/* modechange.c -- file mode manipulation
- Copyright (C) 1989, 1990, 1997, 1998, 1999, 2001, 2003, 2004, 2005
- Free Software Foundation, Inc.
+ Copyright (C) 1989, 1990, 1997, 1998, 1999, 2001, 2003, 2004, 2005,
+ 2006 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ 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 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, 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
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. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by David MacKenzie <djm@ai.mit.edu> */
changing the mode of many files, this probably results in a
performance gain. */
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
#include "modechange.h"
#include <sys/stat.h>
#define XOTH 00001
#define ALLM 07777 /* all octal mode bits */
+/* Convert OCTAL, which uses one of the traditional octal values, to
+ an internal mode_t value. */
+static mode_t
+octal_to_mode (unsigned int octal)
+{
+ /* Help the compiler optimize the usual case where mode_t uses
+ the traditional octal representation. */
+ return ((S_ISUID == SUID && S_ISGID == SGID && S_ISVTX == SVTX
+ && S_IRUSR == RUSR && S_IWUSR == WUSR && S_IXUSR == XUSR
+ && S_IRGRP == RGRP && S_IWGRP == WGRP && S_IXGRP == XGRP
+ && S_IROTH == ROTH && S_IWOTH == WOTH && S_IXOTH == XOTH)
+ ? octal
+ : (mode_t) ((octal & SUID ? S_ISUID : 0)
+ | (octal & SGID ? S_ISGID : 0)
+ | (octal & SVTX ? S_ISVTX : 0)
+ | (octal & RUSR ? S_IRUSR : 0)
+ | (octal & WUSR ? S_IWUSR : 0)
+ | (octal & XUSR ? S_IXUSR : 0)
+ | (octal & RGRP ? S_IRGRP : 0)
+ | (octal & WGRP ? S_IWGRP : 0)
+ | (octal & XGRP ? S_IXGRP : 0)
+ | (octal & ROTH ? S_IROTH : 0)
+ | (octal & WOTH ? S_IWOTH : 0)
+ | (octal & XOTH ? S_IXOTH : 0)));
+}
+
/* Special operations flags. */
enum
{
char flag; /* Special operations flag. */
mode_t affected; /* Set for u, g, o, or a. */
mode_t value; /* Bits to add/remove. */
+ mode_t mentioned; /* Bits explicitly mentioned. */
};
/* Return a mode_change array with the specified `=ddd'-style
- mode change operation, where NEW_MODE is `ddd'. */
+ mode change operation, where NEW_MODE is `ddd' and MENTIONED
+ contains the bits explicitly mentioned in the mode are MENTIONED. */
static struct mode_change *
-make_node_op_equals (mode_t new_mode)
+make_node_op_equals (mode_t new_mode, mode_t mentioned)
{
struct mode_change *p = xmalloc (2 * sizeof *p);
p->op = '=';
p->flag = MODE_ORDINARY_CHANGE;
p->affected = CHMOD_MODE_BITS;
p->value = new_mode;
+ p->mentioned = mentioned;
p[1].flag = MODE_DONE;
return p;
}
if ('0' <= *mode_string && *mode_string < '8')
{
+ unsigned int octal_mode = 0;
mode_t mode;
- unsigned int octal_value = 0;
+ mode_t mentioned;
do
{
- octal_value = 8 * octal_value + *mode_string++ - '0';
- if (ALLM < octal_value)
+ octal_mode = 8 * octal_mode + *mode_string++ - '0';
+ if (ALLM < octal_mode)
return NULL;
}
while ('0' <= *mode_string && *mode_string < '8');
- /* Help the compiler optimize the usual case where mode_t uses
- the traditional octal representation. */
- mode = ((S_ISUID == SUID && S_ISGID == SGID && S_ISVTX == SVTX
- && S_IRUSR == RUSR && S_IWUSR == WUSR && S_IXUSR == XUSR
- && S_IRGRP == RGRP && S_IWGRP == WGRP && S_IXGRP == XGRP
- && S_IROTH == ROTH && S_IWOTH == WOTH && S_IXOTH == XOTH)
- ? octal_value
- : (mode_t) ((octal_value & SUID ? S_ISUID : 0)
- | (octal_value & SGID ? S_ISGID : 0)
- | (octal_value & SVTX ? S_ISVTX : 0)
- | (octal_value & RUSR ? S_IRUSR : 0)
- | (octal_value & WUSR ? S_IWUSR : 0)
- | (octal_value & XUSR ? S_IXUSR : 0)
- | (octal_value & RGRP ? S_IRGRP : 0)
