Add copyright notice.

[gnulib.git] / lib / backupfile.c

diff --git a/lib/backupfile.c b/lib/backupfile.c
index c20337a..7f4da17 100644 (file)
--- a/lib/backupfile.c
+++ b/lib/backupfile.c
@@ -1,5 +1,5 @@
 /* backupfile.c -- make Emacs style backup file names
-   Copyright (C) 1990-1997, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1990-1997, 1998, 1999 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
@@ -64,6 +64,12 @@
 char *malloc ();
 #endif
 
+#ifndef HAVE_DECL_GETENV
+char *getenv ();
+#endif
+
+char *base_name PARAMS ((char const *));
+
 #if HAVE_DIRENT_H || HAVE_NDIR_H || HAVE_SYS_DIR_H || HAVE_SYS_NDIR_H
 # define HAVE_DIR 1
 #else
@@ -97,18 +103,6 @@ char *malloc ();
 # define REAL_DIR_ENTRY(dp) 1
 #endif
 
-/* The following test is to work around the gross typo in
-   systems like Sony NEWS-OS Release 4.0C, whereby EXIT_FAILURE
-   is defined to 0, not 1.  */
-#if !EXIT_FAILURE
-# undef EXIT_FAILURE
-# define EXIT_FAILURE 1
-#endif
-
-#ifndef BACKUPFILE_EXIT_FAILURE
-# define BACKUPFILE_EXIT_FAILURE EXIT_FAILURE
-#endif
-
 /* The extension added to file names to produce a simple (as opposed
    to numbered) backup file name. */
 const char *simple_backup_suffix = "~";
@@ -224,31 +218,51 @@ version_number (const char *base, const char *backup, size_t base_length)
 }
 #endif /* HAVE_DIR */
 
-static const char *const backup_args[] =
+static const char * const backup_args[] =
 {
-  "never", "simple", "nil", "existing", "t", "numbered", 0
+  /* 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[] =
 {
-  simple, simple, numbered_existing, numbered_existing, numbered, numbered
+  none, none,
+  simple, simple,
+  numbered_existing, numbered_existing,
+  numbered, numbered
 };
 
-/* Return the type of backup indicated by VERSION.
-   Unique abbreviations are accepted. */
+/* 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 *version)
+get_version (const char *context, const char *version)
 {
-  int i;
-
   if (version == 0 || *version == 0)
     return numbered_existing;
-  i = argmatch (version, backup_args);
-  if (i < 0)
-    {
-      invalid_arg ("version control type", version, i);
-      exit (BACKUPFILE_EXIT_FAILURE);
-    }
-  return backup_types[i];
+  else
+    return XARGMATCH (context, version, backup_args, backup_types);
+}
+
+
+/* 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"));
 }