-static size_t
-match_strings (const char *a, size_t a_len,
- const char *b, size_t b_len)
-{
- size_t match_len = 0;
-
- while (a_len > 0 && b_len > 0)
- {
- /* Mismatch always returns zero. */
- if (toupper ((unsigned char) *a++) != toupper ((unsigned char) *b++))
- return 0;
-
- /* Advance. */
- a_len--;
- b_len--;
- match_len++;
- }
-
- return match_len;
-}
-
-/* Returns the first character in the first word in STRING,
- storing the word's length in *WORD_LEN. If no words remain,
- returns a null pointer and stores 0 in *WORD_LEN. Words are
- sequences of alphanumeric characters or single
- non-alphanumeric characters. Words are delimited by
- spaces. */
-static const char *
-find_word (const char *string, size_t *word_len)
-{
- /* Skip whitespace and asterisks. */
- while (isspace ((unsigned char) *string))
- string++;
-
- /* End of string? */
- if (*string == '\0')
- {
- *word_len = 0;
- return NULL;
- }
-
- /* Special one-character word? */
- if (!isalnum ((unsigned char) *string))
- {
- *word_len = 1;
- return string;
- }
-
- /* Alphanumeric word. */
- *word_len = 1;
- while (isalnum ((unsigned char) string[*word_len]))
- (*word_len)++;
-
- return string;
-}
-
-/* Returns true if strings A and B can be confused based on
- their first three letters. */
-static bool
-conflicting_3char_prefixes (const char *a, const char *b)
-{
- size_t aw_len, bw_len;
- const char *aw, *bw;
-
- aw = find_word (a, &aw_len);
- bw = find_word (b, &bw_len);
- assert (aw != NULL && bw != NULL);
-
- /* Words that are the same don't conflict. */
- if (aw_len == bw_len && !buf_compare_case (aw, bw, aw_len))
- return false;
-
- /* Words that are otherwise the same in the first three letters
- do conflict. */
- return ((aw_len > 3 && bw_len > 3)
- || (aw_len == 3 && bw_len > 3)
- || (bw_len == 3 && aw_len > 3)) && !buf_compare_case (aw, bw, 3);
-}
-
-/* Returns true if CMD can be confused with another command
- based on the first three letters of its first word. */
-static bool
-conflicting_3char_prefix_command (const struct command *cmd)
-{
- assert (cmd >= commands && cmd < commands + command_cnt);
-
- return ((cmd > commands
- && conflicting_3char_prefixes (cmd[-1].name, cmd[0].name))
- || (cmd < commands + command_cnt
- && conflicting_3char_prefixes (cmd[0].name, cmd[1].name)));
-}
-
-/* Ways that a set of words can match a command name. */
-enum command_match
- {
- MISMATCH, /* Not a match. */
- PARTIAL_MATCH, /* The words begin the command name. */
- COMPLETE_MATCH /* The words are the command name. */
- };
-
-/* Figures out how well the WORD_CNT words in WORDS match CMD,
- and returns the appropriate enum value. If WORDS are a
- partial match for CMD and the next word in CMD is a dash, then
- *DASH_POSSIBLE is set to 1 if DASH_POSSIBLE is non-null;
- otherwise, *DASH_POSSIBLE is unchanged. */
-static enum command_match
-cmd_match_words (const struct command *cmd,
- char *const words[], size_t word_cnt,
- int *dash_possible)
-{
- const char *word;
- size_t word_len;
- size_t word_idx;
-
- for (word = find_word (cmd->name, &word_len), word_idx = 0;
- word != NULL && word_idx < word_cnt;
- word = find_word (word + word_len, &word_len), word_idx++)
- if (word_len != strlen (words[word_idx])
- || buf_compare_case (word, words[word_idx], word_len))
- {
- size_t match_chars = match_strings (word, word_len,
- words[word_idx],
- strlen (words[word_idx]));
- if (match_chars == 0)
- {
- /* Mismatch. */
- return MISMATCH;
- }
- else if (match_chars == 1 || match_chars == 2)
- {
- /* One- and two-character abbreviations are not
- acceptable. */
- return MISMATCH;
- }
- else if (match_chars == 3)
- {
- /* Three-character abbreviations are acceptable
- in the first word of a command if there are
- no name conflicts. They are always
- acceptable after the first word. */
- if (word_idx == 0 && conflicting_3char_prefix_command (cmd))
- return MISMATCH;
- }
- else /* match_chars > 3 */
- {
- /* Four-character and longer abbreviations are
- always acceptable. */
- }
- }
-
- if (word == NULL && word_idx == word_cnt)
- {
- /* cmd->name = "FOO BAR", words[] = {"FOO", "BAR"}. */
- return COMPLETE_MATCH;
- }
- else if (word == NULL)
- {
- /* cmd->name = "FOO BAR", words[] = {"FOO", "BAR", "BAZ"}. */
- return MISMATCH;
- }
- else
- {
- /* cmd->name = "FOO BAR BAZ", words[] = {"FOO", "BAR"}. */
- if (word[0] == '-' && dash_possible != NULL)
- *dash_possible = 1;
- return PARTIAL_MATCH;
- }
-}
-
-/* Returns the number of commands for which the WORD_CNT words in
- WORDS are a partial or complete match. If some partial match
- has a dash as the next word, then *DASH_POSSIBLE is set to 1,
- otherwise it is set to 0. */