history.c File Reference

Read/write command history from/to a file. More...

#include "config.h"
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "mutt/lib.h"
#include "config/lib.h"
#include "core/lib.h"
#include "lib.h"

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Data Structures
struct	History
	Saved list of user-entered commands/searches. More...

Macros
#define	HC_FIRST   HC_CMD

Functions
static struct History *	get_history (enum HistoryClass hclass)
	Get a particular history. More...
static void	init_history (struct History *h)
	Set up a new History ring buffer. More...
static int	dup_hash_dec (struct HashTable *dup_hash, char *str)
	Decrease the refcount of a history string. More...
static int	dup_hash_inc (struct HashTable *dup_hash, char *str)
	Increase the refcount of a history string. More...
static void	shrink_histfile (void)
	Read, de-dupe and write the history file. More...
static void	save_history (enum HistoryClass hclass, const char *str)
	Save one history string to a file. More...
static void	remove_history_dups (enum HistoryClass hclass, const char *str)
	De-dupe the history. More...
int	mutt_hist_search (const char *search_buf, enum HistoryClass hclass, char **matches)
	Find matches in a history list. More...
void	mutt_hist_free (void)
	Free all the history lists. More...
void	mutt_hist_init (void)
	Create a set of empty History ring buffers. More...
void	mutt_hist_add (enum HistoryClass hclass, const char *str, bool save)
	Add a string to a history. More...
char *	mutt_hist_next (enum HistoryClass hclass)
	Get the next string in a History. More...
char *	mutt_hist_prev (enum HistoryClass hclass)
	Get the previous string in a History. More...
void	mutt_hist_reset_state (enum HistoryClass hclass)
	Move the 'current' position to the end of the History. More...
void	mutt_hist_read_file (void)
	Read the History from a file. More...
bool	mutt_hist_at_scratch (enum HistoryClass hclass)
	Is the current History position at the 'scratch' place? More...
void	mutt_hist_save_scratch (enum HistoryClass hclass, const char *str)
	Save a temporary string to the History. More...

Variables
static struct History	Histories [HC_MAX]
	Command histories, one for each HistoryClass. More...
static int	OldSize = 0
	The previous number of history entries to save. More...

Detailed Description

Read/write command history from/to a file.

Authors

• Michael R. Elkins

Copyright

This program 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 2 of the License, or (at your option) any later version.

This program 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/.

Definition in file history.c.

Macro Definition Documentation

HC_FIRST

#define HC_FIRST   HC_CMD

Definition at line 81 of file history.c.

Function Documentation

get_history()

static struct History * get_history ( enum HistoryClass  hclass )

static

Get a particular history.

Parameters

hclass

Type of history to find

Return values

ptr	History ring buffer

Definition at line 108 of file history.c.

{
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  if ((hclass >= HC_MAX) || (c_history == 0))
    return NULL;
 
  struct History *hist = &Histories[hclass];
  return hist->hist ? hist : NULL;
}

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init_history()

static void init_history ( struct History *  h )

static

Set up a new History ring buffer.

Parameters

h	History to populate

If the History already has entries, they will be freed.

Definition at line 124 of file history.c.

{
  if (OldSize != 0)
  {
    if (h->hist)
    {
      for (int i = 0; i <= OldSize; i++)
        FREE(&h->hist[i]);
      FREE(&h->hist);
    }
  }
 
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  if (c_history != 0)
    h->hist = mutt_mem_calloc(c_history + 1, sizeof(char *));
 
  h->cur = 0;
  h->last = 0;
}

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dup_hash_dec()

static int dup_hash_dec ( struct HashTable *  dup_hash, char *  str  )

static

Decrease the refcount of a history string.

Parameters

dup_hash	Hash Table containing unique history strings
str	String to find

Return values

0	String was deleted from the Hash Table
>0	Refcount of string
-1	Error, string not found

If the string's refcount is 1, then the string will be deleted.

Definition at line 154 of file history.c.

{
  struct HashElem *he = mutt_hash_find_elem(dup_hash, str);
  if (!he)
    return -1;
 
  uintptr_t count = (uintptr_t) he->data;
  if (count <= 1)
  {
    mutt_hash_delete(dup_hash, str, NULL);
    return 0;
  }
 
  count--;
  he->data = (void *) count;
  return count;
}

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dup_hash_inc()

static int dup_hash_inc ( struct HashTable *  dup_hash, char *  str  )

static

Increase the refcount of a history string.

Parameters

dup_hash	Hash Table containing unique history strings
str	String to find

Return values

num	Refcount of string

If the string isn't found it will be added to the Hash Table.

Definition at line 180 of file history.c.

