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diff --git a/readline/doc/hstech.texinfo b/readline/doc/hstech.texinfo deleted file mode 100644 index 9494446..0000000 --- a/readline/doc/hstech.texinfo +++ /dev/null @@ -1,550 +0,0 @@ -@ignore -This file documents the user interface to the GNU History library. - -Copyright (C) 1988-2002 Free Software Foundation, Inc. -Authored by Brian Fox and Chet Ramey. - -Permission is granted to make and distribute verbatim copies of this manual -provided the copyright notice and this permission notice are preserved on -all copies. - -Permission is granted to process this file through Tex and print the -results, provided the printed document carries copying permission notice -identical to this one except for the removal of this paragraph (this -paragraph not being relevant to the printed manual). - -Permission is granted to copy and distribute modified versions of this -manual under the conditions for verbatim copying, provided also that the -GNU Copyright statement is available to the distributee, and provided that -the entire resulting derived work is distributed under the terms of a -permission notice identical to this one. - -Permission is granted to copy and distribute translations of this manual -into another language, under the above conditions for modified versions. -@end ignore - -@node Programming with GNU History -@chapter Programming with GNU History - -This chapter describes how to interface programs that you write -with the @sc{gnu} History Library. -It should be considered a technical guide. -For information on the interactive use of @sc{gnu} History, @pxref{Using -History Interactively}. - -@menu -* Introduction to History:: What is the GNU History library for? -* History Storage:: How information is stored. -* History Functions:: Functions that you can use. -* History Variables:: Variables that control behaviour. -* History Programming Example:: Example of using the GNU History Library. -@end menu - -@node Introduction to History -@section Introduction to History - -Many programs read input from the user a line at a time. The @sc{gnu} -History library is able to keep track of those lines, associate arbitrary -data with each line, and utilize information from previous lines in -composing new ones. - -The programmer using the History library has available functions -for remembering lines on a history list, associating arbitrary data -with a line, removing lines from the list, searching through the list -for a line containing an arbitrary text string, and referencing any line -in the list directly. In addition, a history @dfn{expansion} function -is available which provides for a consistent user interface across -different programs. - -The user using programs written with the History library has the -benefit of a consistent user interface with a set of well-known -commands for manipulating the text of previous lines and using that text -in new commands. The basic history manipulation commands are similar to -the history substitution provided by @code{csh}. - -If the programmer desires, he can use the Readline library, which -includes some history manipulation by default, and has the added -advantage of command line editing. - -Before declaring any functions using any functionality the History -library provides in other code, an application writer should include -the file @code{<readline/history.h>} in any file that uses the -History library's features. It supplies extern declarations for all -of the library's public functions and variables, and declares all of -the public data structures. - -@node History Storage -@section History Storage - -The history list is an array of history entries. A history entry is -declared as follows: - -@example -typedef void *histdata_t; - -typedef struct _hist_entry @{ - char *line; - histdata_t data; -@} HIST_ENTRY; -@end example - -The history list itself might therefore be declared as - -@example -HIST_ENTRY **the_history_list; -@end example - -The state of the History library is encapsulated into a single structure: - -@example -/* - * A structure used to pass around the current state of the history. - */ -typedef struct _hist_state @{ - HIST_ENTRY **entries; /* Pointer to the entries themselves. */ - int offset; /* The location pointer within this array. */ - int length; /* Number of elements within this array. */ - int size; /* Number of slots allocated to this array. */ - int flags; -@} HISTORY_STATE; -@end example - -If the flags member includes @code{HS_STIFLED}, the history has been -stifled. - -@node History Functions -@section History Functions - -This section describes the calling sequence for the various functions -exported by the @sc{gnu} History library. - -@menu -* Initializing History and State Management:: Functions to call when you - want to use history in a - program. -* History