files.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 941 行 · 第 1/2 页

{
	TIMETYPE date = 0L;

	if(openarch(archname) == -1)
		return(0L);
	if(flag)
		date = entryscan(am);	/* fatals if cannot find entry */
	else
		date = afilescan(am);
	clarch();
	return(date);
}

TIMETYPE
afilescan(name)		/* return date for named archive member file */
char *name;
{
	int	len = strlen(name);
	long	ptr;

	if (fseek(arfd, first_ar_mem, 0) != 0)
	{
	seek_error:;
		fatal1("Seek error on archive file %s", archname);
	}
	/*
	* Hunt for the named file in each different type of
	* archive format.
	*/
	switch (ar_type)
	{
	case ARpdp:
		for (;;)
		{
			if (fread((char *)&ar_pdp,
				sizeof(ar_pdp), 1, arfd) != 1)
			{
				if (feof(arfd))
					return (0L);
				break;
			}
			if (equaln(ar_pdp.ar_name, name, len))
				return (ar_pdp.ar_date);
			ptr = ar_pdp.ar_size;
			ptr += (ptr & 01);
			if (fseek(arfd, ptr, 1) != 0)
				goto seek_error;
		}
		break;
#ifndef pdp11
	case AR5:
		for (;;)
		{
			if (fread((char *)&arf_5, sizeof(arf_5), 1, arfd) != 1)
			{
				if (feof(arfd))
					return (0L);
				break;
			}
			if (equaln(arf_5.arf_name, name, len))
				return (sgetl(arf_5.arf_date));
			ptr = sgetl(arf_5.arf_size);
			ptr += (ptr & 01);
			if (fseek(arfd, ptr, 1) != 0)
				goto seek_error;
		}
		break;
	case ARport:
		for (;;)
		{
			if (fread((char *)&ar_port, sizeof(ar_port), 1,
				arfd) != 1 || !equaln(ar_port.ar_fmag,
				ARFportMAG, sizeof(ar_port.ar_fmag)))
			{
				if (feof(arfd))
					return (0L);
				break;
			}
			if (equaln(ar_port.ar_name, name, len))
			{
				long date;

				if (sscanf(ar_port.ar_date, "%ld", &date) != 1)
				{
					fatal1("Bad date field for %.14s in %s",
						name, archname);
				}
				return (date);
			}
			if (sscanf(ar_port.ar_size, "%ld", &ptr) != 1)
			{
				fatal1("Bad size field for %.14s in archive %s",
					name, archname);
			}
			ptr += (ptr & 01);
			if (fseek(arfd, ptr, 1) != 0)
				goto seek_error;
		}
		break;
#endif
	}
	/*
	* Only here if fread() [or equaln()] failed and not at EOF
	*/
	fatal1("Read error on archive %s", archname);
	/*NOTREACHED*/
#if 0
	long date;
	long nsyms;
	long ptr;

	nsyms = sgetl(head.ar_syms);
	if(fseek(arfd, (long)( nsyms*sizeof(symbol)+sizeof(head) ), 0) == -1)
		fatal("Seek error on archive file %s", archname);
	for(;;)
	{
		if(fread(&fhead, sizeof(fhead), 1, arfd) != 1)
			if(feof(arfd))
				break;
			else
				fatal("Read error on archive %s", archname);
		if(equaln(fhead.arf_name, name, 14))
		{
			date = sgetl(fhead.arf_date);
			return(date);
		}
		ptr = sgetl(fhead.arf_size);
		ptr = (ptr+1)&(~1);
		fseek(arfd, ptr, 1);
	}
	return( 0L );
#endif
}

TIMETYPE
entryscan(name)		/* return date of member containing global var named */
char *name;
{
	/*
	* Hunt through each different archive format for the named
	* symbol.  Note that the old archive format does not support
	* this convention since there is no symbol directory to
	* scan through for all defined global variables.
	*/
	if (ar_type == ARpdp)
		return (pdpentrys(name));
	if (sym_begin == 0L || num_symbols == 0L)
	{
	no_such_sym:;
		fatal1("Cannot find symbol %s in archive %s", name, archname);
	}
	if (fseek(arfd, sym_begin, 0) != 0)
	{
	seek_error:;
		fatal1("Seek error on archive file %s", archname);
	}
#ifndef pdp11
	if (ar_type == AR5)
	{
		register int i;
		int len = strlen(name);

		if (len > 8)
			len = 8;
		for (i = 0; i < num_symbols; i++)
		{
			if (fread((char *)&ars_5, sizeof(ars_5), 1, arfd) != 1)
			{
			read_error:;
				fatal1("Read error on archive %s", archname);
			}
			if (equaln(ars_5.sym_name, name, len))
			{
				if (fseek(arfd, sgetl(ars_5.sym_ptr), 0) != 0)
					goto seek_error;
				if (fread((char *)&arf_5,
					sizeof(arf_5), 1, arfd) != 1)
				{
					goto read_error;
				}
				return (sgetl(arf_5.arf_date));
			}
		}
	}
	else	/* ar_type == ARport */
	{
		register int strtablen;
		register char *offs;	/* offsets table */
		register char *syms;	/* string table */
		register char *strend;	/* end of string table */
		register char *strbeg;

