749 lines
17 KiB
C
749 lines
17 KiB
C
/* Miscellaneous functions, not really specific to GNU tar.
|
||
|
||
Copyright (C) 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
|
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2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
|
||
|
||
This program is free software; you can redistribute it and/or modify it
|
||
under the terms of the GNU General Public License as published by the
|
||
Free Software Foundation; either version 3, or (at your option) any later
|
||
version.
|
||
|
||
This program is distributed in the hope that it will be useful, but
|
||
WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
|
||
Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License along
|
||
with this program; if not, write to the Free Software Foundation, Inc.,
|
||
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
|
||
|
||
#include <system.h>
|
||
#include <rmt.h>
|
||
#include "common.h"
|
||
#include <quotearg.h>
|
||
#include <save-cwd.h>
|
||
#include <xgetcwd.h>
|
||
#include <unlinkdir.h>
|
||
#include <utimens.h>
|
||
|
||
#if HAVE_STROPTS_H
|
||
# include <stropts.h>
|
||
#endif
|
||
#if HAVE_SYS_FILIO_H
|
||
# include <sys/filio.h>
|
||
#endif
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||
|
||
|
||
/* Handling strings. */
|
||
|
||
/* Assign STRING to a copy of VALUE if not zero, or to zero. If
|
||
STRING was nonzero, it is freed first. */
|
||
void
|
||
assign_string (char **string, const char *value)
|
||
{
|
||
if (*string)
|
||
free (*string);
|
||
*string = value ? xstrdup (value) : 0;
|
||
}
|
||
|
||
/* Allocate a copy of the string quoted as in C, and returns that. If
|
||
the string does not have to be quoted, it returns a null pointer.
|
||
The allocated copy should normally be freed with free() after the
|
||
caller is done with it.
|
||
|
||
This is used in one context only: generating the directory file in
|
||
incremental dumps. The quoted string is not intended for human
|
||
consumption; it is intended only for unquote_string. The quoting
|
||
is locale-independent, so that users needn't worry about locale
|
||
when reading directory files. This means that we can't use
|
||
quotearg, as quotearg is locale-dependent and is meant for human
|
||
consumption. */
|
||
char *
|
||
quote_copy_string (const char *string)
|
||
{
|
||
const char *source = string;
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||
char *destination = 0;
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||
char *buffer = 0;
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||
int copying = 0;
|
||
|
||
while (*source)
|
||
{
|
||
int character = *source++;
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||
|
||
switch (character)
|
||
{
|
||
case '\n': case '\\':
|
||
if (!copying)
|
||
{
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||
size_t length = (source - string) - 1;
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||
|
||
copying = 1;
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||
buffer = xmalloc (length + 2 + 2 * strlen (source) + 1);
|
||
memcpy (buffer, string, length);
|
||
destination = buffer + length;
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||
}
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*destination++ = '\\';
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||
*destination++ = character == '\\' ? '\\' : 'n';
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break;
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default:
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if (copying)
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*destination++ = character;
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break;
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||
}
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||
}
|
||
if (copying)
|
||
{
|
||
*destination = '\0';
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||
return buffer;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* Takes a quoted C string (like those produced by quote_copy_string)
|
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and turns it back into the un-quoted original. This is done in
|
||
place. Returns 0 only if the string was not properly quoted, but
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||
completes the unquoting anyway.
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||
|
||
This is used for reading the saved directory file in incremental
|
||
dumps. It is used for decoding old `N' records (demangling names).
