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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 18:33:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 18:33:23 +0000
commit1d5cace9db9aef76f26b2d7ba54bbb76443b00b2 (patch)
tree314a15dd1aa103da13bdc83ba1d2105a290bc5ba /lib/readline/histfile.c
parentInitial commit. (diff)
downloadbash-1d5cace9db9aef76f26b2d7ba54bbb76443b00b2.tar.xz
bash-1d5cace9db9aef76f26b2d7ba54bbb76443b00b2.zip
Adding upstream version 5.0.upstream/5.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/readline/histfile.c')
-rw-r--r--lib/readline/histfile.c791
1 files changed, 791 insertions, 0 deletions
diff --git a/lib/readline/histfile.c b/lib/readline/histfile.c
new file mode 100644
index 0000000..dc64bde
--- /dev/null
+++ b/lib/readline/histfile.c
@@ -0,0 +1,791 @@
+/* histfile.c - functions to manipulate the history file. */
+
+/* Copyright (C) 1989-2018 Free Software Foundation, Inc.
+
+ This file contains the GNU History Library (History), a set of
+ routines for managing the text of previously typed lines.
+
+ History 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.
+
+ History 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 History. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* The goal is to make the implementation transparent, so that you
+ don't have to know what data types are used, just what functions
+ you can call. I think I have done that. */
+
+#define READLINE_LIBRARY
+
+#if defined (__TANDEM)
+# include <floss.h>
+#endif
+
+#if defined (HAVE_CONFIG_H)
+# include <config.h>
+#endif
+
+#include <stdio.h>
+
+#if defined (HAVE_LIMITS_H)
+# include <limits.h>
+#endif
+
+#include <sys/types.h>
+#if ! defined (_MINIX) && defined (HAVE_SYS_FILE_H)
+# include <sys/file.h>
+#endif
+#include "posixstat.h"
+#include <fcntl.h>
+
+#if defined (HAVE_STDLIB_H)
+# include <stdlib.h>
+#else
+# include "ansi_stdlib.h"
+#endif /* HAVE_STDLIB_H */
+
+#if defined (HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+
+#include <ctype.h>
+
+#if defined (__EMX__)
+# undef HAVE_MMAP
+#endif
+
+#ifdef HISTORY_USE_MMAP
+# include <sys/mman.h>
+
+# ifdef MAP_FILE
+# define MAP_RFLAGS (MAP_FILE|MAP_PRIVATE)
+# define MAP_WFLAGS (MAP_FILE|MAP_SHARED)
+# else
+# define MAP_RFLAGS MAP_PRIVATE
+# define MAP_WFLAGS MAP_SHARED
+# endif
+
+# ifndef MAP_FAILED
+# define MAP_FAILED ((void *)-1)
+# endif
+
+#endif /* HISTORY_USE_MMAP */
+
+/* If we're compiling for __EMX__ (OS/2) or __CYGWIN__ (cygwin32 environment
+ on win 95/98/nt), we want to open files with O_BINARY mode so that there
+ is no \n -> \r\n conversion performed. On other systems, we don't want to
+ mess around with O_BINARY at all, so we ensure that it's defined to 0. */
+#if defined (__EMX__) || defined (__CYGWIN__)
+# ifndef O_BINARY
+# define O_BINARY 0
+# endif
+#else /* !__EMX__ && !__CYGWIN__ */
+# undef O_BINARY
+# define O_BINARY 0
+#endif /* !__EMX__ && !__CYGWIN__ */
+
+#include <errno.h>
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+#include "history.h"
+#include "histlib.h"
+
+#include "rlshell.h"
+#include "xmalloc.h"
+
+#if !defined (PATH_MAX)
+# define PATH_MAX 1024 /* default */
+#endif
+
+extern void _hs_append_history_line PARAMS((int, const char *));
+
+/* history file version; currently unused */
+int history_file_version = 1;
+
+/* If non-zero, we write timestamps to the history file in history_do_write() */
+int history_write_timestamps = 0;
+
+/* If non-zero, we assume that a history file that starts with a timestamp
+ uses timestamp-delimited entries and can include multi-line history
+ entries. Used by read_history_range */
+int history_multiline_entries = 0;
+
+/* Immediately after a call to read_history() or read_history_range(), this
+ will return the number of lines just read from the history file in that
+ call. */
+int history_lines_read_from_file = 0;
+
+/* Immediately after a call to write_history() or history_do_write(), this
+ will return the number of lines just written to the history file in that
+ call. This also works with history_truncate_file. */
+int history_lines_written_to_file = 0;
+
+/* Does S look like the beginning of a history timestamp entry? Placeholder
+ for more extensive tests. */