- | (octal_value & WGRP ? S_IWGRP : 0)
- | (octal_value & XGRP ? S_IXGRP : 0)
- | (octal_value & ROTH ? S_IROTH : 0)
- | (octal_value & WOTH ? S_IWOTH : 0)
- | (octal_value & XOTH ? S_IXOTH : 0)));
-
- return make_node_op_equals (mode);
+ if (*mode_string)
+ return NULL;
+
+ mode = octal_to_mode (octal_mode);
+ mentioned = (mode & (S_ISUID | S_ISGID)) | S_ISVTX | S_IRWXUGO;
+ return make_node_op_equals (mode, mentioned);
}
/* Allocate enough space to hold the result. */
change->flag = flag;
change->affected = affected;
change->value = value;
+ change->mentioned = (affected ? affected & value : value);
}
while (*mode_string == '=' || *mode_string == '+'
|| *mode_string == '-');
if (stat (ref_file, &ref_stats) != 0)
return NULL;
- return make_node_op_equals (ref_stats.st_mode);
+ return make_node_op_equals (ref_stats.st_mode, CHMOD_MODE_BITS);
}
-/* Return file mode OLDMODE, adjusted as indicated by the list of change
- operations CHANGES, which are interpreted assuming the umask is
- UMASK_VALUE. If OLDMODE is a directory, the type `X'
- change affects it even if no execute bits were set in OLDMODE.
- The returned value has the S_IFMT bits cleared. */
+/* Return the file mode bits of OLDMODE (which is the mode of a
+ directory if DIR), assuming the umask is UMASK_VALUE, adjusted as
+ indicated by the list of change operations CHANGES. If DIR, the
+ type 'X' change affects the returned value even if no execute bits
+ were set in OLDMODE, and set user and group ID bits are preserved
+ unless CHANGES mentioned them. If PMODE_BITS is not null, store into
+ *PMODE_BITS a mask denoting file mode bits that are affected by
+ CHANGES.
+
+ The returned value and *PMODE_BITS contain only file mode bits.
+ For example, they have the S_IFMT bits cleared on a standard
+ Unix-like host. */
mode_t
-mode_adjust (mode_t oldmode, struct mode_change const *changes,
- mode_t umask_value)
+mode_adjust (mode_t oldmode, bool dir, mode_t umask_value,
+ struct mode_change const *changes, mode_t *pmode_bits)
{
/* The adjusted mode. */
mode_t newmode = oldmode & CHMOD_MODE_BITS;
+ /* File mode bits that CHANGES cares about. */
+ mode_t mode_bits = 0;
+
for (; changes->flag != MODE_DONE; changes++)
{
mode_t affected = changes->affected;
+ mode_t omit_change =
+ (dir ? S_ISUID | S_ISGID : 0) & ~ changes->mentioned;
mode_t value = changes->value;
switch (changes->flag)
case MODE_X_IF_ANY_X:
/* Affect the execute bits if execute bits are already set
or if the file is a directory. */
- if ((newmode & (S_IXUSR | S_IXGRP | S_IXOTH)) || S_ISDIR (oldmode))
+ if ((newmode & (S_IXUSR | S_IXGRP | S_IXOTH)) | dir)
value |= S_IXUSR | S_IXGRP | S_IXOTH;
break;
}
/* If WHO was specified, limit the change to the affected bits.
- Otherwise, apply the umask. */
- value &= (affected ? affected : ~umask_value);
+ Otherwise, apply the umask. Either way, omit changes as
+ requested. */
+ value &= (affected ? affected : ~umask_value) & ~ omit_change;
switch (changes->op)
{
/* If WHO was specified, preserve the previous values of
bits that are not affected by this change operation.
Otherwise, clear all the bits. */
- newmode = (affected ? newmode & ~affected : 0);
- /* Fall through. */
+ {
+ mode_t preserved = (affected ? ~affected : 0) | omit_change;
+ mode_bits |= CHMOD_MODE_BITS & ~preserved;
+ newmode = (newmode & preserved) | value;
+ break;
+ }
+
case '+':
+ mode_bits |= value;
newmode |= value;
break;
case '-':
+ mode_bits |= value;
newmode &= ~value;
break;
}
}
+ if (pmode_bits)
+ *pmode_bits = mode_bits;
return newmode;
}
projects / gnulib.git / blobdiff