|
||
But also, it is used for decoding file arguments, would they come
|
||
from the shell or a -T file, and for decoding the --exclude
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||
argument. */
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||
int
|
||
unquote_string (char *string)
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||
{
|
||
int result = 1;
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||
char *source = string;
|
||
char *destination = string;
|
||
|
||
/* Escape sequences other than \\ and \n are no longer generated by
|
||
quote_copy_string, but accept them for backwards compatibility,
|
||
and also because unquote_string is used for purposes other than
|
||
parsing the output of quote_copy_string. */
|
||
|
||
while (*source)
|
||
if (*source == '\\')
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||
switch (*++source)
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||
{
|
||
case '\\':
|
||
*destination++ = '\\';
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||
source++;
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break;
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||
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||
case 'a':
|
||
*destination++ = '\a';
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||
source++;
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||
break;
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||
|
||
case 'b':
|
||
*destination++ = '\b';
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||
source++;
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break;
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||
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||
case 'f':
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||
*destination++ = '\f';
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||
source++;
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||
break;
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||
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||
case 'n':
|
||
*destination++ = '\n';
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||
source++;
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||
break;
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||
|
||
case 'r':
|
||
*destination++ = '\r';
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||
source++;
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||
break;
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||
|
||
case 't':
|
||
*destination++ = '\t';
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||
source++;
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||
break;
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||
|
||
case 'v':
|
||
*destination++ = '\v';
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||
source++;
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||
break;
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||
|
||
case '?':
|
||
*destination++ = 0177;
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||
source++;
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||
break;
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||
|
||
case '0':
|
||
case '1':
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||
case '2':
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||
case '3':
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||
case '4':
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||
case '5':
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||
case '6':
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||
case '7':
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||
{
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||
int value = *source++ - '0';
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||
|
||
if (*source < '0' || *source > '7')
|
||
{
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||
*destination++ = value;
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||
break;
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||
}
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||
value = value * 8 + *source++ - '0';
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||
if (*source < '0' || *source > '7')
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||
{
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||
*destination++ = value;
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break;
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}
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value = value * 8 + *source++ - '0';
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||
*destination++ = value;
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break;
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||
}
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||
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||
default:
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result = 0;
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*destination++ = '\\';
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if (*source)
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*destination++ = *source++;
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break;
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||
}
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else if (source != destination)
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*destination++ = *source++;
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else
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source++, destination++;
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||
|
||
if (source != destination)
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||
*destination = '\0';
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||
return result;
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||
}
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||
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||
/* Handling numbers. */
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||
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||
/* Output fraction and trailing digits appropriate for a nanoseconds
|
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count equal to NS, but don't output unnecessary '.' or trailing
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||
zeros. */
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||
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||
void
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||
code_ns_fraction (int ns, char *p)
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||
{
|
||
if (ns == 0)
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||
*p = '\0';
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||
else
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||
{
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||
int i = 9;
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||
*p++ = '.';
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||
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||
while (ns % 10 == 0)
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||
{
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||
ns /= 10;
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||
i--;
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||
}
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||
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||
p[i] = '\0';
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||
for (;;)
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||
{
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||
p[--i] = '0' + ns % 10;
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||
if (i == 0)
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||
break;
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||
ns /= 10;
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||
}
|
||
}
|
||
}
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||
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||
char const *
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||
code_timespec (struct timespec t, char sbuf[TIMESPEC_STRSIZE_BOUND])
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||
{
|
||
time_t s = t.tv_sec;
|
||
int ns = t.tv_nsec;
|
||
char *np;
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||
bool negative = s < 0;
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||
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||
if (negative && ns != 0)
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||
{
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||
s++;
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||
ns = BILLION - ns;
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||
}
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||
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||
np = umaxtostr (negative ? - (uintmax_t) s : (uintmax_t) s, sbuf + 1);
|
||
if (negative)
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||
*--np = '-';
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code_ns_fraction (ns, sbuf + UINTMAX_STRSIZE_BOUND);
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||
return np;
|
||
}
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||
|
||
/* File handling. */
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||
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||
/* Saved names in case backup needs to be undone. */
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||
static char *before_backup_name;
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||
static char *after_backup_name;
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||
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||
/* Return 1 if FILE_NAME is obviously "." or "/". */
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||
static bool
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||
must_be_dot_or_slash (char const *file_name)
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||
{
|
||
file_name += FILE_SYSTEM_PREFIX_LEN (file_name);
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||
|
||
if (ISSLASH (file_name[0]))
|
||
{
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||
for (;;)
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||
if (ISSLASH (file_name[1]))
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||
file_name++;
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||
else if (file_name[1] == '.'
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||
&& ISSLASH (file_name[2 + (file_name[2] == '.')]))
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||
file_name += 2 + (file_name[2] == '.');
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||
else
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return ! file_name[1];
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||
}
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||
else
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||
{
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||
while (file_name[0] == '.' && ISSLASH (file_name[1]))
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||
{
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file_name += 2;
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||
while (ISSLASH (*file_name))
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||
file_name++;
|
||
}
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||
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||
return ! file_name[0] || (file_name[0] == '.' && ! file_name[1]);
|
||
}
|
||
}
|
||
|
||
/* Some implementations of rmdir let you remove '.' or '/'.
|
||
Report an error with errno set to zero for obvious cases of this;
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||
otherwise call rmdir. */
|
||
static int
|
||
safer_rmdir (const char *file_name)
|
||
{
|
||
if (must_be_dot_or_slash (file_name))
|
||
{
|
||
errno = 0;
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||
return -1;
|
||
}
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||
|
||
return rmdir (file_name);
|
||
}
|
||
|
||
/* Remove FILE_NAME, returning 1 on success. If FILE_NAME is a directory,
|
||
then if OPTION is RECURSIVE_REMOVE_OPTION is set remove FILE_NAME
|
||
recursively; otherwise, remove it only if it is empty. If FILE_NAME is
|
||
a directory that cannot be removed (e.g., because it is nonempty)
|
||
and if OPTION is WANT_DIRECTORY_REMOVE_OPTION, then return -1.
