X		case 3:
X			suffix = "rd";
X			break;
X		default:
X			suffix = "th";
X			break;
X
X	} /* switch(cnt... */
X
X	switch(cmd)
X	{
X		case TAPE_REWIND:
X			job = "rewind";
X			break;
X
X		case TAPE_RETEN:
X			job = "retension";
X			break;
X
X		default:
X			job = "erase";
X			break;
X
X	} /* switch(cmd... */
X			
X	fprintf(stdout,"Please place the %d%s tape in the drive and\n",
X		cnt, suffix);
X	fprintf(stdout,"press <return> to %s it",job);
X	fflush(stdout);
X
X	(void) ioctl(0,TCFLSH, 0);
X 	(void) read(0,buffer,120);
}
X	
SHAR_EOF
chmod 0444 tapecmd.c ||
echo 'restore of tapecmd.c failed'
Wc_c="`wc -c < 'tapecmd.c'`"
test 3831 -eq "$Wc_c" ||
	echo 'tapecmd.c: original size 3831, current size' "$Wc_c"
fi
exit 0
-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170