Open64: osprey/libI77/rewind.c Source File

00001 /*
00002 
00003   Copyright (C) 2000, 2001 Silicon Graphics, Inc.  All Rights Reserved.
00004 
00005   This program is free software; you can redistribute it and/or modify it
00006   under the terms of version 2.1 of the GNU Lesser General Public License 
00007   as published by the Free Software Foundation.
00008 
00009   This program is distributed in the hope that it would be useful, but
00010   WITHOUT ANY WARRANTY; without even the implied warranty of
00011   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
00012 
00013   Further, this software is distributed without any warranty that it is
00014   free of the rightful claim of any third person regarding infringement 
00015   or the like.  Any license provided herein, whether implied or 
00016   otherwise, applies only to this software file.  Patent licenses, if
00017   any, provided herein do not apply to combinations of this program with 
00018   other software, or any other product whatsoever.  
00019 
00020   You should have received a copy of the GNU Lesser General Public 
00021   License along with this program; if not, write the Free Software 
00022   Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
00023   USA.
00024 
00025   Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
00026   Mountain View, CA 94043, or:
00027 
00028   http://www.sgi.com
00029 
00030   For further information regarding this notice, see:
00031 
00032   http://oss.sgi.com/projects/GenInfo/NoticeExplan
00033 
00034 */
00035 
00036 
00037 /* $Header: /proj/osprey/CVS/open64/osprey1.0/libI77/rewind.c,v 1.1.1.1 2005/10/21 19:00:00 marcel Exp $ */
00038 /*  3.0 SID # 1.2 */
00039 #include <cmplrs/fio.h>
00040 #include <mutex.h>
00041 #include "fmt.h"
00042 #include "iomode.h"
00043 #include "vmsflags.h"
00044 #include "err.h"
00045 #include "close.h"
00046 #include "unistd.h"
00047 #include "util.h"
00048 #include "bcompat.h"
00049 
00050 #define ASSOCV  12
00051 
00052 #define get_alist64(p_dst, p_src) ((p_dst)->aerr = (p_src)->aerr, (p_dst)->aunit = (p_src)->aunit)
00053 
00054 static int
00055 f_rew_com (alist *a, int lock)
00056 {
00057    unit           *ftnunit;
00058   
00059    if ((ftnunit = find_luno (a->aunit)) == NULL)
00060       return(0);
00061    while (lock && test_and_set( &ftnunit->lock_unit, 1L ))
00062        ;
00063 
00064    if (ftnunit->uacc == KEYED)
00065       errret(a->aerr, 164, "rewind");
00066 
00067    if (ftnunit->uconn <= 0) {
00068       ftnunit->lock_unit = 0;
00069       return (0);
00070    }
00071 
00072    if (!ftnunit->useek && !ftnunit->uistty)
00073       errret(a->aerr, 106, "rewind");
00074    ftnunit->uend = 0;
00075 
00076    /* Need to reset the associate variable to 1 if exists */
00077    if (ftnunit->uassocv)
00078       set_var (ftnunit->uassocv, ftnunit->umask, ASSOCV, (ftnll) 1);
00079 
00080    /* Rewind of a direct unformatted file. */
00081 
00082    if ((ftnunit->uacc == DIRECT) && (ftnunit->ufmt == 0)) {
00083       if (-1 == lseek ((int) ftnunit->ufd, 0, SEEK_SET)) {
00084    errret(a->aerr, 106, "rewind");
00085       }
00086       /* need to change the internal buffer position in fio_direct_io as well */
00087       _fio_set_seek((int) ftnunit->ufd,  (ftnll) 0, 0);
00088       ftnunit->uirec = 0;
00089       ftnunit->lock_unit = 0;
00090       return (1);
00091    }
00092 
00093 #ifdef I90
00094    /* Make sure these variables are zeroed out to allow record to be reread. */
00095    ftnunit->f77recpos = 0;
00096    ftnunit->f77recend = 0;
00097 #endif
00098 
00099    if (f77vms_flag_[VMS_EF]) {  /* rewind to the last endfile record
00100          * or beginning of file */
00101       char            buf[513];
00102       XINT64             y, x;
00103       int  i, n;
00104       char            ch;
00105 
00106       /*  If last operation was a WRITE, truncate the file and then make