|
||
Return 0 on error, with errno set; if FILE_NAME is obviously the working
|
||
directory return zero with errno set to zero. */
|
||
int
|
||
remove_any_file (const char *file_name, enum remove_option option)
|
||
{
|
||
/* Try unlink first if we cannot unlink directories, as this saves
|
||
us a system call in the common case where we're removing a
|
||
non-directory. */
|
||
bool try_unlink_first = cannot_unlink_dir ();
|
||
|
||
if (try_unlink_first)
|
||
{
|
||
if (unlink (file_name) == 0)
|
||
return 1;
|
||
|
||
/* POSIX 1003.1-2001 requires EPERM when attempting to unlink a
|
||
directory without appropriate privileges, but many Linux
|
||
kernels return the more-sensible EISDIR. */
|
||
if (errno != EPERM && errno != EISDIR)
|
||
return 0;
|
||
}
|
||
|
||
if (safer_rmdir (file_name) == 0)
|
||
return 1;
|
||
|
||
switch (errno)
|
||
{
|
||
case ENOTDIR:
|
||
return !try_unlink_first && unlink (file_name) == 0;
|
||
|
||
case 0:
|
||
case EEXIST:
|
||
#if defined ENOTEMPTY && ENOTEMPTY != EEXIST
|
||
case ENOTEMPTY:
|
||
#endif
|
||
switch (option)
|
||
{
|
||
case ORDINARY_REMOVE_OPTION:
|
||
break;
|
||
|
||
case WANT_DIRECTORY_REMOVE_OPTION:
|
||
return -1;
|
||
|
||
case RECURSIVE_REMOVE_OPTION:
|
||
{
|
||
char *directory = savedir (file_name);
|
||
char const *entry;
|
||
size_t entrylen;
|
||
|
||
if (! directory)
|
||
return 0;
|
||
|
||
for (entry = directory;
|
||
(entrylen = strlen (entry)) != 0;
|
||
entry += entrylen + 1)
|
||
{
|
||
char *file_name_buffer = new_name (file_name, entry);
|
||
int r = remove_any_file (file_name_buffer,
|
||
RECURSIVE_REMOVE_OPTION);
|
||
int e = errno;
|
||
free (file_name_buffer);
|
||
|
||
if (! r)
|
||
{
|
||
free (directory);
|
||
errno = e;
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
free (directory);
|
||
return safer_rmdir (file_name) == 0;
|
||
}
|
||
}
|
||
break;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Check if FILE_NAME already exists and make a backup of it right now.
|
||
Return success (nonzero) only if the backup is either unneeded, or
|
||
successful. For now, directories are considered to never need
|
||
backup. If THIS_IS_THE_ARCHIVE is nonzero, this is the archive and
|
||
so, we do not have to backup block or character devices, nor remote
|
||
entities. */
|
||
bool
|
||
maybe_backup_file (const char *file_name, bool this_is_the_archive)
|
||
{
|
||
struct stat file_stat;
|
||
|
||
/* Check if we really need to backup the file. */
|
||
|
||
if (this_is_the_archive && _remdev (file_name))
|
||
return true;
|
||
|
||
if (stat (file_name, &file_stat))
|
||
{
|
||
if (errno == ENOENT)
|
||
return true;
|
||
|
||
stat_error (file_name);
|
||
return false;
|
||
}
|
||
|
||
if (S_ISDIR (file_stat.st_mode))
|
||
return true;
|
||
|
||
if (this_is_the_archive
|
||
&& (S_ISBLK (file_stat.st_mode) || S_ISCHR (file_stat.st_mode)))
|
||
return true;
|
||
|
||
assign_string (&before_backup_name, file_name);
|
||
|
||
/* A run situation may exist between Emacs or other GNU programs trying to
|
||
make a backup for the same file simultaneously. If theoretically
|
||
possible, real problems are unlikely. Doing any better would require a
|
||
convention, GNU-wide, for all programs doing backups. */
|
||
|
||
assign_string (&after_backup_name, 0);
|
||
after_backup_name = find_backup_file_name (file_name, backup_type);
|
||
if (! after_backup_name)
|
||
xalloc_die ();
|
||
|
||
if (rename (before_backup_name, after_backup_name) == 0)
|
||
{
|
||
if (verbose_option)
|
||
fprintf (stdlis, _("Renaming %s to %s\n"),
|
||
quote_n (0, before_backup_name),
|
||
quote_n (1, after_backup_name));
|
||
return true;
|
||
}
|
||
else
|
||
{
|
||
/* The backup operation failed. */
|
||
int e = errno;
|
||
ERROR ((0, e, _("%s: Cannot rename to %s"),
|
||
quotearg_colon (before_backup_name),
|
||
quote_n (1, after_backup_name)));
|
||
assign_string (&after_backup_name, 0);
|
||
return false;
|
||
}
|
||
}
|
||
|
||
/* Try to restore the recently backed up file to its original name.
