X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmodechange.c;h=9b4e23f4be7450ac34f4817518f1d5b90d11ddf9;hb=8d53196a5a3408315e6ed3410973d3bd16a8a3e9;hp=ef484c0fbc113638488b8f6c290c41e42353ad9c;hpb=e0a31ac6dea7e840e3516a56b330a995af527144;p=gnulib.git
diff --git a/lib/modechange.c b/lib/modechange.c
index ef484c0fb..9b4e23f4b 100644
--- a/lib/modechange.c
+++ b/lib/modechange.c
@@ -1,10 +1,12 @@
/* modechange.c -- file mode manipulation
- Copyright (C) 1989, 1990, 1997, 1998, 1999 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1989-1990, 1997-1999, 2001, 2003-2006, 2009-2010 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 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
@@ -12,434 +14,372 @@
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ along with this program. If not, see . */
/* Written by David MacKenzie */
-/* The ASCII mode string is compiled into a linked list of `struct
+/* The ASCII mode string is compiled into an array of `struct
modechange', which can then be applied to each file to be changed.
We do this instead of re-parsing the ASCII string for each file
because the compiled form requires less computation to use; when
changing the mode of many files, this probably results in a
- performance gain. */
+ performance gain. */
-#if HAVE_CONFIG_H
-# include
-#endif
+#include
#include "modechange.h"
#include
-#include "xstrtol.h"
-
-#if STDC_HEADERS
-# include
-#else
-char *malloc ();
-#endif
-
-#ifndef NULL
-# define NULL 0
-#endif
-
-#if STAT_MACROS_BROKEN
-# undef S_ISDIR
-#endif
-
-#if !defined(S_ISDIR) && defined(S_IFDIR)
-# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
-#endif
-
-#ifndef S_ISUID
-# define S_ISUID 04000
-#endif
-#ifndef S_ISGID
-# define S_ISGID 04000
-#endif
-#ifndef S_ISVTX
-# define S_ISVTX 01000
-#endif
-#ifndef S_IRUSR
-# define S_IRUSR 0400
-#endif
-#ifndef S_IWUSR
-# define S_IWUSR 0200
-#endif
-#ifndef S_IXUSR
-# define S_IXUSR 0100
-#endif
-#ifndef S_IRGRP
-# define S_IRGRP 0040
-#endif
-#ifndef S_IWGRP
-# define S_IWGRP 0020
-#endif
-#ifndef S_IXGRP
-# define S_IXGRP 0010
-#endif
-#ifndef S_IROTH
-# define S_IROTH 0004
-#endif
-#ifndef S_IWOTH
-# define S_IWOTH 0002
-#endif
-#ifndef S_IXOTH
-# define S_IXOTH 0001
-#endif
-#ifndef S_IRWXU
-# define S_IRWXU 0700
-#endif
-#ifndef S_IRWXG
-# define S_IRWXG 0070
-#endif
-#ifndef S_IRWXO
-# define S_IRWXO 0007
-#endif
-
-/* All the mode bits that can be affected by chmod. */
-#define CHMOD_MODE_BITS \
- (S_ISUID | S_ISGID | S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO)
-
-/* Return newly allocated memory to hold one element of type TYPE. */
-#define talloc(type) ((type *) malloc (sizeof (type)))
-
-/* Create a mode_change entry with the specified `=ddd'-style
- mode change operation, where NEW_MODE is `ddd'. Return the
- new entry, or NULL upon failure. */
+#include "stat-macros.h"
+#include "xalloc.h"
+#include
+
+/* The traditional octal values corresponding to each mode bit. */
+#define SUID 04000
+#define SGID 02000
+#define SVTX 01000
+#define RUSR 00400
+#define WUSR 00200
+#define XUSR 00100
+#define RGRP 00040
+#define WGRP 00020
+#define XGRP 00010
+#define ROTH 00004
+#define WOTH 00002
+#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
+ {
+ /* For the sentinel at the end of the mode changes array. */
+ MODE_DONE,
+
+ /* The typical case. */
+ MODE_ORDINARY_CHANGE,
+
+ /* In addition to the typical case, affect the execute bits if at
+ least one execute bit is set already, or if the file is a