List Management:: Functions used to manage the list - of history entries. -* Information About the History List:: Functions returning information about - the history list. -* Moving Around the History List:: Functions used to change the position - in the history list. -* Searching the History List:: Functions to search the history list - for entries containing a string. -* Managing the History File:: Functions that read and write a file - containing the history list. -* History Expansion:: Functions to perform csh-like history - expansion. -@end menu - -@node Initializing History and State Management -@subsection Initializing History and State Management - -This section describes functions used to initialize and manage -the state of the History library when you want to use the history -functions in your program. - -@deftypefun void using_history (void) -Begin a session in which the history functions might be used. This -initializes the interactive variables. -@end deftypefun - -@deftypefun {HISTORY_STATE *} history_get_history_state (void) -Return a structure describing the current state of the input history. -@end deftypefun - -@deftypefun void history_set_history_state (HISTORY_STATE *state) -Set the state of the history list according to @var{state}. -@end deftypefun - -@node History List Management -@subsection History List Management - -These functions manage individual entries on the history list, or set -parameters managing the list itself. - -@deftypefun void add_history (const char *string) -Place @var{string} at the end of the history list. The associated data -field (if any) is set to @code{NULL}. -@end deftypefun - -@deftypefun {HIST_ENTRY *} remove_history (int which) -Remove history entry at offset @var{which} from the history. The -removed element is returned so you can free the line, data, -and containing structure. -@end deftypefun - -@deftypefun {HIST_ENTRY *} replace_history_entry (int which, const char *line, histdata_t data) -Make the history entry at offset @var{which} have @var{line} and @var{data}. -This returns the old entry so you can dispose of the data. In the case -of an invalid @var{which}, a @code{NULL} pointer is returned. -@end deftypefun - -@deftypefun void clear_history (void) -Clear the history list by deleting all the entries. -@end deftypefun - -@deftypefun void stifle_history (int max) -Stifle the history list, remembering only the last @var{max} entries. -@end deftypefun - -@deftypefun int unstifle_history (void) -Stop stifling the history. This returns the previously-set -maximum number of history entries (as set by @code{stifle_history()}). -The value is positive if the history was -stifled, negative if it wasn't. -@end deftypefun - -@deftypefun int history_is_stifled (void) -Returns non-zero if the history is stifled, zero if it is not. -@end deftypefun - -@node Information About the History List -@subsection Information About the History List - -These functions return information about the entire history list or -individual list entries. - -@deftypefun {HIST_ENTRY **} history_list (void) -Return a @code{NULL} terminated array of @code{HIST_ENTRY *} which is the -current input history. Element 0 of this list is the beginning of time. -If there is no history, return @code{NULL}. -@end deftypefun - -@deftypefun int where_history (void) -Returns the offset of the current history element. -@end deftypefun - -@deftypefun {HIST_ENTRY *} current_history (void) -Return the history entry at the current position, as determined by -@code{where_history()}. If there is no entry there, return a @code{NULL} -pointer. -@end deftypefun - -@deftypefun {HIST_ENTRY *} history_get (int offset) -Return the history entry at position @var{offset}, starting from -@code{history_base} (@pxref{History Variables}). -If there is no entry there, or if @var{offset} -is greater than the history length, return a @code{NULL} pointer. -@end deftypefun - -@deftypefun int history_total_bytes (void) -Return the number of bytes that the primary history entries are using. -This function returns the sum of the lengths of all the lines in the -history. -@end deftypefun - -@node Moving Around the History List -@subsection Moving Around the History List - -These functions allow the current index into the history list to be -set or changed. - -@deftypefun int history_set_pos (int pos) -Set the current history offset to @var{pos}, an absolute index -into the list. -Returns 1 on success, 0 if @var{pos} is less than zero or greater -than the number of history entries. -@end deftypefun - -@deftypefun {HIST_ENTRY *} previous_history (void) -Back up the current history offset to the previous history entry, and -return a pointer to that entry. If there is no previous entry, return -a @code{NULL} pointer. -@end deftypefun - -@deftypefun {HIST_ENTRY *} next_history (void) -Move the current