/* backupfile.c -- make Emacs style backup file names
- Copyright (C) 1990 Free Software Foundation, Inc.
+
+ Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
+ 1999, 2000, 2001, 2002, 2003 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
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+ along with this program; see the file COPYING.
+ If not, write to the Free Software Foundation,
+ 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
-/* David MacKenzie <djm@gnu.ai.mit.edu>.
+/* Written by David MacKenzie <djm@gnu.ai.mit.edu>.
Some algorithms adapted from GNU Emacs. */
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stddef.h>
#include <stdio.h>
-#include <ctype.h>
-#include <sys/types.h>
-#include "backupfile.h"
-#if defined(STDC_HEADERS) || defined(HAVE_STRING_H)
#include <string.h>
-#ifndef index
-#define index strchr
-#endif
-#ifndef rindex
-#define rindex strrchr
-#endif
+
+#if HAVE_DIRENT_H
+# include <dirent.h>
+# define NLENGTH(direct) strlen ((direct)->d_name)
#else
-#include <strings.h>
+# define dirent direct
+# define NLENGTH(direct) ((size_t) (direct)->d_namlen)
+# if HAVE_SYS_NDIR_H
+# include <sys/ndir.h>
+# endif
+# if HAVE_SYS_DIR_H
+# include <sys/dir.h>
+# endif
+# if HAVE_NDIR_H
+# include <ndir.h>
+# endif
#endif
-#if defined(DIRENT) || defined(_POSIX_VERSION)
-#include <dirent.h>
-#define NLENGTH(direct) (strlen((direct)->d_name))
-#else /* not (DIRENT or _POSIX_VERSION) */
-#define dirent direct
-#define NLENGTH(direct) ((direct)->d_namlen)
-#ifdef SYSNDIR
-#include <sys/ndir.h>
-#endif /* SYSNDIR */
-#ifdef SYSDIR
-#include <sys/dir.h>
-#endif /* SYSDIR */
-#ifdef NDIR
-#include <ndir.h>
-#endif /* NDIR */
-#endif /* DIRENT or _POSIX_VERSION */
-
-#ifdef VOID_CLOSEDIR
+#if CLOSEDIR_VOID
/* Fake a return value. */
-#define CLOSEDIR(d) (closedir (d), 0)
+# define CLOSEDIR(d) (closedir (d), 0)
#else
-#define CLOSEDIR(d) closedir (d)
+# define CLOSEDIR(d) closedir (d)
#endif
-#ifdef STDC_HEADERS
#include <stdlib.h>
+
+#if HAVE_DIRENT_H || HAVE_NDIR_H || HAVE_SYS_DIR_H || HAVE_SYS_NDIR_H
+# define HAVE_DIR 1
#else
-char *malloc ();
+# define HAVE_DIR 0
#endif
-#if !defined (isascii) || defined (STDC_HEADERS)
-#undef isascii
-#define isascii(c) 1
-#endif
+#include <limits.h>
-#define ISDIGIT(c) (isascii ((unsigned char ) c) \
- && isdigit ((unsigned char) (c)))
+/* Upper bound on the string length of an integer converted to string.
+ 302 / 1000 is ceil (log10 (2.0)). Subtract 1 for the sign bit;
+ add 1 for integer division truncation; add 1 more for a minus sign. */
+#define INT_STRLEN_BOUND(t) ((sizeof (t) * CHAR_BIT - 1) * 302 / 1000 + 2)
-#if defined (HAVE_UNISTD_H)
-#include <unistd.h>
-#endif
+/* ISDIGIT differs from isdigit, as follows:
+ - Its arg may be any int or unsigned int; it need not be an unsigned char.
+ - It's guaranteed to evaluate its argument exactly once.
+ - It's typically faster.