+ directory. */
+ MODE_X_IF_ANY_X,
+
+ /* Instead of the typical case, copy some existing permissions for
+ u, g, or o onto the other two. Which of u, g, or o is copied
+ is determined by which bits are set in the `value' field. */
+ MODE_COPY_EXISTING
+ };
+
+/* Description of a mode change. */
+struct mode_change
+{
+ char op; /* One of "=+-". */
+ 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' 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;
- p = talloc (struct mode_change);
- if (p == NULL)
- return p;
- p->next = NULL;
+ struct mode_change *p = xmalloc (2 * sizeof *p);
p->op = '=';
- p->flags = 0;
+ p->flag = MODE_ORDINARY_CHANGE;
+ p->affected = CHMOD_MODE_BITS;
p->value = new_mode;
- p->affected = CHMOD_MODE_BITS; /* Affect all permissions. */
+ p->mentioned = mentioned;
+ p[1].flag = MODE_DONE;
return p;
}
-/* Append entry E to the end of the link list with the specified
- HEAD and TAIL. */
-
-static void
-mode_append_entry (struct mode_change **head,
- struct mode_change **tail,
- struct mode_change *e)
-{
- if (*head == NULL)
- *head = *tail = e;
- else
- {
- (*tail)->next = e;
- *tail = e;
- }
-}
-
-/* Return a linked list of file mode change operations created from
+/* Return a pointer to an array of file mode change operations created from
MODE_STRING, an ASCII string that contains either an octal number
specifying an absolute mode, or symbolic mode change operations with
the form:
[ugoa...][[+-=][rwxXstugo...]...][,...]
- MASKED_OPS is a bitmask indicating which symbolic mode operators (=+-)
- should not affect bits set in the umask when no users are given.
- Operators not selected in MASKED_OPS ignore the umask.
- Return MODE_INVALID if `mode_string' does not contain a valid
- representation of file mode change operations;
- return MODE_MEMORY_EXHAUSTED if there is insufficient memory. */
+ Return NULL if `mode_string' does not contain a valid
+ representation of file mode change operations. */
struct mode_change *
-mode_compile (const char *mode_string, unsigned int masked_ops)
+mode_compile (char const *mode_string)
{
- struct mode_change *head; /* First element of the linked list. */
- struct mode_change *tail; /* An element of the linked list. */
- uintmax_t mode_value; /* The mode value, if octal. */
- char *string_end; /* Pointer to end of parsed value. */
- mode_t umask_value; /* The umask value (surprise). */
-
- head = NULL;
-#ifdef lint
- tail = NULL;
-#endif
-
- if (xstrtoumax (mode_string, &string_end, 8, &mode_value, "") == LONGINT_OK)
+ /* The array of mode-change directives to be returned. */
+ struct mode_change *mc;
+ size_t used = 0;
+
+ if ('0' <= *mode_string && *mode_string < '8')
{
- struct mode_change *p;
- if (mode_value != (mode_value & CHMOD_MODE_BITS))
- return MODE_INVALID;
- p = make_node_op_equals ((mode_t) mode_value);
- if (p == NULL)
- return MODE_MEMORY_EXHAUSTED;
- mode_append_entry (&head, &tail, p);
- return head;
+ unsigned int octal_mode = 0;
+ mode_t mode;
+ mode_t mentioned;
+
+ do
+ {
+ octal_mode = 8 * octal_mode + *mode_string++ - '0';
+ if (ALLM < octal_mode)
+ return NULL;
+ }
+ while ('0' <= *mode_string && *mode_string < '8');
+
+ 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);
}
- umask_value = umask (0);
- umask (umask_value); /* Restore the old value. */
- --mode_string;
-
- /* One loop iteration for each "ugoa...=+-rwxXstugo...[=+-rwxXstugo...]". */
- do
+ /* Allocate enough space to hold the result. */
+ {
+ size_t needed = 1;
