/**************************************************************************
* history.c -- This file is part of GNU nano. *
* *
* Copyright (C) 2003-2011, 2013-2018 Free Software Foundation, Inc. *
* Copyright (C) 2016-2017 Benno Schulenberg *
* *
* GNU nano is free software: you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published *
* by the Free Software Foundation, either version 3 of the License, *
* or (at your option) any later version. *
* *
* GNU nano is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty *
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *
* See the GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see http://www.gnu.org/licenses/. *
* *
**************************************************************************/
#include "proto.h"
#include <errno.h>
#include <string.h>
#ifdef ENABLE_HISTORIES
#ifndef SEARCH_HISTORY
#define SEARCH_HISTORY "search_history"
#endif
#ifndef POSITION_HISTORY
#define POSITION_HISTORY "filepos_history"
#endif
static bool history_changed = FALSE;
/* Whether any of the history lists has changed. */
static struct stat stat_of_positions_file;
/* The last-obtained stat information of the positions file. */
static char *poshistname = NULL;
/* The name of the positions-history file. */
/* Initialize the lists of historical search and replace strings
* and the list of historical executed commands. */
void history_init(void)
{
search_history = make_new_node(NULL);
search_history->data = mallocstrcpy(NULL, "");
searchtop = search_history;
searchbot = search_history;
replace_history = make_new_node(NULL);
replace_history->data = mallocstrcpy(NULL, "");
replacetop = replace_history;
replacebot = replace_history;
execute_history = make_new_node(NULL);
execute_history->data = mallocstrcpy(NULL, "");
executetop = execute_history;
executebot = execute_history;
}
/* Set the current position in the given history list to the bottom. */
void history_reset(const filestruct *list)
{
if (list == search_history)
search_history = searchbot;
else if (list == replace_history)
replace_history = replacebot;
else if (list == execute_history)
execute_history = executebot;
}
/* Return from the history list that starts at start and ends at end
* the first node that contains the first len characters of the given
* text, or NULL if there is no such node. */
filestruct *find_history(const filestruct *start, const filestruct *end,
const char *text, size_t len)
{
const filestruct *item;
for (item = start; item != end->prev && item != NULL; item = item->prev) {
if (strncmp(item->data, text, len) == 0)
return (filestruct *)item;
}
return NULL;
}
/* Update a history list (the one in which item is the current position)
* with a fresh string text. That is: add text, or move it to the end. */
void update_history(filestruct **item, const char *text)
{
filestruct **htop = NULL, **hbot = NULL, *thesame;
if (*item == search_history) {
htop = &searchtop;
hbot = &searchbot;
} else if (*item == replace_history) {
htop = &replacetop;
hbot = &replacebot;
} else if (*item == execute_history) {
htop = &executetop;
hbot = &executebot;
}
/* See if the string is already in the history. */
thesame = find_history(*hbot, *htop, text, HIGHEST_POSITIVE);
/* If an identical string was found, delete that item. */
if (thesame != NULL) {
filestruct *after = thesame->next;
/* If the string is at the head of the list, move the head. */
if (thesame == *htop)
*htop = after;
unlink_node(thesame);
renumber(after);
}
/* If the history is full, delete the oldest item (the one at the
* head of the list), to make room for a new item at the end. */
if ((*hbot)->lineno == MAX_SEARCH_HISTORY + 1) {
filestruct *oldest = *htop;
*htop = (*htop)->next;
unlink_node(oldest);
renumber(*htop);
}
/* Store the fresh string in the last item, then create a new item. */
(*hbot)->data = mallocstrcpy((*hbot)->data, text);