		/*
		* Format of the symbol directory for this format is
		* as follows:	[sputl()d number_of_symbols]
		*		[sputl()d first_symbol_offset]
		*			...
		*		[sputl()d number_of_symbols'_offset]
		*		[null_terminated_string_table_of_symbols]
		*/
		if ((offs = calloc(num_symbols,sizeof(long))) == NULL)
		{
			fatal1("Cannot calloc offsets table for archive %s",
				archname);
		}
		if (fread(offs, sizeof(long), num_symbols, arfd) != num_symbols)
			goto read_error;
		strtablen = sym_size - ((num_symbols + 1) * sizeof(long));
		if ((syms = calloc(1,strtablen)) == NULL)
		{
			fatal1("Cannot calloc string table for archive %s",
				archname);
		}
		if (fread(syms, sizeof(char), strtablen, arfd) != strtablen)
			goto read_error;
		strend = &syms[strtablen];
		strbeg = syms;
		while (syms < strend)
		{
			if (equal(syms, name))
			{
				long ptr, date;

				ptr = sgetl(offs);
				if (fseek(arfd, ptr, 0) != 0)
					goto seek_error;
				if (fread((char *)&ar_port, sizeof(ar_port), 1,
					arfd) != 1 || !equaln(ar_port.ar_fmag,
					ARFportMAG, sizeof(ar_port.ar_fmag)))
				{
					goto read_error;
				}
				if (sscanf(ar_port.ar_date, "%ld", &date) != 1)
				{
					fatal1("Bad date for %.14s, archive %s",
						ar_port.ar_name, archname);
				}
				free(strbeg);
				return (date);
			}
			syms += strlen(syms) + 1;
			offs += sizeof(long);
		}
		free(strbeg);
	}
#endif
	goto no_such_sym;
#if 0
	register int i;
	long date;
	long ptr;
	long nsyms;

	nsyms = sgetl(head.ar_syms);
	for(i = 0; i < nsyms; i++)
	{
		if(fread(&symbol, sizeof(symbol), 1, arfd) != 1)
badread:
			fatal("Read error on archive %s", archname);
		if(equaln(symbol.sym_name, name, 8))
		{
			ptr = sgetl(symbol.sym_ptr);
			if(fseek(arfd, ptr, 0) == -1)
				fatal("Seek error on archive file %s",archname);
			if(fread(fhead, sizeof(fhead), 1, arfd) != 1)
				goto badread;
			date = sgetl(fhead.arf_date);
			return(date);
		}
	}
	fatal("Cannot find symbol %s in archive %s", name, archname);
#endif
}

TIMETYPE
pdpentrys(name)
	char *name;
{
	long	skip;
	long	last;
	int	len;
	register int i;

#ifndef pdp11
	fatal("Cannot do global variable search in pdp11 or old object file.");
#endif
	len = strlen(name);
	if (len > 8)
		len = 8;
	/*
	* Look through archive, an object file entry at a time.  For each
	* object file, jump to its symbol table and check each external
	* symbol for a match.  If found, return the date of the module
	* containing the symbol.
	*/
	if (fseek(arfd, sizeof(short), 0) != 0)
	{
	seek_error:;
		fatal1("Cannot seek on archive file %s", archname);
	}
	while (fread((char *)&ar_pdp, sizeof(ar_pdp), 1, arfd) == 1)
	{
		last = ftell(arfd);
		if (ar_pdp.ar_size < sizeof(arobj_pdp) ||
			fread((char *)&arobj_pdp, sizeof(arobj_pdp), 1, arfd)
			!= 1 ||
			(arobj_pdp.a_magic != 0401 &&	/* A_MAGIC0 */
			arobj_pdp.a_magic != 0407 &&	/* A_MAGIC1 */
			arobj_pdp.a_magic != 0410 &&	/* A_MAGIC2 */
			arobj_pdp.a_magic != 0411 &&	/* A_MAGIC3 */
			arobj_pdp.a_magic != 0405 &&	/* A_MAGIC4 */
			arobj_pdp.a_magic != 0437)) 	/* A_MAGIC5 */
		{
			fatal1("%s is not an object module", ar_pdp.ar_name);
		}
		skip = arobj_pdp.a_text + arobj_pdp.a_data;
		if (!arobj_pdp.a_flag)
			skip *= 2;
		if (skip >= ar_pdp.ar_size || fseek(arfd, skip, 1) != 0)
			goto seek_error;
		skip = ar_pdp.ar_size;
		skip += (skip & 01) + last;
		i = (arobj_pdp.a_syms / sizeof(ars_pdp)) + 1;
		while (--i > 0)		/* look through symbol table */
		{
			if (fread((char *)&ars_pdp, sizeof(ars_pdp), 1, arfd)
				!= 1)
			{
				fatal1("Read error on archive %s", archname);
			}
			if ((ars_pdp.n_type & 040)	/* N_EXT for pdp11 */
				&& equaln(ars_pdp.n_name, name, len))
			{
				(void)strncpy(archmem, ar_pdp.ar_name, 14);
				archmem[14] = '\0';
				return (ar_pdp.ar_date);
			}
		}
		if (fseek(arfd, skip, 0) != 0)
			goto seek_error;
	}
	return (0L);
}