+ char const *p;
+ for (p = mode_string; *p; p++)
+ needed += (*p == '=' || *p == '+' || *p == '-');
+ mc = xnmalloc (needed, sizeof *mc);
+ }
+
+ /* One loop iteration for each `[ugoa]*([-+=]([rwxXst]*|[ugo]))+'. */
+ for (;; mode_string++)
{
- /* Which bits in the mode are operated on. */
- mode_t affected_bits = 0;
- /* `affected_bits' modified by umask. */
- mode_t affected_masked;
- /* Operators to actually use umask on. */
- unsigned ops_to_mask = 0;
-
- int who_specified_p;
-
- affected_bits = 0;
- ops_to_mask = 0;
- /* Turn on all the bits in `affected_bits' for each group given. */
- for (++mode_string;; ++mode_string)
- switch (*mode_string)
- {
- case 'u':
- affected_bits |= S_ISUID | S_IRWXU;
- break;
- case 'g':
- affected_bits |= S_ISGID | S_IRWXG;
- break;
- case 'o':
- affected_bits |= S_ISVTX | S_IRWXO;
- break;
- case 'a':
- affected_bits |= CHMOD_MODE_BITS;
- break;
- default:
- goto no_more_affected;
- }
-
- no_more_affected:
- /* If none specified, affect all bits, except perhaps those
- set in the umask. */
- if (affected_bits)
- who_specified_p = 1;
- else
- {
- who_specified_p = 0;
- affected_bits = CHMOD_MODE_BITS;
- ops_to_mask = masked_ops;
- }
-
- while (*mode_string == '=' || *mode_string == '+' || *mode_string == '-')
- {
- struct mode_change *change = talloc (struct mode_change);
- if (change == NULL)
- {
- mode_free (head);
- return MODE_MEMORY_EXHAUSTED;
- }
-
- change->next = NULL;
- change->op = *mode_string; /* One of "=+-". */
- affected_masked = affected_bits;
-
- /* Per the Single Unix Spec, if `who' is not specified and the
- `=' operator is used, then clear all the bits first. */
- if (!who_specified_p &&
- ops_to_mask & (*mode_string == '=' ? MODE_MASK_EQUALS : 0))
- {
- struct mode_change *p = make_node_op_equals (0);
- if (p == NULL)
- return MODE_MEMORY_EXHAUSTED;
- mode_append_entry (&head, &tail, p);
- }
-
- if (ops_to_mask & (*mode_string == '=' ? MODE_MASK_EQUALS
- : *mode_string == '+' ? MODE_MASK_PLUS
- : MODE_MASK_MINUS))
- affected_masked &= ~umask_value;
- change->affected = affected_masked;
- change->value = 0;
- change->flags = 0;
-
- /* Add the element to the tail of the list, so the operations
- are performed in the correct order. */
- mode_append_entry (&head, &tail, change);
-
- /* Set `value' according to the bits set in `affected_masked'. */
- for (++mode_string;; ++mode_string)
- switch (*mode_string)
- {
- case 'r':
- change->value |= ((S_IRUSR | S_IRGRP | S_IROTH)
- & affected_masked);
- break;
- case 'w':
- change->value |= ((S_IWUSR | S_IWGRP | S_IWOTH)
- & affected_masked);
- break;
- case 'X':
- change->flags |= MODE_X_IF_ANY_X;
- /* Fall through. */
- case 'x':
- change->value |= ((S_IXUSR | S_IXGRP | S_IXOTH)
- & affected_masked);
- break;
- case 's':
- /* Set the setuid/gid bits if `u' or `g' is selected. */
- change->value |= (S_ISUID | S_ISGID) & affected_masked;
- break;
- case 't':
- /* Set the "save text image" bit if `o' is selected. */
- change->value |= S_ISVTX & affected_masked;
- break;
- case 'u':
- /* Set the affected bits to the value of the `u' bits
- on the same file. */
- if (change->value)
- goto invalid;
- change->value = S_IRWXU;
- change->flags |= MODE_COPY_EXISTING;
- break;
- case 'g':
- /* Set the affected bits to the value of the `g' bits
- on the same file. */
- if (change->value)
- goto invalid;
- change->value = S_IRWXG;
- change->flags |= MODE_COPY_EXISTING;
- break;
- case 'o':
- /* Set the affected bits to the value of the `o' bits