|
||
This is usually only needed after a failed extraction. */
|
||
void
|
||
undo_last_backup (void)
|
||
{
|
||
if (after_backup_name)
|
||
{
|
||
if (rename (after_backup_name, before_backup_name) != 0)
|
||
{
|
||
int e = errno;
|
||
ERROR ((0, e, _("%s: Cannot rename to %s"),
|
||
quotearg_colon (after_backup_name),
|
||
quote_n (1, before_backup_name)));
|
||
}
|
||
if (verbose_option)
|
||
fprintf (stdlis, _("Renaming %s back to %s\n"),
|
||
quote_n (0, after_backup_name),
|
||
quote_n (1, before_backup_name));
|
||
assign_string (&after_backup_name, 0);
|
||
}
|
||
}
|
||
|
||
/* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
|
||
int
|
||
deref_stat (bool deref, char const *name, struct stat *buf)
|
||
{
|
||
return deref ? stat (name, buf) : lstat (name, buf);
|
||
}
|
||
|
||
/* Set FD's (i.e., FILE's) access time to TIMESPEC[0]. If that's not
|
||
possible to do by itself, set its access and data modification
|
||
times to TIMESPEC[0] and TIMESPEC[1], respectively. */
|
||
int
|
||
set_file_atime (int fd, char const *file, struct timespec const timespec[2])
|
||
{
|
||
#ifdef _FIOSATIME
|
||
if (0 <= fd)
|
||
{
|
||
struct timeval timeval;
|
||
timeval.tv_sec = timespec[0].tv_sec;
|
||
timeval.tv_usec = timespec[0].tv_nsec / 1000;
|
||
if (ioctl (fd, _FIOSATIME, &timeval) == 0)
|
||
return 0;
|
||
}
|
||
#endif
|
||
|
||
return gl_futimens (fd, file, timespec);
|
||
}
|
||
|
||
/* A description of a working directory. */
|
||
struct wd
|
||
{
|
||
char const *name;
|
||
int saved;
|
||
struct saved_cwd saved_cwd;
|
||
};
|
||
|
||
/* A vector of chdir targets. wd[0] is the initial working directory. */
|
||
static struct wd *wd;
|
||
|
||
/* The number of working directories in the vector. */
|
||
static size_t wds;
|
||
|
||
/* The allocated size of the vector. */
|
||
static size_t wd_alloc;
|
||
|
||
/* DIR is the operand of a -C option; add it to vector of chdir targets,
|
||
and return the index of its location. */
|
||
int
|
||
chdir_arg (char const *dir)
|
||
{
|
||
if (wds == wd_alloc)
|
||
{
|
||
if (wd_alloc == 0)
|
||
{
|
||
wd_alloc = 2;
|
||
wd = xmalloc (sizeof *wd * wd_alloc);
|
||
}
|
||
else
|
||
wd = x2nrealloc (wd, &wd_alloc, sizeof *wd);
|
||
|
||
if (! wds)
|
||
{
|
||
wd[wds].name = ".";
|
||
wd[wds].saved = 0;
|
||
wds++;
|
||
}
|
||
}
|
||
|
||
/* Optimize the common special case of the working directory,
|
||
or the working directory as a prefix. */
|
||
if (dir[0])
|
||
{
|
||
while (dir[0] == '.' && ISSLASH (dir[1]))
|
||
for (dir += 2; ISSLASH (*dir); dir++)
|
||
continue;
|
||
if (! dir[dir[0] == '.'])
