cde/programs/dtksh/ksh93/src/lib/libcmd/revlib.c

   1 /*
   2  * CDE - Common Desktop Environment
   3  *
   4  * Copyright (c) 1993-2012, The Open Group. All rights reserved.
   5  *
   6  * These libraries and programs are free software; you can
   7  * redistribute them and/or modify them under the terms of the GNU
   8  * Lesser General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * These libraries and programs are distributed in the hope that
  13  * they will be useful, but WITHOUT ANY WARRANTY; without even the
  14  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  15  * PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with these librararies and programs; if not, write
  20  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  21  * Floor, Boston, MA 02110-1301 USA
  22  */
  23 /* $XConsortium: revlib.c /main/3 1995/11/01 19:07:43 rswiston $ */
  24 /***************************************************************
  25 *                                                              *
  26 *                      AT&T - PROPRIETARY                      *
  27 *                                                              *
  28 *         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
  29 *                          AT&T CORP.                          *
  30 *                                                              *
  31 *                Copyright (c) 1995 AT&T Corp.                 *
  32 *                     All Rights Reserved                      *
  33 *                                                              *
  34 *           This software is licensed by AT&T Corp.            *
  35 *       under the terms and conditions of the license in       *
  36 *       http://www.research.att.com/orgs/ssr/book/reuse        *
  37 *                                                              *
  38 *               This software was created by the               *
  39 *           Software Engineering Research Department           *
  40 *                    AT&T Bell Laboratories                    *
  41 *                                                              *
  42 *               For further information contact                *
  43 *                     gsf@research.att.com                     *
  44 *                                                              *
  45 ***************************************************************/
  46
  47 /* : : generated by proto : : */
  48
  49 #if !defined(__PROTO__)
  50 #if defined(__STDC__) || defined(__cplusplus) || defined(_proto) || defined(c_plusplus)
  51 #if defined(__cplusplus)
  52 #define __MANGLE__      "C"
  53 #else
  54 #define __MANGLE__
  55 #endif
  56 #define __STDARG__
  57 #define __PROTO__(x)    x
  58 #define __OTORP__(x)
  59 #define __PARAM__(n,o)  n
  60 #if !defined(__STDC__) && !defined(__cplusplus)
  61 #if !defined(c_plusplus)
  62 #define const
  63 #endif
  64 #define signed
  65 #define void            int
  66 #define volatile
  67 #define __V_            char
  68 #else
  69 #define __V_            void
  70 #endif
  71 #else
  72 #define __PROTO__(x)    ()
  73 #define __OTORP__(x)    x
  74 #define __PARAM__(n,o)  o
  75 #define __MANGLE__
  76 #define __V_            char
  77 #define const
  78 #define signed
  79 #define void            int
  80 #define volatile
  81 #endif
  82 #if defined(__cplusplus) || defined(c_plusplus)
  83 #define __VARARG__      ...
  84 #else
  85 #define __VARARG__
  86 #endif
  87 #if defined(__STDARG__)
  88 #define __VA_START__(p,a)       va_start(p,a)
  89 #else
  90 #define __VA_START__(p,a)       va_start(p)
  91 #endif
  92 #endif
  93 #include        <cmdlib.h>
  94
  95 #define BUFSIZE                 SF_BUFSIZE
  96 #define rounddown(n,size)       (((n)-1)&~((size)-1))
  97
  98 /*
  99  * copy the lines starting at offset <start> from in <in> to <out>
 100  * in reverse order
 101  */
 102 int rev_line __PARAM__((Sfio_t *in, Sfio_t *out, off_t start), (in, out, start)) __OTORP__(Sfio_t *in; Sfio_t *out; off_t start;){
 103         register char *cp, *cpold;
 104         register int n, nleft=0;
 105         char buff[BUFSIZE];
 106         off_t offset;
 107         if(sfseek(in,(off_t)0,SEEK_CUR) < 0)
 108         {
 109                 Sfio_t *tmp = sftmp(4*SF_BUFSIZE);
 110                 if(!tmp)
 111                         return(-1);
 112                 if(start>0)
 113                         sfmove(in, (Sfio_t*)0, (long)start, -1);
 114                 if(sfmove(in, tmp, SF_UNBOUND, -1) < 0)
 115                         return(-1);
 116                 in = tmp;
 117                 start=0;
 118         }
 119         if((offset = sfseek(in,(off_t)0,SEEK_END)) <= start)
 120                 return(0);
 121         offset = rounddown(offset,BUFSIZE);
 122         while(1)
 123         {
 124                 n = BUFSIZE;
 125                 if(offset < start)
 126                 {
 127                         n -= (start-offset);
 128                         offset = start;
 129                 }
 130                 sfseek(in, offset, SEEK_SET);
 131                 if((n=sfread(in, buff, n)) <=0)
 132                         break;
 133                 cp = buff+n;
 134                 n = *buff;
 135                 *buff = '\n';
 136                 while(1)
 137                 {
 138                         cpold = cp;
 139                         if(nleft==0)
 140                                 cp--;
 141                         if(cp==buff)
 142                         {
 143                                 nleft= 1;
 144                                 break;
 145                         }
 146                         while(*--cp != '\n');
 147                         if(cp==buff && n!='\n')
 148                         {
 149                                 *cp = n;
 150                                 nleft += cpold-cp;
 151                                 break;
 152                         }
 153                         else
 154                                 cp++;
 155                         if(sfwrite(out,cp,cpold-cp) < 0)
 156                                 return(-1);
 157                         if(nleft)
 158                         {
 159                                 if(nleft==1)
 160                                         sfputc(out,'\n');
 161                                 else if(sfmove(in,out,nleft,-1) < 0)
 162                                         return(-1);
 163                                 nleft = 0;
 164                         }
 165                 }
 166                 if(offset <= start)
 167                         break;
 168                 offset -= BUFSIZE;
 169         }
 170         if(nleft)
 171         {
 172                 sfseek(in, start, SEEK_SET);
 173                 if(sfmove(in,out,nleft,-1) < 0)
 174                         return(-1);
 175         }
 176         return(0);
 177 }