- on the same file. */
- if (change->value)
- goto invalid;
- change->value = S_IRWXO;
- change->flags |= MODE_COPY_EXISTING;
- break;
- default:
- goto no_more_values;
- }
- no_more_values:;
- }
- } while (*mode_string == ',');
+ /* Which bits in the mode are operated on. */
+ mode_t affected = 0;
+
+ /* Turn on all the bits in `affected' for each group given. */
+ for (;; mode_string++)
+ switch (*mode_string)
+ {
+ default:
+ goto invalid;
+ case 'u':
+ affected |= S_ISUID | S_IRWXU;
+ break;
+ case 'g':
+ affected |= S_ISGID | S_IRWXG;
+ break;
+ case 'o':
+ affected |= S_ISVTX | S_IRWXO;
+ break;
+ case 'a':
+ affected |= CHMOD_MODE_BITS;
+ break;
+ case '=': case '+': case '-':
+ goto no_more_affected;
+ }
+ no_more_affected:;
+
+ do
+ {
+ char op = *mode_string++;
+ mode_t value;
+ char flag = MODE_COPY_EXISTING;
+ struct mode_change *change;
+
+ switch (*mode_string++)
+ {
+ case 'u':
+ /* Set the affected bits to the value of the `u' bits
+ on the same file. */
+ value = S_IRWXU;
+ break;
+ case 'g':
+ /* Set the affected bits to the value of the `g' bits
+ on the same file. */
+ value = S_IRWXG;
+ break;
+ case 'o':
+ /* Set the affected bits to the value of the `o' bits
+ on the same file. */
+ value = S_IRWXO;
+ break;
+
+ default:
+ value = 0;
+ flag = MODE_ORDINARY_CHANGE;
+
+ for (mode_string--;; mode_string++)
+ switch (*mode_string)
+ {
+ case 'r':
+ value |= S_IRUSR | S_IRGRP | S_IROTH;
+ break;
+ case 'w':
+ value |= S_IWUSR | S_IWGRP | S_IWOTH;
+ break;
+ case 'x':
+ value |= S_IXUSR | S_IXGRP | S_IXOTH;
+ break;
+ case 'X':
+ flag = MODE_X_IF_ANY_X;
+ break;
+ case 's':
+ /* Set the setuid/gid bits if `u' or `g' is selected. */
+ value |= S_ISUID | S_ISGID;
+ break;
+ case 't':
+ /* Set the "save text image" bit if `o' is selected. */
+ value |= S_ISVTX;
+ break;
+ default:
+ goto no_more_values;
+ }
+ no_more_values:;
+ }
+
+ change = &mc[used++];
+ change->op = op;
+ change->flag = flag;
+ change->affected = affected;
+ change->value = value;
+ change->mentioned = (affected ? affected & value : value);
+ }
+ while (*mode_string == '=' || *mode_string == '+'
+ || *mode_string == '-');
+
+ if (*mode_string != ',')
+ break;
+ }
+
if (*mode_string == 0)
- return head;
+ {
+ mc[used].flag = MODE_DONE;
+ return mc;
+ }
+
invalid:
- mode_free (head);
- return MODE_INVALID;
+ free (mc);
+ return NULL;
}
/* Return a file mode change operation that sets permissions to match those
- of REF_FILE. Return MODE_BAD_REFERENCE if REF_FILE can't be accessed. */
+ of REF_FILE. Return NULL (setting errno) if REF_FILE can't be accessed. */
struct mode_change *
mode_create_from_ref (const char *ref_file)
{
- struct mode_change *change; /* the only change element */
struct stat ref_stats;
- if (stat (ref_file, &ref_stats))
- return MODE_BAD_REFERENCE;
-
- change = talloc (struct mode_change);
-
- if (change == NULL)
- return MODE_MEMORY_EXHAUSTED;
-
- change->op = '=';
- change->flags = 0;
- change->affected = CHMOD_MODE_BITS;
- change->value = ref_stats.st_mode;
- change->next = NULL;
-
- return change;
+ if (stat (ref_file, &ref_stats) != 0)
+ return NULL;
+ 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. 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, const struct mode_change *changes)
+mode_adjust (mode_t oldmode, bool dir, mode_t umask_value,
+ struct mode_change const *changes, mode_t *pmode_bits)
{
- mode_t newmode; /* The adjusted mode and one operand. */
- mode_t value; /* The other operand. */
