da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/***********************************************************************
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* This software is part of the ast package *
3e14f97f673e8a630f076077de35afdd43dc1587Roger A. Faulkner* Copyright (c) 1992-2010 AT&T Intellectual Property *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* and is licensed under the *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Common Public License, Version 1.0 *
7c2fbfb345896881c631598ee3852ce9ce33fb07April Chin* by AT&T Intellectual Property *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* A copy of the License is available at *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* http://www.opensource.org/licenses/cpl1.0.txt *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Information and Software Systems Research *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* AT&T Research *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Florham Park NJ *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* Glenn Fowler <gsf@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* David Korn <dgk@research.att.com> *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin* *
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin***********************************************************************/
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#pragma prototyped
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * common support for tail and rev
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <cmd.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#include <rev.h>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define BUFSIZE SF_BUFSIZE
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin#define rounddown(n,size) (((n)-1)&~((size)-1))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin/*
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * copy the lines starting at offset <start> from in <in> to <out>
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin * in reverse order
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin */
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chinint rev_line(Sfio_t *in, Sfio_t *out, off_t start)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin{
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin register char *cp, *cpold;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin register int n, nleft=0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin char buff[BUFSIZE];
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin off_t offset;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfseek(in,(off_t)0,SEEK_CUR) < 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin Sfio_t *tmp = sftmp(4*SF_BUFSIZE);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(!tmp)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(start>0 && sfmove(in, (Sfio_t*)0, start, -1) != start)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfmove(in, tmp, SF_UNBOUND, -1) < 0 || !sfeof(in) || sferror(tmp))
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin in = tmp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin start=0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if((offset = sfseek(in,(off_t)0,SEEK_END)) <= start)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin offset = rounddown(offset,BUFSIZE);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin while(1)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n = BUFSIZE;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(offset < start)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n -= (start-offset);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin offset = start;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin sfseek(in, offset, SEEK_SET);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if((n=sfread(in, buff, n)) <=0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin cp = buff+n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin n = *buff;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *buff = '\n';
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin while(1)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin cpold = cp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(nleft==0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin cp--;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(cp==buff)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin nleft= 1;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin while(*--cp != '\n');
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(cp==buff && n!='\n')
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin *cp = n;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin nleft += cpold-cp;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin cp++;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfwrite(out,cp,cpold-cp) < 0)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(nleft)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(nleft==1)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin sfputc(out,'\n');
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin else if(sfmove(in,out,nleft,-1) != nleft)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin nleft = 0;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(offset <= start)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin break;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin offset -= BUFSIZE;
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(nleft)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin {
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin sfseek(in, start, SEEK_SET);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin if(sfmove(in,out,nleft,-1) != nleft)
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(-1);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin }
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin return(0);
da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968chin}