00107       sure that the file mode is switched to READ so the the next 
00108       REWIND/BACKSPACE won't truncate the file again
00109       */
00110       if (ftnunit->uwrt & WR_OP) {
00111 #ifdef I90
00112    /* If in Fortran-90 nonadvancing mode, write endfile record (\n only). */
00113    if (ftnunit->f90sw == 1 && ftnunit->f90nadv == 1 ) {
00114        putc ('\n', ftnunit->ufd);
00115        ftnunit->f90nadv = 0;
00116    }
00117 #endif
00118    (void) t_runc (ftnunit, a->aerr);
00119    /* If the file is in write-only mode make sure that it is readable */
00120    if (f77nowreading(ftnunit))
00121       errret(a->aerr, 106, "rewind");
00122       }
00123       if (ftnunit->ufmt != 1) {
00124    if (ftell (ftnunit->ufd) == 0) {
00125             ftnunit->lock_unit = 0;
00126       return (0);   /* already at beginning of file */
00127    }
00128    if (fseek (ftnunit->ufd, (long) (-sizeof (int)), 1) < 0)
00129       errret(a->aerr, 106, "rewind");
00130    for (i = 0;; i++) {
00131       (void) fread ((char *) &n, sizeof (int), 1, ftnunit->ufd);
00132       if (n != 1 || i == 0) {
00133          if (fseek (ftnunit->ufd, (long) (-n - 3 * sizeof (int)), 1)) {
00134       rewind (ftnunit->ufd);
00135                   ftnunit->lock_unit = 0;
00136       return (0);
00137          }
00138       } else {
00139          if (fseek (ftnunit->ufd, -(sizeof (int) + 1), 1)) {
00140       rewind (ftnunit->ufd);
00141                   ftnunit->lock_unit = 0;
00142       return (0);
00143          }
00144          (void) fread ((char *) &ch, 1, 1, ftnunit->ufd);
00145          if (ch == '\032') {
00146       fseek (ftnunit->ufd, sizeof (int), 1);
00147                   ftnunit->lock_unit = 0;
00148       return (0);
00149          }
00150          fseek (ftnunit->ufd, -(2 * sizeof (int) + 1), 1);
00151       }
00152    }
00153       }
00154       y = x = FTELL (ftnunit->ufd) - 2; /* skip the last endfile
00155            * record */
00156       if (y < 0) {
00157     (void) fseek(ftnunit->ufd, 0L, 0);
00158           ftnunit->lock_unit = 0;
00159     return(0);
00160       }
00161       ch = '\0';
00162       for (;;) {
00163    if (x < sizeof (buf) - 1)
00164       x = 0;
00165    else
00166       x -= sizeof (buf) - 1;
00167    (void) FSEEK (ftnunit->ufd, x, 0);
00168    n = (int) fread (buf, 1, (int) (y - x), ftnunit->ufd);
00169    buf[n] = ch;
00170    for (i = n - 1; i >= 1; i--) {
00171       if (buf[i] != '\032' || buf[i + 1] != '\n')
00172          continue;
00173       (void) fseek (ftnunit->ufd, (long) (i + 2 - n), 1);
00174             ftnunit->lock_unit = 0;
00175       return (0);
00176    }
00177    if (x == 0) {
00178       (void) fseek (ftnunit->ufd, 0L, 0);
00179             ftnunit->lock_unit = 0;
00180       return (0);
00181    }
00182    y = x;
00183    ch = buf[0];
00184       }
00185    }
00186       /*  If last operation was a WRITE, truncate the file and then make
00187       sure that the file mode is switched to READ so the the next 
00188       REWIND/BACKSPACE won't truncate the file again
00189       */
00190    if (ftnunit->uwrt & WR_OP) {
00191 #ifdef I90
00192       /* If in Fortran-90 nonadvancing mode, write endfile record (\n only). */
00193       if (ftnunit->f90sw == 1 && ftnunit->f90nadv == 1 ) {
00194     putc ('\n', ftnunit->ufd);
00195     ftnunit->f90nadv = 0;
00196       }
00197 #endif
00198       (void) t_runc (ftnunit, a->aerr);
00199       /* If the file is in write-only mode make sure that it is readable */
00200       if (f77nowreading(ftnunit))
00201    errret(a->aerr, 106, "backspace");
00202    }
00203    rewind (ftnunit->ufd);
00204    ftnunit->lock_unit = 0;
00205    return (0);
00206 }
00207 
00208 int
00209 f_rew (alist *a)
00210 {
00211     return( f_rew_com( a, 0 ) );
00212 }
00213 
00214 int
00215 f_rew64_mp (alist *a)
00216 {
00217     return( f_rew_com( a, 1 ) );
00218 }
00219 
00220 #pragma weak f_rew64 = f_rew