+ /* The adjusted mode. */
+ mode_t newmode = oldmode & CHMOD_MODE_BITS;
- newmode = oldmode & CHMOD_MODE_BITS;
+ /* File mode bits that CHANGES cares about. */
+ mode_t mode_bits = 0;
- for (; changes; changes = changes->next)
+ for (; changes->flag != MODE_DONE; changes++)
{
- if (changes->flags & MODE_COPY_EXISTING)
- {
- /* Isolate in `value' the bits in `newmode' to copy, given in
- the mask `changes->value'. */
- value = newmode & changes->value;
-
- if (changes->value & S_IRWXU)
- /* Copy `u' permissions onto `g' and `o'. */
- value |= ((value & S_IRUSR ? S_IRGRP | S_IROTH : 0)
- | (value & S_IWUSR ? S_IWGRP | S_IROTH : 0)
- | (value & S_IXUSR ? S_IXGRP | S_IXOTH : 0));
- else if (changes->value & S_IRWXG)
- /* Copy `g' permissions onto `u' and `o'. */
- value |= ((value & S_IRGRP ? S_IRUSR | S_IROTH : 0)
- | (value & S_IWGRP ? S_IWUSR | S_IROTH : 0)
- | (value & S_IXGRP ? S_IXUSR | S_IXOTH : 0));
- else
- /* Copy `o' permissions onto `u' and `g'. */
- value |= ((value & S_IROTH ? S_IRUSR | S_IRGRP : 0)
- | (value & S_IWOTH ? S_IWUSR | S_IRGRP : 0)
- | (value & S_IXOTH ? S_IXUSR | S_IXGRP : 0));
-
- /* In order to change only `u', `g', or `o' permissions,
- or some combination thereof, clear unselected bits.
- This can not be done in mode_compile because the value
- to which the `changes->affected' mask is applied depends
- on the old mode of each file. */
- value &= changes->affected;
- }
- else
- {
- value = changes->value;
- /* If `X', do not affect the execute bits if the file is not a
- directory and no execute bits are already set. */
- if ((changes->flags & MODE_X_IF_ANY_X)
- && !S_ISDIR (oldmode)
- && (newmode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
- /* Clear the execute bits. */
- value &= ~ (S_IXUSR | S_IXGRP | S_IXOTH);
- }
+ 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_ORDINARY_CHANGE:
+ break;
+
+ case MODE_COPY_EXISTING:
+ /* Isolate in `value' the bits in `newmode' to copy. */
+ value &= newmode;
+
+ /* Copy the isolated bits to the other two parts. */
+ value |= ((value & (S_IRUSR | S_IRGRP | S_IROTH)
+ ? S_IRUSR | S_IRGRP | S_IROTH : 0)
+ | (value & (S_IWUSR | S_IWGRP | S_IWOTH)
+ ? S_IWUSR | S_IWGRP | S_IWOTH : 0)
+ | (value & (S_IXUSR | S_IXGRP | S_IXOTH)
+ ? S_IXUSR | S_IXGRP | S_IXOTH : 0));
+ break;
+
+ 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)) | dir)
+ value |= S_IXUSR | S_IXGRP | S_IXOTH;
+ break;
+ }
+
+ /* If WHO was specified, limit the change to the affected bits.
+ Otherwise, apply the umask. Either way, omit changes as
+ requested. */
+ value &= (affected ? affected : ~umask_value) & ~ omit_change;
switch (changes->op)
- {
- case '=':
- /* Preserve the previous values in `newmode' of bits that are
- not affected by this change operation. */
- newmode = (newmode & ~changes->affected) | value;
- break;
- case '+':
- newmode |= value;
- break;
- case '-':
- newmode &= ~value;
- break;
- }
+ {
+ case '=':
+ /* If WHO was specified, preserve the previous values of
+ bits that are not affected by this change operation.
+ Otherwise, clear all the bits. */
+ {
+ 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;
+ }
}
- return newmode;
-}
-/* Free the memory used by the list of file mode change operations
- CHANGES. */
-
-void
-mode_free (register struct mode_change *changes)
-{
- register struct mode_change *next;
-
- while (changes)
- {
- next = changes->next;
- free (changes);
- changes = next;
- }
+ if (pmode_bits)
+ *pmode_bits = mode_bits;
+ return newmode;
}