{
  uintptr_t count;
 
  struct HashElem *he = mutt_hash_find_elem(dup_hash, str);
  if (!he)
  {
    count = 1;
    mutt_hash_insert(dup_hash, str, (void *) count);
    return count;
  }
 
  count = (uintptr_t) he->data;
  count++;
  he->data = (void *) count;
  return count;
}

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shrink_histfile()

static void shrink_histfile ( void  )

static

Read, de-dupe and write the history file.

Definition at line 201 of file history.c.

{
  FILE *fp_tmp = NULL;
  int n[HC_MAX] = { 0 };
  int line, hclass, read;
  char *linebuf = NULL, *p = NULL;
  size_t buflen;
  bool regen_file = false;
  struct HashTable *dup_hashes[HC_MAX] = { 0 };
 
  const char *const c_history_file = cs_subset_path(NeoMutt->sub, "history_file");
  FILE *fp = mutt_file_fopen(c_history_file, "r");
  if (!fp)
    return;
 
  const bool c_history_remove_dups = cs_subset_bool(NeoMutt->sub, "history_remove_dups");
  const short c_save_history = cs_subset_number(NeoMutt->sub, "save_history");
  if (c_history_remove_dups)
  {
    for (hclass = 0; hclass < HC_MAX; hclass++)
      dup_hashes[hclass] = mutt_hash_new(MAX(10, c_save_history * 2), MUTT_HASH_STRDUP_KEYS);
  }
 
  line = 0;
  while ((linebuf = mutt_file_read_line(linebuf, &buflen, fp, &line, MUTT_RL_NO_FLAGS)))
  {
    if ((sscanf(linebuf, "%d:%n", &hclass, &read) < 1) || (read == 0) ||
        (*(p = linebuf + strlen(linebuf) - 1) != '|') || (hclass < 0))
    {
      mutt_error(_("Bad history file format (line %d)"), line);
      goto cleanup;
    }
    /* silently ignore too high class (probably newer neomutt) */
    if (hclass >= HC_MAX)
      continue;
    *p = '\0';
    if (c_history_remove_dups && (dup_hash_inc(dup_hashes[hclass], linebuf + read) > 1))
    {
      regen_file = true;
      continue;
    }
    n[hclass]++;
  }
 
  if (!regen_file)
  {
    for (hclass = HC_FIRST; hclass < HC_MAX; hclass++)
    {
      if (n[hclass] > c_save_history)
      {
        regen_file = true;
        break;
      }
    }
  }
 
  if (regen_file)
  {
    fp_tmp = mutt_file_mkstemp();
    if (!fp_tmp)
    {
      mutt_perror(_("Can't create temporary file"));
      goto cleanup;
    }
    rewind(fp);
    line = 0;
    while ((linebuf = mutt_file_read_line(linebuf, &buflen, fp, &line, MUTT_RL_NO_FLAGS)))
    {
      if ((sscanf(linebuf, "%d:%n", &hclass, &read) < 1) || (read == 0) ||
          (*(p = linebuf + strlen(linebuf) - 1) != '|') || (hclass < 0))
      {
        mutt_error(_("Bad history file format (line %d)"), line);
        goto cleanup;
      }
      if (hclass >= HC_MAX)
        continue;
      *p = '\0';
      if (c_history_remove_dups && (dup_hash_dec(dup_hashes[hclass], linebuf + read) > 0))
      {
        continue;
      }
      *p = '|';
      if (n[hclass]-- <= c_save_history)
        fprintf(fp_tmp, "%s\n", linebuf);
    }
  }
 
cleanup:
  mutt_file_fclose(&fp);
  FREE(&linebuf);
  if (fp_tmp)
  {
    if ((fflush(fp_tmp) == 0) && (fp = fopen(NONULL(c_history_file), "w")))
    {
      rewind(fp_tmp);
      mutt_file_copy_stream(fp_tmp, fp);
      mutt_file_fclose(&fp);
    }
    mutt_file_fclose(&fp_tmp);
  }
  if (c_history_remove_dups)
    for (hclass = 0; hclass < HC_MAX; hclass++)
      mutt_hash_free(&dup_hashes[hclass]);
}

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save_history()

static void save_history ( enum HistoryClass  hclass, const char *  str  )

static

Save one history string to a file.

Parameters

hclass	History type
str	String to save

Definition at line 311 of file history.c.

