Ultrix-3.1/src/cmd/ltf/odm.c
/**********************************************************************
* Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. *
* All Rights Reserved. *
* Reference "/usr/src/COPYRIGHT" for applicable restrictions. *
**********************************************************************/
#ifndef lint
static char *sccsid = "@(#)odm.c 3.0 (ULTRIX) 4/21/86";
#endif lint
/* */
/*
*
* File name:
*
* odm.c
*
* Source file description:
*
* This file contains the various routines used for
* Output Device Management by the Labeled Tape Facility (LTF).
*
* It is used by the LTF in order to centralize those routines
* which are "system" dependant. ie. Ultrix-11 systems do not
* provide the same set of i/o control systems calls as does
* an Ultrix-32 system.
*
*
* Functions:
*
* ceot() Check if hit end of tape
* bsf() Backspace 'n' tape/file mark(s)
* dfsf() Dummy fsf routine for non-tape
* devices..
* fsf() Forwardspace 'n' tape/file mark(s)
* rew() Rewinds the output device
* tape() Determine if device is tape or not
* tape_mark() Determines if a dummy tape mark
* was detected
* weof() Write an eof on output device
* (eof === a tape mark)
*
*
* Usage:
*
* n/a
*
* Compile:
*
* cc -O -c odm.c <- For Ultrix-32/32m
*
* cc CFLAGS=-DU11-O odm.c <- For Ultrix-11
*
*
* Modification history:
* ~~~~~~~~~~~~~~~~~~~~
*
* revision comments
* -------- -----------------------------------------------
* 01.0 09-Apr-85 Ray Glaser
* Create orginal version.
*
*/
/* */
/*
* -> Defintions required of / for this routine
*/
#define ODMC /* Flag our compile so that our routines are not declared
* external by the include file "ltfefs.h". */
/*
* -> Local includes
*/
#include "ltfdefs.h" /* Common GLOBAL definitions */
/*
* -> Module GLOBALS
*/
struct mtop Mtop; /* Mag tape operation ioctl structure */
/* */
/*
*
* Function:
*
* ceot
*
* Function Description:
*
* Check if end of tape encountered when receive errno
* from a read or write = -1.
*
* Arguments:
*
* none
*
* Return values:
*
* none
*
* Side Effects:
*
* If eot is encountered, an error message is output
* to stderr & the routine exits back to system control.
* If not eot, exits anyways due to read or write error.
*/
ceot()
{
/*
* -> Local includes
*/
struct mtget Mtstat; /* ioctl status structure */
if (Tape) {
if (ioctl(fileno(Magtfp), MTIOCGET, &Mtstat) < 0) {
PERROR "\n%s: %s %s\n", Progname, CANTCGET, Magtdev);
perror(Magtdev);
exit(FAIL);
}
else
if (Mtstat.mt_softstat & MT_EOT) {
PERROR "\n%s: %s %s\n", Progname, ERREOT, Magtdev);
perror(Magtdev);
exit(FAIL);
}
}
exit(FAIL);
}/*E ceot() */
/* */
/*
*
* Function:
*
* bsf
*
* Function Description:
*
* Backspace the output device 'n' file mark(s).
*
* Arguments:
*
* int n Number of tape/file mark(s) to backspace.
*
* Return values:
*
* none
*
* Side Effects:
*
* If the device cannot be backspaced,
* an error message is output to stderr &
* the routine exits back to system control.
*/
bsf(n)
int n;
{
if (!Tape) return;
Mtop.mt_count = n;
Mtop.mt_op = MTBSF;
if (ioctl(fileno(Magtfp), MTIOCTOP, &Mtop) < 0) {
PERROR "\n%s: %s %s\n", Progname, CANTBSF, Magtdev);
perror(Magtdev);
exit(FAIL);
}
}/*E bsf() */
/* */
/*
*
* Function:
*
* dfsf
*
* Function Description:
*
* This function "dummies" the Forward Space File operation
* for non-tape devices by reading thru the input data until
* it finds an LTF "dummy" tape mark.
*
* Arguments:
*
* none
*
* Return values:
*
* none
*
* Side Effects:
*
* If an error is encountered while trying to find the
* dummy tape mark, an message is output to stderr and
* the function exits to system control.
*/
dfsf()
{
FOREVER {
nottm:
if ((read(fileno(Magtfp), Dummy, BUFSIZE))<=0) {
PERROR "\n%s: %s %s\n", Progname, CANTFSF, Magtdev);
perror(Magtdev);
exit(FAIL);
}
if (!tape_mark(Dummy))
goto nottm;
else return;
}/*E FOREVER */
}/*E dfsf();
/* */
/*
*
* Function:
*
* fsf
*
* Function Description:
*
* Forward space the output device 'n' file/tape mark(s).
*
* Arguments:
*
* int n Desired number of tape/file marks to
* be forward spaced.
*
* Return values:
*
* int value The number of actual tape/file marks
* skipped is returned.
*
* Side Effects:
*
* If the device cannot be forward-spaced,
* an error message is output to stderr &
* the routine exits back to system control.
*
* It may be necessary to back-space, in which case the
* bsf() routine will be called and it may push out an
* error message of its own.
