- int version;
- char *p;
-
- version = 0;
- if (!strncmp (base, backup, base_length) && ISDIGIT (backup[base_length]))
- {
- for (p = &backup[base_length]; ISDIGIT (*p); ++p)
- version = version * 10 + *p - '0';
- if (p[0] != '~' || p[1])
- version = 0;
- }
- return version;
+ /* 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[] =
+{
+ no_backups, no_backups,
+ simple_backups, simple_backups,
+ numbered_existing_backups, numbered_existing_backups,
+ numbered_backups, numbered_backups
+};
+
+/* Return the type of backup specified by VERSION.
+ If VERSION is NULL or the empty string, return numbered_existing_backups.
+ If VERSION is invalid or ambiguous, fail with a diagnostic appropriate
+ for the specified CONTEXT. Unambiguous abbreviations are accepted. */
+
+enum backup_type
+get_version (char const *context, char const *version)
+{
+ if (version == 0 || *version == 0)
+ return numbered_existing_backups;
+ else
+ return XARGMATCH (context, version, backup_args, backup_types);