splice_node(*hbot, make_new_node(*hbot));
*hbot = (*hbot)->next;
(*hbot)->data = mallocstrcpy(NULL, "");
/* Indicate that the history needs to be saved on exit. */
history_changed = TRUE;
/* Set the current position in the list to the bottom. */
*item = *hbot;
}
/* Move h to the string in the history list just before it, and return
* that string. If there isn't one, don't move h and return NULL. */
char *get_history_older(filestruct **h)
{
if ((*h)->prev == NULL)
return NULL;
*h = (*h)->prev;
return (*h)->data;
}
/* Move h to the string in the history list just after it, and return
* that string. If there isn't one, don't move h and return NULL. */
char *get_history_newer(filestruct **h)
{
if ((*h)->next == NULL)
return NULL;
*h = (*h)->next;
return (*h)->data;
}
/* More placeholders. */
void get_history_newer_void(void)
{
;
}
void get_history_older_void(void)
{
;
}
#ifdef ENABLE_TABCOMP
/* Move h to the next string that's a tab completion of the string s,
* looking at only the first len characters of s, and return that
* string. If there isn't one, or if len is 0, don't move h and return
* s. */
char *get_history_completion(filestruct **h, char *s, size_t len)
{
if (len > 0) {
filestruct *htop = NULL, *hbot = NULL, *p;
if (*h == search_history) {
htop = searchtop;
hbot = searchbot;
} else if (*h == replace_history) {
htop = replacetop;
hbot = replacebot;
} else if (*h == execute_history) {
htop = executetop;
hbot = executebot;
}
/* Search the history list from the current position to the top
* for a match of len characters. Skip over an exact match. */
p = find_history((*h)->prev, htop, s, len);
while (p != NULL && strcmp(p->data, s) == 0)
p = find_history(p->prev, htop, s, len);
if (p != NULL) {
*h = p;
return mallocstrcpy(s, (*h)->data);
}
/* Search the history list from the bottom to the current position
* for a match of len characters. Skip over an exact match. */
p = find_history(hbot, *h, s, len);
while (p != NULL && strcmp(p->data, s) == 0)
p = find_history(p->prev, *h, s, len);
if (p != NULL) {
*h = p;
return mallocstrcpy(s, (*h)->data);
}
}
/* If we're here, we didn't find a match, we didn't find an inexact
* match, or len is 0. Return s. */
return (char *)s;
}
#endif /* ENABLE_TABCOMP */
void history_error(const char *msg, ...)
{
va_list ap;
va_start(ap, msg);
vfprintf(stderr, _(msg), ap);
va_end(ap);
fprintf(stderr, _("\nPress Enter to continue\n"));
while (getchar() != '\n')
;
}
/* Check whether we have or could make a directory for history files. */
bool have_statedir(void)
{
struct stat dirstat;
const char *xdgdatadir;
get_homedir();
if (homedir != NULL) {
statedir = concatenate(homedir, "/.nano/");
if (stat(statedir, &dirstat) == 0 && S_ISDIR(dirstat.st_mode)) {
poshistname = concatenate(statedir, POSITION_HISTORY);
return TRUE;
}
}
free(statedir);
xdgdatadir = getenv("XDG_DATA_HOME");
if (homedir == NULL && xdgdatadir == NULL)
return FALSE;
if (xdgdatadir != NULL)
statedir = concatenate(xdgdatadir, "/nano/");
else
statedir = concatenate(homedir, "/.local/share/nano/");
if (stat(statedir, &dirstat) == -1) {
if (xdgdatadir == NULL) {
char *statepath = concatenate(homedir, "/.local");
mkdir(statepath, S_IRWXU | S_IRWXG | S_IRWXO);
free(statepath);
statepath = concatenate(homedir, "/.local/share");
mkdir(statepath, S_IRWXU);
free(statepath);
}
if (mkdir(statedir, S_IRWXU) == -1) {
history_error(N_("Unable to create directory %s: %s\n"
"It is required for saving/loading "
"search history or cursor positions.\n"),
statedir, strerror(errno));
return FALSE;
}
} else if (!S_ISDIR(dirstat.st_mode)) {
history_error(N_("Path %s is not a directory and needs to be.\n"
"Nano will be unable to load or save "
"search history or cursor positions.\n"),
statedir);
return FALSE;
}
poshistname = concatenate(statedir, POSITION_HISTORY);
return TRUE;
}
/* Load the histories for Search and Replace and Execute Command. */