+ POSIX says that only '0' through '9' are digits. Prefer ISDIGIT to
+ ISDIGIT_LOCALE unless it's important to use the locale's definition
+ of `digit' even when the host does not conform to POSIX. */
+#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
-#if defined (_POSIX_VERSION)
-/* POSIX does not require that the d_ino field be present, and some
- systems do not provide it. */
-#define REAL_DIR_ENTRY(dp) 1
+#if D_INO_IN_DIRENT
+# define REAL_DIR_ENTRY(dp) ((dp)->d_ino != 0)
#else
-#define REAL_DIR_ENTRY(dp) ((dp)->d_ino != 0)
+# define REAL_DIR_ENTRY(dp) 1
#endif
-/* Which type of backup file names are generated. */
-enum backup_type backup_type = none;
+#include "argmatch.h"
+#include "backupfile.h"
+#include "dirname.h"
/* The extension added to file names to produce a simple (as opposed
to numbered) backup file name. */
-char *simple_backup_suffix = "~";
+const char *simple_backup_suffix = "~";
-char *basename ();
-char *dirname ();
-static char *concat ();
-char *find_backup_file_name ();
-static char *make_version_name ();
-static int max_backup_version ();
-static int version_number ();
+static int max_backup_version (const char *, const char *);
+static int version_number (const char *, const char *, size_t);
/* Return the name of the new backup file for file FILE,
allocated with malloc. Return 0 if out of memory.
Do not call this function if backup_type == none. */
char *
-find_backup_file_name (file)
- char *file;
+find_backup_file_name (const char *file, enum backup_type backup_type)
{
- char *dir;
- char *base_versions;
- int highest_backup;
-
- if (backup_type == simple)
- return concat (file, simple_backup_suffix);
- base_versions = concat (basename (file), ".~");
- if (base_versions == 0)
- return 0;
- dir = dirname (file);
- if (dir == 0)
+ size_t backup_suffix_size_max;
+ size_t file_len = strlen (file);
+ size_t numbered_suffix_size_max = INT_STRLEN_BOUND (int) + 4;
+ char *s;
+ const char *suffix = simple_backup_suffix;
+
+ /* Allow room for simple or `.~N~' backups. */
+ backup_suffix_size_max = strlen (simple_backup_suffix) + 1;
+ if (HAVE_DIR && backup_suffix_size_max < numbered_suffix_size_max)
+ backup_suffix_size_max = numbered_suffix_size_max;
+
+ s = malloc (file_len + 1
+ + backup_suffix_size_max + numbered_suffix_size_max);
+ if (s)
{
- free (base_versions);
- return 0;
+#if HAVE_DIR
+ if (backup_type != simple)
+ {
+ int highest_backup;
+ size_t dirlen = dir_len (file);
+
+ memcpy (s, file, dirlen);
+ if (dirlen == FILESYSTEM_PREFIX_LEN (file))
+ s[dirlen++] = '.';
+ s[dirlen] = '\0';
+ highest_backup = max_backup_version (base_name (file), s);
+ if (! (backup_type == numbered_existing && highest_backup == 0))
+ {
+ char *numbered_suffix = s + (file_len + backup_suffix_size_max);
+ sprintf (numbered_suffix, ".~%d~", highest_backup + 1);
+ suffix = numbered_suffix;
+ }
+ }
+#endif /* HAVE_DIR */
+
+ strcpy (s, file);
+ addext (s, suffix, '~');
}
- highest_backup = max_backup_version (base_versions, dir);
- free (base_versions);
- free (dir);
- if (backup_type == numbered_existing && highest_backup == 0)
- return concat (file, simple_backup_suffix);
- return make_version_name (file, highest_backup + 1);
+ return s;
}
+#if HAVE_DIR
+
/* Return the number of the highest-numbered backup file for file
FILE in directory DIR. If there are no numbered backups
of FILE in DIR, or an error occurs reading DIR, return 0.