|
||
return wds - 1;
|
||
}
|
||
|
||
wd[wds].name = dir;
|
||
wd[wds].saved = 0;
|
||
return wds++;
|
||
}
|
||
|
||
/* Change to directory I. If I is 0, change to the initial working
|
||
directory; otherwise, I must be a value returned by chdir_arg. */
|
||
void
|
||
chdir_do (int i)
|
||
{
|
||
static int previous;
|
||
|
||
if (previous != i)
|
||
{
|
||
struct wd *prev = &wd[previous];
|
||
struct wd *curr = &wd[i];
|
||
|
||
if (! prev->saved)
|
||
{
|
||
int err = 0;
|
||
prev->saved = 1;
|
||
if (save_cwd (&prev->saved_cwd) != 0)
|
||
err = errno;
|
||
else if (0 <= prev->saved_cwd.desc)
|
||
{
|
||
/* Make sure we still have at least one descriptor available. */
|
||
int fd1 = prev->saved_cwd.desc;
|
||
int fd2 = dup (fd1);
|
||
if (0 <= fd2)
|
||
close (fd2);
|
||
else if (errno == EMFILE)
|
||
{
|
||
/* Force restore_cwd to use chdir_long. */
|
||
close (fd1);
|
||
prev->saved_cwd.desc = -1;
|
||
prev->saved_cwd.name = xgetcwd ();
|
||
}
|
||
else
|
||
err = errno;
|
||
}
|
||
|
||
if (err)
|
||
FATAL_ERROR ((0, err, _("Cannot save working directory")));
|
||
}
|
||
|
||
if (curr->saved)
|
||
{
|
||
if (restore_cwd (&curr->saved_cwd))
|
||
FATAL_ERROR ((0, 0, _("Cannot change working directory")));
|
||
}
|
||
else
|
||
{
|
||
if (i && ! ISSLASH (curr->name[0]))
|
||
chdir_do (i - 1);
|
||
if (chdir (curr->name) != 0)
|
||
chdir_fatal (curr->name);
|
||
}
|
||
|
||
previous = i;
|
||
}
|
||
}
|
||
|
||
void
|
||
close_diag (char const *name)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
close_warn (name);
|
||
else
|
||
close_error (name);
|
||
}
|
||
|
||
void
|
||
open_diag (char const *name)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
open_warn (name);
|
||
else
|
||
open_error (name);
|
||
}
|
||
|
||
void
|
||
read_diag_details (char const *name, off_t offset, size_t size)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
read_warn_details (name, offset, size);
|
||
else
|
||
read_error_details (name, offset, size);
|
||
}
|
||
|
||
void
|
||
readlink_diag (char const *name)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
readlink_warn (name);
|
||
else
|
||
readlink_error (name);
|
||
}
|
||
|
||
void
|
||
savedir_diag (char const *name)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
savedir_warn (name);
|
||
else
|
||
savedir_error (name);
|
||
}
|
||
|
||
void
|
||
seek_diag_details (char const *name, off_t offset)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
seek_warn_details (name, offset);
|
||
else
|
||
seek_error_details (name, offset);
|
||
}
|
||
|
||
void
|
||
stat_diag (char const *name)
|
||
{
|
||
if (ignore_failed_read_option)
|
||
stat_warn (name);
|
||
else
|
||
stat_error (name);
|
||
}
|
||
|
||
void
|
||
write_fatal_details (char const *name, ssize_t status, size_t size)
|
||
{
|
||
write_error_details (name, status, size);
|
||
fatal_exit ();
|
||
}
|
||
|
||
/* Fork, aborting if unsuccessful. */
|
||
pid_t
|
||
xfork (void)
|
||
{
|
||
pid_t p = fork ();
|
||
if (p == (pid_t) -1)
|
||
call_arg_fatal ("fork", _("child process"));
|
||
return p;
|
||
}
|
||
|
||
/* Create a pipe, aborting if unsuccessful. */
|
||
void
|
||
xpipe (int fd[2])
|
||
{
|
||
if (pipe (fd) < 0)
|
||
call_arg_fatal ("pipe", _("interprocess channel"));
|
||
}
|
||
|
||
/* Return PTR, aligned upward to the next multiple of ALIGNMENT.
|
||
ALIGNMENT must be nonzero. The caller must arrange for ((char *)
|
||
PTR) through ((char *) PTR + ALIGNMENT - 1) to be addressable
|
||
locations. */
|
||
|
||
static inline void *
|
||
ptr_align (void *ptr, size_t alignment)
|
||
{
|
||
char *p0 = ptr;
|
||
char *p1 = p0 + alignment - 1;
|
||
return p1 - (size_t) p1 % alignment;
|
||
}
|
||
|
||
/* Return the address of a page-aligned buffer of at least SIZE bytes.
|
||
The caller should free *PTR when done with the buffer. */
|
||
|
||
void *
|
||
page_aligned_alloc (void **ptr, size_t size)
|
||
{
|
||
size_t alignment = getpagesize ();
|
||
size_t size1 = size + alignment;
|
||
if (size1 < size)
|
||
xalloc_die ();
|
||
*ptr = xmalloc (size1);
|
||
return ptr_align (*ptr, alignment);
|
||
}
|