{
  static int n = 0;
  char *tmp = NULL;
 
  if (!str || (*str == '\0')) /* This shouldn't happen, but it's safer. */
    return;
 
  const char *const c_history_file = cs_subset_path(NeoMutt->sub, "history_file");
  FILE *fp = mutt_file_fopen(c_history_file, "a");
  if (!fp)
    return;
 
  tmp = mutt_str_dup(str);
  mutt_ch_convert_string(&tmp, cc_charset(), "utf-8", MUTT_ICONV_NO_FLAGS);
 
  /* Format of a history item (1 line): "<histclass>:<string>|".
   * We add a '|' in order to avoid lines ending with '\'. */
  fprintf(fp, "%d:", (int) hclass);
  for (char *p = tmp; *p; p++)
  {
    /* Don't copy \n as a history item must fit on one line. The string
     * shouldn't contain such a character anyway, but as this can happen
     * in practice, we must deal with that. */
    if (*p != '\n')
      putc((unsigned char) *p, fp);
  }
  fputs("|\n", fp);
 
  mutt_file_fclose(&fp);
  FREE(&tmp);
 
  if (--n < 0)
  {
    const short c_save_history = cs_subset_number(NeoMutt->sub, "save_history");
    n = c_save_history;
    shrink_histfile();
  }
}

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remove_history_dups()

static void remove_history_dups ( enum HistoryClass  hclass, const char *  str  )

static

De-dupe the history.

Parameters

hclass	History to de-dupe
str	String to find

If the string is found, it is removed from the history.

When removing dups, we want the created "blanks" to be right below the resulting h->last position. See the comment section above 'struct History'.

Definition at line 361 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return; /* disabled */
 
  /* Remove dups from 0..last-1 compacting up. */
  int source = 0;
  int dest = 0;
  while (source < h->last)
  {
    if (mutt_str_equal(h->hist[source], str))
      FREE(&h->hist[source++]);
    else
      h->hist[dest++] = h->hist[source++];
  }
 
  /* Move 'last' entry up. */
  h->hist[dest] = h->hist[source];
  int old_last = h->last;
  h->last = dest;
 
  /* Fill in moved entries with NULL */
  while (source > h->last)
    h->hist[source--] = NULL;
 
  /* Remove dups from last+1 .. `$history` compacting down. */
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  source = c_history;
  dest = c_history;
  while (source > old_last)
  {
    if (mutt_str_equal(h->hist[source], str))
      FREE(&h->hist[source--]);
    else
      h->hist[dest--] = h->hist[source--];
  }
 
  /* Fill in moved entries with NULL */
  while (dest > old_last)
    h->hist[dest--] = NULL;
}

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mutt_hist_search()

int mutt_hist_search	(	const char *	search_buf,
		enum HistoryClass	hclass,
		char **	matches
	)

Find matches in a history list.

Parameters

[in]	search_buf	String to find
[in]	hclass	History list
[out]	matches	All the matching lines

Return values

num	Matches found

Definition at line 411 of file history.c.

{
  if (!search_buf || !matches)
    return 0;
 
  struct History *h = get_history(hclass);
  if (!h)
    return 0;
 
  int match_count = 0;
  int cur = h->last;
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  do
  {
    cur--;
    if (cur < 0)
      cur = c_history;
    if (cur == h->last)
      break;
    if (mutt_istr_find(h->hist[cur], search_buf))
      matches[match_count++] = h->hist[cur];
  } while (match_count < c_history);
 
  return match_count;
}

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mutt_hist_free()

void mutt_hist_free

(

void

)

Free all the history lists.

Definition at line 440 of file history.c.

{
  if (!NeoMutt)
    return;
 
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  for (enum HistoryClass hclass = HC_FIRST; hclass < HC_MAX; hclass++)
  {
    struct History *h = &Histories[hclass];
    if (!h->hist)
      continue;
 
    /* The array has (`$history`+1) elements */
    for (int i = 0; i <= c_history; i++)
    {
      FREE(&h->hist[i]);
    }
    FREE(&h->hist);
  }
}

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mutt_hist_init()

void mutt_hist_init

(

void

)

Create a set of empty History ring buffers.

This just creates empty histories. To fill them, call mutt_hist_read_file().

Definition at line 467 of file history.c.

{
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  if (c_history == OldSize)
    return;
 
  for (enum HistoryClass hclass = HC_FIRST; hclass < HC_MAX; hclass++)
    init_history(&Histories[hclass]);
 
  OldSize = c_history;
}

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mutt_hist_add()

void mutt_hist_add	(	enum HistoryClass	hclass,
		const char *	str,
		bool	save
	)

Add a string to a history.

Parameters

hclass	History to add to
str	String to add
save	Should the changes be saved to file immediately?

Definition at line 485 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return; /* disabled */
 
  if (*str)
  {
    int prev = h->last - 1;
    const short c_history = cs_subset_number(NeoMutt->sub, "history");
    if (prev < 0)
      prev = c_history;
 
    /* don't add to prompt history:
     *  - lines beginning by a space
     *  - repeated lines */
    if ((*str != ' ') && (!h->hist[prev] || !mutt_str_equal(h->hist[prev], str)))
    {
      const bool c_history_remove_dups = cs_subset_bool(NeoMutt->sub, "history_remove_dups");
      if (c_history_remove_dups)
        remove_history_dups(hclass, str);
      const short c_save_history = cs_subset_number(NeoMutt->sub, "save_history");
      const char *const c_history_file = cs_subset_path(NeoMutt->sub, "history_file");
      if (save && (c_save_history != 0) && c_history_file)
        save_history(hclass, str);
      mutt_str_replace(&h->hist[h->last++], str);
      if (h->last > c_history)
        h->last = 0;
    }
  }
  h->cur = h->last; /* reset to the last entry */
}

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mutt_hist_next()

char * mutt_hist_next

(

enum HistoryClass

hclass

)

Get the next string in a History.

