.

[gnulib.git] / lib / backupfile.c

diff --git a/lib/backupfile.c b/lib/backupfile.c
index 8222d46..2ca5125 100644 (file)
--- a/lib/backupfile.c
+++ b/lib/backupfile.c
@@ -12,8 +12,8 @@
    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; if not, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
 /* David MacKenzie <djm@gnu.ai.mit.edu>.
    Some algorithms adapted from GNU Emacs. */
@@ -63,13 +63,22 @@ char *malloc ();
 #endif
 
 #if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
-# define ISASCII(c) 1
+# define IN_CTYPE_DOMAIN(c) 1
 #else
-# define ISASCII(c) isascii(c)
+# define IN_CTYPE_DOMAIN(c) isascii(c)
 #endif
 
-#define ISDIGIT(c) (ISASCII ((unsigned char) (c)) \
-                   && isdigit ((unsigned char) (c)))
+#define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c))
+
+/* ISDIGIT differs from ISDIGIT_LOCALE, 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 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 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 (HAVE_UNISTD_H)
 #include <unistd.h>
@@ -105,7 +114,7 @@ static int version_number ();
 
 char *
 find_backup_file_name (file)
-     char *file;
+     const char *file;
 {
   char *dir;
   char *base_versions;
@@ -137,13 +146,14 @@ find_backup_file_name (file)
 
 static int
 max_backup_version (file, dir)
-     char *file, *dir;
+     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)
@@ -171,7 +181,7 @@ max_backup_version (file, dir)
 
 static char *
 make_version_name (file, version)
-     char *file;
+     const char *file;
      int version;
 {
   char *backup_name;
@@ -189,12 +199,12 @@ make_version_name (file, version)
 
 static int
 version_number (base, backup, base_length)
-     char *base;
-     char *backup;
+     const char *base;
+     const char *backup;
      int base_length;
 {
   int version;
-  char *p;
+  const char *p;
 
   version = 0;
   if (!strncmp (base, backup, base_length) && ISDIGIT (backup[base_length]))
@@ -212,7 +222,8 @@ version_number (base, backup, base_length)
 
 static char *
 concat (str1, str2)
-     char *str1, *str2;
+     const char *str1;
+     const char *str2;
 {
   char *newstr;
   int str1_length = strlen (str1);