history: History Variables
1
1 2.4 History Variables
1 =====================
1
1 This section describes the externally-visible variables exported by the
1 GNU History Library.
1
1 -- Variable: int history_base
1 The logical offset of the first entry in the history list.
1
1 -- Variable: int history_length
1 The number of entries currently stored in the history list.
1
1 -- Variable: int history_max_entries
1 The maximum number of history entries. This must be changed using
1 'stifle_history()'.
1
1 -- Variable: int history_write_timestamps
1 If non-zero, timestamps are written to the history file, so they
1 can be preserved between sessions. The default value is 0, meaning
1 that timestamps are not saved.
1
1 The current timestamp format uses the value of HISTORY_COMMENT_CHAR
1 to delimit timestamp entries in the history file. If that variable
1 does not have a value (the default), timestamps will not be
1 written.
1
1 -- Variable: char history_expansion_char
1 The character that introduces a history event. The default is '!'.
1 Setting this to 0 inhibits history expansion.
1
1 -- Variable: char history_subst_char
1 The character that invokes word substitution if found at the start
1 of a line. The default is '^'.
1
1 -- Variable: char history_comment_char
1 During tokenization, if this character is seen as the first
1 character of a word, then it and all subsequent characters up to a
1 newline are ignored, suppressing history expansion for the
1 remainder of the line. This is disabled by default.
1
1 -- Variable: char * history_word_delimiters
1 The characters that separate tokens for 'history_tokenize()'. The
1 default value is '" \t\n()<>;&|"'.
1
1 -- Variable: char * history_search_delimiter_chars
1 The list of additional characters which can delimit a history
1 search string, in addition to space, TAB, ':' and '?' in the case
1 of a substring search. The default is empty.
1
1 -- Variable: char * history_no_expand_chars
1 The list of characters which inhibit history expansion if found
1 immediately following HISTORY_EXPANSION_CHAR. The default is
1 space, tab, newline, carriage return, and '='.
1
1 -- Variable: int history_quotes_inhibit_expansion
1 If non-zero, double-quoted words are not scanned for the history
1 expansion character or the history comment character. The default
1 value is 0.
1
1 -- Variable: rl_linebuf_func_t * history_inhibit_expansion_function
1 This should be set to the address of a function that takes two
1 arguments: a 'char *' (STRING) and an 'int' index into that string
1 (I). It should return a non-zero value if the history expansion
1 starting at STRING[I] should not be performed; zero if the
1 expansion should be done. It is intended for use by applications
1 like Bash that use the history expansion character for additional
1 purposes. By default, this variable is set to 'NULL'.
1