history offset forward to the next history entry, and -return the a pointer to that entry. If there is no next entry, return -a @code{NULL} pointer. -@end deftypefun - -@node Searching the History List -@subsection Searching the History List -@cindex History Searching - -These functions allow searching of the history list for entries containing -a specific string. Searching may be performed both forward and backward -from the current history position. The search may be @dfn{anchored}, -meaning that the string must match at the beginning of the history entry. -@cindex anchored search - -@deftypefun int history_search (const char *string, int direction) -Search the history for @var{string}, starting at the current history offset. -If @var{direction} is less than 0, then the search is through -previous entries, otherwise through subsequent entries. -If @var{string} is found, then -the current history index is set to that history entry, and the value -returned is the offset in the line of the entry where -@var{string} was found. Otherwise, nothing is changed, and a -1 is -returned. -@end deftypefun - -@deftypefun int history_search_prefix (const char *string, int direction) -Search the history for @var{string}, starting at the current history -offset. The search is anchored: matching lines must begin with -@var{string}. If @var{direction} is less than 0, then the search is -through previous entries, otherwise through subsequent entries. -If @var{string} is found, then the -current history index is set to that entry, and the return value is 0. -Otherwise, nothing is changed, and a -1 is returned. -@end deftypefun - -@deftypefun int history_search_pos (const char *string, int direction, int pos) -Search for @var{string} in the history list, starting at @var{pos}, an -absolute index into the list. If @var{direction} is negative, the search -proceeds backward from @var{pos}, otherwise forward. Returns the absolute -index of the history element where @var{string} was found, or -1 otherwise. -@end deftypefun - -@node Managing the History File -@subsection Managing the History File - -The History library can read the history from and write it to a file. -This section documents the functions for managing a history file. - -@deftypefun int read_history (const char *filename) -Add the contents of @var{filename} to the history list, a line at a time. -If @var{filename} is @code{NULL}, then read from @file{~/.history}. -Returns 0 if successful, or @code{errno} if not. -@end deftypefun - -@deftypefun int read_history_range (const char *filename, int from, int to) -Read a range of lines from @var{filename}, adding them to the history list. -Start reading at line @var{from} and end at @var{to}. -If @var{from} is zero, start at the beginning. If @var{to} is less than -@var{from}, then read until the end of the file. If @var{filename} is -@code{NULL}, then read from @file{~/.history}. Returns 0 if successful, -or @code{errno} if not. -@end deftypefun - -@deftypefun int write_history (const char *filename) -Write the current history to @var{filename}, overwriting @var{filename} -if necessary. -If @var{filename} is @code{NULL}, then write the history list to -@file{~/.history}. -Returns 0 on success, or @code{errno} on a read or write error. -@end deftypefun - -@deftypefun int append_history (int nelements, const char *filename) -Append the last @var{nelements} of the history list to @var{filename}. -If @var{filename} is @code{NULL}, then append to @file{~/.history}. -Returns 0 on success, or @code{errno} on a read or write error. -@end deftypefun - -@deftypefun int history_truncate_file (const char *filename, int nlines) -Truncate the history file @var{filename}, leaving only the last -@var{nlines} lines. -If @var{filename} is @code{NULL}, then @file{~/.history} is truncated. -Returns 0 on success, or @code{errno} on failure. -@end deftypefun - -@node History Expansion -@subsection History Expansion - -These functions implement history expansion. - -@deftypefun int history_expand (char *string, char **output) -Expand @var{string}, placing the result into @var{output}, a pointer -to a string (@pxref{History Interaction}). Returns: -@table @code -@item 0 -If no expansions took place (or, if the only change in -the text was the removal of escape characters preceding the history expansion -character); -@item 1 -if expansions did take place; -@item -1 -if there was an error in expansion; -@item 2 -if the returned line should be displayed, but not executed, -as with the @code{:p} modifier (@pxref{Modifiers}). -@end table - -If an error ocurred in expansion, then @var{output} contains a descriptive -error message. -@end deftypefun - -@deftypefun {char *} get_history_event (const char *string, int *cindex, int qchar) -Returns the text of the history event beginning at @var{string} + -@var{*cindex}. @var{*cindex} is