This section describes the externally visible variables exported by
the GNU History Library.
Variable: inthistory_base
The logical offset of the first entry in the history list.
Variable: inthistory_length
The number of entries currently stored in the history list.
Variable: intmax_input_history
The maximum number of history entries. This must be changed using
stifle_history ().
Variable: charhistory_expansion_char
The character that starts a history event. The default is `!'.
Variable: charhistory_subst_char
The character that invokes word substitution if found at the start of
a line. The default is `^'.
Variable: charhistory_comment_char
During tokenization, if this character is seen as the first character
of a word, then it and all subsequent characters up to a newline are
ignored, suppressing history expansion for the remainder of the line.
This is disabled by default.
Variable: char*history_no_expand_chars
The list of characters which inhibit history expansion if found immediately
following history_expansion_char. The default is whitespace and
`='.
Variable: char*history_search_delimiter_chars
The list of additional characters which can delimit a history search
string, in addition to whitespace, `:' and `?' in the case of
a substring search. The default is empty.
Variable: inthistory_quotes_inhibit_expansion
If non-zero, single-quoted words are not scanned for the history expansion
character. The default value is 0.
This should be set to the address of a function that takes two arguments:
a char * (string) and an integer index into that string (i).
It should return a non-zero value if the history expansion starting at
string[i] should not be performed; zero if the expansion should
be done.
It is intended for use by applications like Bash that use the history
expansion character for additional purposes.
By default, this variable is set to NULL.