void load_history(void)
{
char *histname = concatenate(statedir, SEARCH_HISTORY);
FILE *hisfile = fopen(histname, "rb");
if (hisfile == NULL) {
if (errno != ENOENT) {
/* When reading failed, don't save history when we quit. */
UNSET(HISTORYLOG);
history_error(N_("Error reading %s: %s"), histname,
strerror(errno));
}
} else {
/* Load the three history lists -- first search, then replace,
* then execute -- from oldest entry to newest. Between two
* lists there is an empty line. */
filestruct **history = &search_history;
char *line = NULL;
size_t buf_len = 0;
ssize_t read;
while ((read = getline(&line, &buf_len, hisfile)) > 0) {
line[--read] = '\0';
if (read > 0) {
/* Encode any embedded NUL as 0x0A. */
unsunder(line, read);
update_history(history, line);
} else if (history == &search_history)
history = &replace_history;
else
history = &execute_history;
}
fclose(hisfile);
free(line);
}
/* After reading them in, set the status of the lists to "unchanged". */
history_changed = FALSE;
free(histname);
}
/* Write the lines of a history list, starting at head, from oldest to newest,
* to the given file. Return TRUE if writing succeeded, and FALSE otherwise. */
bool write_list(const filestruct *head, FILE *hisfile)
{
const filestruct *item;
for (item = head; item != NULL; item = item->next) {
size_t length = strlen(item->data);
/* Decode 0x0A bytes as embedded NULs. */
sunder(item->data);
if (fwrite(item->data, sizeof(char), length, hisfile) < length)
return FALSE;
if (putc('\n', hisfile) == EOF)
return FALSE;
}
return TRUE;
}
/* Save the histories for Search and Replace and Execute Command. */
void save_history(void)
{
char *histname;
FILE *hisfile;
/* If the histories are unchanged, don't bother saving them. */
if (!history_changed)
return;
histname = concatenate(statedir, SEARCH_HISTORY);
hisfile = fopen(histname, "wb");
if (hisfile == NULL)
fprintf(stderr, _("Error writing %s: %s\n"), histname,
strerror(errno));
else {
/* Don't allow others to read or write the history file. */
chmod(histname, S_IRUSR | S_IWUSR);
if (!write_list(searchtop, hisfile) ||
!write_list(replacetop, hisfile) ||
!write_list(executetop, hisfile))
fprintf(stderr, _("Error writing %s: %s\n"), histname,
strerror(errno));
fclose(hisfile);
}
free(histname);
}
/* Load the recorded cursor positions for files that were edited. */
void load_poshistory(void)
{
FILE *hisfile = fopen(poshistname, "rb");
if (hisfile == NULL) {
if (errno != ENOENT) {
/* When reading failed, don't save history when we quit. */
UNSET(POS_HISTORY);
history_error(N_("Error reading %s: %s"), poshistname, strerror(errno));
}
} else {
char *line = NULL, *lineptr, *xptr;
size_t buf_len = 0;
ssize_t read, count = 0;
poshiststruct *record_ptr = NULL, *newrecord;
/* Read and parse each line, and store the extracted data. */
while ((read = getline(&line, &buf_len, hisfile)) > 5) {
/* Decode nulls as embedded newlines. */
unsunder(line, read);
/* Find where the x index and line number are in the line. */
xptr = revstrstr(line, " ", line + read - 3);
if (xptr == NULL)
continue;
lineptr = revstrstr(line, " ", xptr - 2);
if (lineptr == NULL)
continue;
/* Now separate the three elements of the line. */
*(xptr++) = '\0';
*(lineptr++) = '\0';
/* Create a new position record. */
newrecord = (poshiststruct *)nmalloc(sizeof(poshiststruct));
newrecord->filename = mallocstrcpy(NULL, line);
newrecord->lineno = atoi(lineptr);
newrecord->xno = atoi(xptr);
newrecord->next = NULL;
/* Add the record to the list. */
if (position_history == NULL)
position_history = newrecord;
else
record_ptr->next = newrecord;
record_ptr = newrecord;
/* Impose a limit, so the file will not grow indefinitely. */
if (++count > 200) {
poshiststruct *drop_record = position_history;
position_history = position_history->next;
free(drop_record->filename);
free(drop_record);
}
}
fclose(hisfile);
free(line);