modified to point to after the event -specifier. At function entry, @var{cindex} points to the index into -@var{string} where the history event specification begins. @var{qchar} -is a character that is allowed to end the event specification in addition -to the ``normal'' terminating characters. -@end deftypefun - -@deftypefun {char **} history_tokenize (const char *string) -Return an array of tokens parsed out of @var{string}, much as the -shell might. The tokens are split on the characters in the -@var{history_word_delimiters} variable, -and shell quoting conventions are obeyed. -@end deftypefun - -@deftypefun {char *} history_arg_extract (int first, int last, const char *string) -Extract a string segment consisting of the @var{first} through @var{last} -arguments present in @var{string}. Arguments are split using -@code{history_tokenize}. -@end deftypefun - -@node History Variables -@section History Variables - -This section describes the externally-visible variables exported by -the @sc{gnu} History Library. - -@deftypevar int history_base -The logical offset of the first entry in the history list. -@end deftypevar - -@deftypevar int history_length -The number of entries currently stored in the history list. -@end deftypevar - -@deftypevar int history_max_entries -The maximum number of history entries. This must be changed using -@code{stifle_history()}. -@end deftypevar - -@deftypevar char history_expansion_char -The character that introduces a history event. The default is @samp{!}. -Setting this to 0 inhibits history expansion. -@end deftypevar - -@deftypevar char history_subst_char -The character that invokes word substitution if found at the start of -a line. The default is @samp{^}. -@end deftypevar - -@deftypevar char history_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. -@end deftypevar - -@deftypevar {char *} history_word_delimiters -The characters that separate tokens for @code{history_tokenize()}. -The default value is @code{" \t\n()<>;&|"}. -@end deftypevar - -@deftypevar {char *} history_no_expand_chars -The list of characters which inhibit history expansion if found immediately -following @var{history_expansion_char}. The default is space, tab, newline, -carriage return, and @samp{=}. -@end deftypevar - -@deftypevar {char *} history_search_delimiter_chars -The list of additional characters which can delimit a history search -string, in addition to space, TAB, @samp{:} and @samp{?} in the case of -a substring search. The default is empty. -@end deftypevar - -@deftypevar int history_quotes_inhibit_expansion -If non-zero, single-quoted words are not scanned for the history expansion -character. The default value is 0. -@end deftypevar - -@deftypevar {rl_linebuf_func_t *} history_inhibit_expansion_function -This should be set to the address of a function that takes two arguments: -a @code{char *} (@var{string}) -and an @code{int} index into that string (@var{i}). -It should return a non-zero value if the history expansion starting at -@var{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 @code{NULL}. -@end deftypevar - -@node History Programming Example -@section History Programming Example - -The following program demonstrates simple use of the @sc{gnu} History Library. - -@smallexample -#include <stdio.h> -#include <readline/history.h> - -main (argc, argv) - int argc; - char **argv; -@{ - char line[1024], *t; - int len, done = 0; - - line[0] = 0; - - using_history (); - while (!done) - @{ - printf ("history$ "); - fflush (stdout); - t = fgets (line, sizeof (line) - 1, stdin); - if (t && *t) - @{ - len = strlen (t); - if (t[len - 1] == '\n') - t[len - 1] = '\0'; - @} - - if (!t) - strcpy (line, "quit"); - - if (line[0]) - @{ - char *expansion; - int result; - - result = history_expand (line, &expansion); - if (result) - fprintf (stderr, "%s\n", expansion); - - if (result < 0 || result == 2) - @{ - free (expansion); - continue; - @} - - add_history (expansion); - strncpy (line, expansion, sizeof (line) - 1); - free (expansion); - @} - - if (strcmp (line, "quit") == 0) - done = 1; - else if (strcmp (line, "save") == 0) - write_history ("history_file"); - else if (strcmp (line, "read") == 0) - read_history ("history_file"); - else if (strcmp (line, "list") == 0) - @{ - register HIST_ENTRY **the_list; - register int i; - - the_list = history_list (); - if (the_list) - for (i = 0; the_list[i]; i++) - printf ("%d: %s\n", i + history_base, the_list[i]->line); - @} - else if (strncmp (line, "delete", 6) == 0) - @{ - int which; - if ((sscanf (line + 6, "%d", &which)) == 1) - @{ - HIST_ENTRY *entry = remove_history (which); - if (!entry) - fprintf (stderr, "No such entry %d\n", which); - else - @{ - free (entry->line); - free (entry); - @} - @} - else - @{ - fprintf (stderr, "non-numeric arg given to `delete'\n"); - @} - @} - @} -@} -@end smallexample |