- FILE should already have ".~" appended to it. */
+ */
static int
-max_backup_version (file, dir)
- char *file, *dir;
+max_backup_version (const char *file, const char *dir)
{
DIR *dirp;
struct dirent *dp;
int highest_version;
int this_version;
- int file_name_length;
-
+ size_t file_name_length;
+
dirp = opendir (dir);
if (!dirp)
return 0;
-
+
highest_version = 0;
- file_name_length = strlen (file);
+ file_name_length = base_len (file);
while ((dp = readdir (dirp)) != 0)
{
- if (!REAL_DIR_ENTRY (dp) || NLENGTH (dp) <= file_name_length)
+ if (!REAL_DIR_ENTRY (dp) || NLENGTH (dp) < file_name_length + 4)
continue;
-
+
this_version = version_number (file, dp->d_name, file_name_length);
if (this_version > highest_version)
highest_version = this_version;
return highest_version;
}
-/* Return a string, allocated with malloc, containing
- "FILE.~VERSION~". Return 0 if out of memory. */
-
-static char *
-make_version_name (file, version)
- char *file;
- int version;
-{
- char *backup_name;
-
- backup_name = malloc (strlen (file) + 16);
- if (backup_name == 0)
- return 0;
- sprintf (backup_name, "%s.~%d~", file, version);
- return backup_name;
-}
-
/* If BACKUP is a numbered backup of BASE, return its version number;
otherwise return 0. BASE_LENGTH is the length of BASE.
- BASE should already have ".~" appended to it. */
+ */
static int
-version_number (base, backup, base_length)
- char *base;
- char *backup;
- int base_length;
+version_number (const char *base, const char *backup, size_t base_length)
{
int version;
- char *p;
-
+ const char *p;
+
version = 0;
- if (!strncmp (base, backup, base_length) && ISDIGIT (backup[base_length]))
+ if (strncmp (base, backup, base_length) == 0
+ && backup[base_length] == '.'
+ && backup[base_length + 1] == '~')
{
- for (p = &backup[base_length]; ISDIGIT (*p); ++p)
+ for (p = &backup[base_length + 2]; ISDIGIT (*p); ++p)
version = version * 10 + *p - '0';
if (p[0] != '~' || p[1])
version = 0;
}
return version;
}
+#endif /* HAVE_DIR */
-/* Return the newly-allocated concatenation of STR1 and STR2.
- If out of memory, return 0. */
-
-static char *
-concat (str1, str2)
- char *str1, *str2;
+static const char * const backup_args[] =
{
- char *newstr;
- int str1_length = strlen (str1);
+ /* In a series of synonyms, present the most meaning full first, so
+ that argmatch_valid be more readable. */
+ "none", "off",
+ "simple", "never",
+ "existing", "nil",
+ "numbered", "t",
+ 0
+};
+
+static const enum backup_type backup_types[] =
+{
+ none, none,
+ simple, simple,
+ numbered_existing, numbered_existing,
+ numbered, numbered
+};
+
+/* Return the type of backup specified by VERSION.
+ If VERSION is NULL or the empty string, return numbered_existing.
+ If VERSION is invalid or ambiguous, fail with a diagnostic appropriate
+ for the specified CONTEXT. Unambiguous abbreviations are accepted. */
+
+enum backup_type
+get_version (const char *context, const char *version)
+{
+ if (version == 0 || *version == 0)
+ return numbered_existing;
+ else
+ return XARGMATCH (context, version, backup_args, backup_types);
+}
- newstr = malloc (str1_length + strlen (str2) + 1);
- if (newstr == 0)
- return 0;
- strcpy (newstr, str1);
- strcpy (newstr + str1_length, str2);
- return newstr;
+
+/* Return the type of backup specified by VERSION.
+ If VERSION is NULL, use the value of the envvar VERSION_CONTROL.
+ If the specified string is invalid or ambiguous, fail with a diagnostic
+ appropriate for the specified CONTEXT.
+ Unambiguous abbreviations are accepted. */
+
+enum backup_type
+xget_version (const char *context, const char *version)
+{
+ if (version && *version)
+ return get_version (context, version);
+ else
+ return get_version ("$VERSION_CONTROL", getenv ("VERSION_CONTROL"));
}