stat(poshistname, &stat_of_positions_file);
}
}
/* Save the recorded cursor positions for files that were edited. */
void save_poshistory(void)
{
poshiststruct *posptr;
FILE *hisfile = fopen(poshistname, "wb");
if (hisfile == NULL)
fprintf(stderr, _("Error writing %s: %s\n"), poshistname, strerror(errno));
else {
/* Don't allow others to read or write the history file. */
chmod(poshistname, S_IRUSR | S_IWUSR);
for (posptr = position_history; posptr != NULL; posptr = posptr->next) {
char *path_and_place;
size_t length;
/* Assume 20 decimal positions each for line and column number,
* plus two spaces, plus the line feed, plus the null byte. */
path_and_place = charalloc(strlen(posptr->filename) + 44);
sprintf(path_and_place, "%s %zd %zd\n",
posptr->filename, posptr->lineno, posptr->xno);
length = strlen(path_and_place);
/* Encode newlines in filenames as nulls. */
sunder(path_and_place);
/* Restore the terminating newline. */
path_and_place[length - 1] = '\n';
if (fwrite(path_and_place, sizeof(char), length, hisfile) < length)
fprintf(stderr, _("Error writing %s: %s\n"),
poshistname, strerror(errno));
free(path_and_place);
}
fclose(hisfile);
stat(poshistname, &stat_of_positions_file);
}
}
/* Reload the position history file if it has been modified since last load. */
void reload_positions_if_needed(void)
{
struct stat newstat;
stat(poshistname, &newstat);
if (newstat.st_mtime != stat_of_positions_file.st_mtime) {
poshiststruct *ptr, *nextone;
for (ptr = position_history; ptr != NULL; ptr = nextone) {
nextone = ptr->next;
free(ptr->filename);
free(ptr);
}
position_history = NULL;
load_poshistory();
}
}
/* Update the recorded last file positions, given a filename, a line
* and a column. If no entry is found, add a new one at the end. */
void update_poshistory(char *filename, ssize_t lineno, ssize_t xpos)
{
poshiststruct *posptr, *theone, *posprev = NULL;
char *fullpath = get_full_path(filename);
if (fullpath == NULL || fullpath[strlen(fullpath) - 1] == '/' || inhelp) {
free(fullpath);
return;
}
reload_positions_if_needed();
/* Look for a matching filename in the list. */
for (posptr = position_history; posptr != NULL; posptr = posptr->next) {
if (!strcmp(posptr->filename, fullpath))
break;
posprev = posptr;
}
/* Don't record files that have the default cursor position. */
if (lineno == 1 && xpos == 1) {
if (posptr != NULL) {
if (posprev == NULL)
position_history = posptr->next;
else
posprev->next = posptr->next;
free(posptr->filename);
free(posptr);
save_poshistory();
}
free(fullpath);
return;
}
theone = posptr;
/* If we didn't find it, make a new node; otherwise, if we're
* not at the end, move the matching one to the end. */
if (theone == NULL) {
theone = (poshiststruct *)nmalloc(sizeof(poshiststruct));
theone->filename = mallocstrcpy(NULL, fullpath);
if (position_history == NULL)
position_history = theone;
else
posprev->next = theone;
} else if (posptr->next != NULL) {
if (posprev == NULL)
position_history = posptr->next;
else
posprev->next = posptr->next;
while (posptr->next != NULL)
posptr = posptr->next;
posptr->next = theone;
}
/* Store the last cursor position. */
theone->lineno = lineno;
theone->xno = xpos;
theone->next = NULL;
free(fullpath);
save_poshistory();
}
/* Check whether the given file matches an existing entry in the recorded
* last file positions. If not, return FALSE. If yes, return TRUE and
* set line and column to the retrieved values. */
bool has_old_position(const char *file, ssize_t *line, ssize_t *column)
{
poshiststruct *posptr = position_history;
char *fullpath = get_full_path(file);
if (fullpath == NULL)
return FALSE;
reload_positions_if_needed();
while (posptr != NULL && strcmp(posptr->filename, fullpath) != 0)
posptr = posptr->next;
free(fullpath);
if (posptr == NULL)
return FALSE;
*line = posptr->lineno;
*column = posptr->xno;
return TRUE;
}
#endif /* ENABLE_HISTORIES */