openarch(f)
register CHARSTAR f;
{
	unsigned short	mag_pdp;		/* old archive format */
	char		mag_5[SAR5MAG];		/* 5.0 archive format */
	char		mag_port[SARportMAG];	/* port (6.0) archive format */

	arfd = fopen(f, "r");
	if(arfd == NULL)
		return(-1);
	/*
	* More code for three archive formats.  Read in just enough to
	* distinguish the three types and set ar_type.  Then if it is
	* one of the newer archive formats, gather more info.
	*/
	if (fread((char *)&mag_pdp, sizeof(mag_pdp), 1, arfd) != 1)
		return (-1);
	if (mag_pdp == (unsigned short)ARpdpMAG)
	{
		ar_type = ARpdp;
		first_ar_mem = ftell(arfd);
		sym_begin = num_symbols = sym_size = 0L;
		return (0);
	}
	if (fseek(arfd, 0L, 0) != 0 || fread(mag_5, SAR5MAG, 1, arfd) != 1)
		return (-1);
	if (equaln(mag_5, AR5MAG, SAR5MAG))
	{
		ar_type = AR5;
		/*
		* Must read in header to set necessary info
		*/
		if (fseek(arfd, 0L, 0) != 0 ||
			fread((char *)&arh_5, sizeof(arh_5), 1, arfd) != 1)
		{
			return (-1);
		}
#ifdef pdp11
		fatal1("Cannot handle 5.0 archive format for %s", archname);
		/*NOTREACHED*/
#else
		sym_begin = ftell(arfd);
		num_symbols = sgetl(arh_5.ar_syms);
		first_ar_mem = sym_begin + sizeof(ars_5) * num_symbols;
		sym_size = 0L;
		return (0);
#endif
	}
	if (fseek(arfd, 0L, 0) != 0 ||
		fread(mag_port, SARportMAG, 1, arfd) != 1)
	{
		return (-1);
	}
	if (equaln(mag_port, ARportMAG, SARportMAG))
	{
		ar_type = ARport;
		/*
		* Must read in first member header to find out
		* if there is a symbol directory
		*/
		if (fread((char *)&ar_port, sizeof(ar_port), 1, arfd) != 1 ||
			!equaln(ARFportMAG, ar_port.ar_fmag,
			sizeof(ar_port.ar_fmag)))
		{
			return (-1);
		}
#ifdef pdp11
		fatal1("Cannot handle portable archive format for %s",
			archname);
		/*NOTREACHED*/
#else
		if (ar_port.ar_name[0] == '/')
		{
			char s[4];

			if (sscanf(ar_port.ar_size, "%ld", &sym_size) != 1)
				return (-1);
			sym_size += (sym_size & 01);	/* round up */
			if (fread(s, sizeof(s), 1, arfd) != 1)
				return (-1);
			num_symbols = sgetl(s);
			sym_begin = ftell(arfd);
			first_ar_mem = sym_begin + sym_size - sizeof(s);
		}
		else	/* there is no symbol directory */
		{
			sym_size = num_symbols = sym_begin = 0L;
			first_ar_mem = ftell(arfd) - sizeof(ar_port);
		}
		return (0);
#endif
	}
	fatal1("%s is not an archive", f);
	/*NOTREACHED*/
#if 0
	if(fread(&head, sizeof(head), 1, arfd) != 1)
		return(-1);
	if(!equaln(head.ar_magic, ARMAG, 4))
		fatal1("%s is not an archive", f);
	return(0);
#endif
}

clarch()
{
	if(arfd != NULL)
		fclose(arfd);
}

/*
 *	Used when unlinking files. If file cannot be stat'ed or it is
 *	a directory, then do not remove it.
 */
isdir(p)
char *p;
{
	struct stat statbuf;

	if(stat(p, &statbuf) == -1)
		return(1);		/* no stat, no remove */
	if((statbuf.st_mode&S_IFMT) == S_IFDIR)
		return(1);
	return(0);
}