2.9BSD/usr/src/lib/libI77/endfile.c

/*
char id_endfile[] = "@(#)endfile.c	1.7";
 *
 * endfile
 */

#include "fio.h"

static char	endf[]	= "endfile";
extern	char	*tmplate;

f_end (a)
alist	*a;
{
	unit	*b;

	lfname = NULL;
	elist = NO;
	errflag = a->aerr;
	lunit = a->aunit;
	if (not_legal(lunit))
		err (errflag, F_ERUNIT, endf)
	b = &units[lunit];
	if (!b->ufd)
		err (errflag, F_ERNOPEN, endf)
	if (b->uend)
		return(0);
	lfname = b->ufnm;
	b->uend = YES;
	return ( t_runc (b, errflag, endf) );
}

t_runc (b, flag, str)
unit	*b;
ioflag	flag;
char	*str;
{
	char buf[128],nm[16];
	FILE *tmp;
	int n,m;
	long loc,len;
	fflush (b->ufd);
	if(b->url || !b->useek || !b->ufnm)
		return (OK);	/* don't truncate direct access files, etc. */
	if(b->uwrt && ! nowreading(b))
		err(errflag, errno, str);
	loc = ftell (b->ufd);
	fseek(b->ufd,0L,2);
	len = ftell (b->ufd);
	if (loc>=len)
		return(OK);
	strcpy(nm,tmplate);
	mktemp(nm);
	if(!(tmp=fopen(nm,"w"))) err(flag,errno,str);
	fseek(b->ufd,0L,0);
	while (loc)
	{
		n=fread(buf, 1, loc > sizeof(buf)?sizeof(buf):(int)loc, b->ufd);
		loc -= n;
		fwrite(buf,1,n,tmp);
	}
	fflush(tmp);
	for(n=0;n<10;n++)
	{
		if((m=fork())==-1) continue;
		else if(m==0)
		{
			execl("/bin/cp","cp",nm,b->ufnm,0);
			execl("/usr/bin/cp","cp",nm,b->ufnm,0);
			fatal(F_ERSYS,"no cp for trunc");
		}
		wait(&m);
		if(m) err(flag,F_ERTRUNC,str);
		fclose(tmp);
		unlink(nm);
		return(OK);
	}
	err(flag,F_ERTRUNC,str);
}