*/
fsf(n)
int n;
{
/*------*\
Code
\*------*/
Mtop.mt_count = 1;
Mtop.mt_op = MTFSF;
if (!Tape) {
for (i=0; i != n; i++) {
dfsf();
}
return(i);
}
for (i = 0; i != n; i++) {
if (ioctl(fileno(Magtfp), MTIOCTOP, &Mtop) < 0) {
PERROR "\n%s: %s %s\n", Progname, CANTFSF, Magtdev);
perror(Magtdev);
exit(FAIL);
}
}/*E for i = 0; i != n; i++ */
}/*E fsf() */
/* */
/*
*
* Function:
*
* rew
*
* Function Description:
*
* Rewinds the output device.
*
* Arguments:
*
* none
*
* Return values:
*
* none
*
*
* Side Effects:
*
* If the device cannot be opened for reading/writing,
* or the rewind fails, an error message is output to
* stderr & the routine exits back to system control.
*/
rew(n)
int n;
{
/*------*\
Code
\*------*/
if (!Tape)
if (Func == CREATE)
return;
if (n)
if (fclose(Magtfp) < 0) {
PERROR "\n%s: %s %s\n\n", Progname, CANTCLS, Magtdev);
perror(Magtdev);
exit(FAIL);
}
if (!(Magtfp = fopen(Magtdev, "r"))) {
PERROR "\n%s: %s %s\n\n", Progname, CANTOPEN, Magtdev);
perror(Magtdev);
exit(FAIL);
}
if (!Tape)
return;
Mtop.mt_op = MTREW;
Mtop.mt_count = 1;
if (ioctl( fileno(Magtfp), MTIOCTOP, &Mtop) < 0) {
PERROR "\n%s: %s %s\n", Progname, CANTREW, Magtdev);
perror(Magtdev);
exit(FAIL);
}
if (Func == CREATE)
if (fclose(Magtfp) < 0) {
PERROR "\n%s: %s %s\n\n", Progname, CANTCLS, Magtdev);
perror(Magtdev);
exit(FAIL);
}
}/*E rew() */
/* */
/*
*
* Function:
*
* tape
*
* Function Description:
*
* This function determines if the given device is,
* or is NOT a mag tape device.
*
* Arguments:
*
* char *special Pointer to the special device name
*
*
* Return values:
*
* TRUE -or- FALSE
*
* Side Effects:
*
* none
*/
tape(special)
char *special;
{
struct mtget Mtstat; /* ioctl status structure */
if (!(Magtfp = fopen(special, "r"))) {
Blocksize = BUFSIZE;
return(FALSE);
}
if (ioctl(fileno(Magtfp), MTIOCGET, &Mtstat) < 0) {
switch(errno) {
case ETPL:
case ETOL:
case ETWL:
case ETO:
break;
default:
fclose(Magtfp);
Blocksize = BUFSIZE;
return(FALSE);
}
}
fclose(Magtfp);
return(TRUE);
}/* tape */
/* */
/*
*
* Function:
*
* tape_mark
*
* Function Description:
*
* This function tests to see if the buffer pointed to
* on input contains a dummy TAPE_MARK used when
* processing non-tape devices.
*
* Arguments:
*
* char *bp Address of the buffer to test.
*
* Return values:
*
* Returns TRUE or FALSE - states whether or not the
* buffer contained a dummy tape mark.
*
* Side Effects:
*
* none
*/
tape_mark(bp)
char *bp;
{
/*
* If this is one of our dummy tape marks,
* the first chctr should be a control-s.
*/
if (*bp != TM)
return(FALSE);
else {
/*
* The next 'n' characters should read
* TAPE_MARK
*/
int i,j;
for (++bp,i=1,j=0; j<9; bp++,i++,j++)
if (*bp != Tape_Mark[j])
return(FALSE);
/*
* The remaining bytes should all be
* control-s characters.
*/
for (; i<BUFSIZE; i++,bp++)
if (*bp != TM)
return(FALSE);
}
/*
* If we got this far, we must have seen
* one of our dummy tape marks.
*/
return(TRUE);
}/*E tape_mark() */
/* */
/*
*
* Function:
*
* weof
*
* Function Description:
*
* Writes an eof (End-Of-File) on the output device
*
* Arguments:
*
* none
*
* Return values:
*
* none
*
* Side Effects:
*
* If an error is encountered writing the EOF,
* an error message is written to stderr &
* the routine exits to system control.
*/
weof()
{
if (!Tape) {
int i,j;
/* Write a dummy tape mark on out device so that
* input functions can.
*/
Dummy[0] = TM;
for (i=1,j=0; j<9; i++,j++)
Dummy[i] = Tape_Mark[j];
for ( ; i<=BUFSIZE; i++)
Dummy[i] = TM;
if ((write(fileno(Magtfp), Dummy, BUFSIZE))<=0)
goto weoferr;
/* Clear the buffer so that if read back our
* own image, we won't see ourselves as
* a pesudo tape mark.
*/
for (i=0; i <= BUFSIZE; i++)
Dummy[i] = Spaces[i];
return;
}/*E if !Tape */
/* For REAL tape devices..
*/
Mtop.mt_count = 1;
Mtop.mt_op = MTWEOF;
if (ioctl(fileno(Magtfp), MTIOCTOP, &Mtop) < 0) {
weoferr:
PERROR "\n%s: %s %s\n", Progname, CANTWEOF, Magtdev);
perror(Magtdev);
ceot();
}
}/*E weof() */
/**\\**\\**\\**\\**\\** EOM odm.c **\\**\\**\\**\\**\\*/
/**\\**\\**\\**\\**\\** EOM odm.c **\\**\\**\\**\\**\\*/