Parameters

hclass

History to choose

Return values

ptr	Next string

If there is no next string, and empty string will be returned.

Definition at line 525 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return ""; /* disabled */
 
  int next = h->cur;
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  do
  {
    next++;
    if (next > c_history)
      next = 0;
    if (next == h->last)
      break;
  } while (!h->hist[next]);
 
  h->cur = next;
  return NONULL(h->hist[h->cur]);
}

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mutt_hist_prev()

char * mutt_hist_prev

(

enum HistoryClass

hclass

)

Get the previous string in a History.

Parameters

hclass

History to choose

Return values

ptr	Previous string

If there is no previous string, and empty string will be returned.

Definition at line 553 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return ""; /* disabled */
 
  int prev = h->cur;
  const short c_history = cs_subset_number(NeoMutt->sub, "history");
  do
  {
    prev--;
    if (prev < 0)
      prev = c_history;
    if (prev == h->last)
      break;
  } while (!h->hist[prev]);
 
  h->cur = prev;
  return NONULL(h->hist[h->cur]);
}

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mutt_hist_reset_state()

void mutt_hist_reset_state

(

enum HistoryClass

hclass

)

Move the 'current' position to the end of the History.

Parameters

hclass

History to reset

After calling mutt_hist_next() and mutt_hist_prev(), this function resets the current position ('cur' pointer).

Definition at line 581 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return; /* disabled */
 
  h->cur = h->last;
}

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mutt_hist_read_file()

void mutt_hist_read_file

(

void

)

Read the History from a file.

The file $history_file is read and parsed into separate History ring buffers.

Definition at line 595 of file history.c.

{
  int line = 0, hclass, read;
  char *linebuf = NULL, *p = NULL;
  size_t buflen;
 
  const char *const c_history_file = cs_subset_path(NeoMutt->sub, "history_file");
  if (!c_history_file)
    return;
 
  FILE *fp = mutt_file_fopen(c_history_file, "r");
  if (!fp)
    return;
 
  const char *const c_charset = cc_charset();
  while ((linebuf = mutt_file_read_line(linebuf, &buflen, fp, &line, MUTT_RL_NO_FLAGS)))
  {
    read = 0;
    if ((sscanf(linebuf, "%d:%n", &hclass, &read) < 1) || (read == 0) ||
        (*(p = linebuf + strlen(linebuf) - 1) != '|') || (hclass < 0))
    {
      mutt_error(_("Bad history file format (line %d)"), line);
      break;
    }
    /* silently ignore too high class (probably newer neomutt) */
    if (hclass >= HC_MAX)
      continue;
    *p = '\0';
    p = mutt_str_dup(linebuf + read);
    if (p)
    {
      mutt_ch_convert_string(&p, "utf-8", c_charset, MUTT_ICONV_NO_FLAGS);
      mutt_hist_add(hclass, p, false);
      FREE(&p);
    }
  }
 
  mutt_file_fclose(&fp);
  FREE(&linebuf);
}

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mutt_hist_at_scratch()

bool mutt_hist_at_scratch

(

enum HistoryClass

hclass

)

Is the current History position at the 'scratch' place?

Parameters

hclass

History to use

Return values

true	History is at 'scratch' place

The last entry in the history is used as a 'scratch' area. It can be overwritten as the user types and edits.

To get (back) to the scratch area, call mutt_hist_next(), mutt_hist_prev() or mutt_hist_reset_state().

Definition at line 647 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return false; /* disabled */
 
  return h->cur == h->last;
}

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mutt_hist_save_scratch()

void mutt_hist_save_scratch	(	enum HistoryClass	hclass,
		const char *	str
	)

Save a temporary string to the History.

Parameters

hclass	History to alter
str	String to set

Write a 'scratch' string into the History's current position. This is useful to preserver a user's edits.

Definition at line 664 of file history.c.

{
  struct History *h = get_history(hclass);
  if (!h)
    return; /* disabled */
 
  /* Don't check if str has a value because the scratch buffer may contain
   * an old garbage value that should be overwritten */
  mutt_str_replace(&h->hist[h->last], str);
}

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Variable Documentation

Histories

struct History Histories[HC_MAX]

static

Command histories, one for each HistoryClass.

Definition at line 98 of file history.c.

OldSize

int OldSize = 0

static

The previous number of history entries to save.

See also

$history

Definition at line 101 of file history.c.