+#define HIST_TIMESTAMP_START(s) (*(s) == history_comment_char && isdigit ((unsigned char)(s)[1]) )
+
+static char *history_backupfile PARAMS((const char *));
+static char *history_tempfile PARAMS((const char *));
+static int histfile_backup PARAMS((const char *, const char *));
+static int histfile_restore PARAMS((const char *, const char *));
+
+/* Return the string that should be used in the place of this
+ filename. This only matters when you don't specify the
+ filename to read_history (), or write_history (). */
+static char *
+history_filename (const char *filename)
+{
+ char *return_val;
+ const char *home;
+ int home_len;
+
+ return_val = filename ? savestring (filename) : (char *)NULL;
+
+ if (return_val)
+ return (return_val);
+
+ home = sh_get_env_value ("HOME");
+#if defined (_WIN32)
+ if (home == 0)
+ home = sh_get_env_value ("APPDATA");
+#endif
+
+ if (home == 0)
+ return (NULL);
+ else
+ home_len = strlen (home);
+
+ return_val = (char *)xmalloc (2 + home_len + 8); /* strlen(".history") == 8 */
+ strcpy (return_val, home);
+ return_val[home_len] = '/';
+#if defined (__MSDOS__)
+ strcpy (return_val + home_len + 1, "_history");
+#else
+ strcpy (return_val + home_len + 1, ".history");
+#endif
+
+ return (return_val);
+}
+
+static char *
+history_backupfile (const char *filename)
+{
+ const char *fn;
+ char *ret, linkbuf[PATH_MAX+1];
+ size_t len;
+ ssize_t n;
+ struct stat fs;
+
+ fn = filename;
+#if defined (HAVE_READLINK)
+ /* Follow symlink to avoid backing up symlink itself; call will fail if
+ not a symlink */
+ if ((n = readlink (filename, linkbuf, sizeof (linkbuf) - 1)) > 0)
+ {
+ linkbuf[n] = '\0';
+ fn = linkbuf;
+ }
+#endif
+
+ len = strlen (fn);
+ ret = xmalloc (len + 2);
+ strcpy (ret, fn);
+ ret[len] = '-';
+ ret[len+1] = '\0';
+ return ret;
+}
+
+static char *
+history_tempfile (const char *filename)
+{
+ const char *fn;
+ char *ret, linkbuf[PATH_MAX+1];
+ size_t len;
+ ssize_t n;
+ struct stat fs;
+ int pid;
+
+ fn = filename;
+#if defined (HAVE_READLINK)
+ /* Follow symlink so tempfile created in the same directory as any symlinked
+ history file; call will fail if not a symlink */
+ if ((n = readlink (filename, linkbuf, sizeof (linkbuf) - 1)) > 0)
+ {
+ linkbuf[n] = '\0';
+ fn = linkbuf;
+ }
+#endif
+
+ len = strlen (fn);
+ ret = xmalloc (len + 11);
+ strcpy (ret, fn);
+
+ pid = (int)getpid ();
+
+ /* filename-PID.tmp */
+ ret[len] = '-';
+ ret[len+1] = (pid / 10000 % 10) + '0';
+ ret[len+2] = (pid / 1000 % 10) + '0';
+ ret[len+3] = (pid / 100 % 10) + '0';
+ ret[len+4] = (pid / 10 % 10) + '0';
+ ret[len+5] = (pid % 10) + '0';
+ strcpy (ret + len + 6, ".tmp");
+
+ return ret;
+}
+
+/* Add the contents of FILENAME to the history list, a line at a time.
+ If FILENAME is NULL, then read from ~/.history. Returns 0 if
+ successful, or errno if not. */
+int
+read_history (const char *filename)
+{
+ return (read_history_range (filename, 0, -1));
+}
+
+/* Read a range of lines from FILENAME, adding them to the history list.
+ Start reading at the FROM'th line and end at the TO'th. If FROM
+ is zero, start at the beginning. If TO is less than FROM, read
+ until the end of the file. If FILENAME is NULL, then read from
+ ~/.history. Returns 0 if successful, or errno if not. */
+int
+read_history_range (const char *filename, int from, int to)
+{
+ register char *line_start, *line_end, *p;
+ char *input, *buffer, *bufend, *last_ts;
+ int file, current_line, chars_read, has_timestamps, reset_comment_char;
+ struct stat finfo;
+ size_t file_size;
+#if defined (EFBIG)
+ int overflow_errno = EFBIG;
+#elif defined (EOVERFLOW)
+ int overflow_errno = EOVERFLOW;
+#else
+ int overflow_errno = EIO;
+#endif
+
+ history_lines_read_from_file = 0;
+
+ buffer = last_ts = (char *)NULL;
+ input = history_filename (filename);
+ file = input ? open (input, O_RDONLY|O_BINARY, 0666) : -1;
+
+ if ((file < 0) || (fstat (file, &finfo) == -1))
+ goto error_and_exit;
+
+ if (S_ISREG (finfo.st_mode) == 0)
+ {
+#ifdef EFTYPE
+ errno = EFTYPE;
+#else
+ errno = EINVAL;
+#endif
+ goto error_and_exit;
+ }
+
+ file_size = (size_t)finfo.st_size;
+
+ /* check for overflow on very large files */
+ if (file_size != finfo.st_size || file_size + 1 < file_size)
+ {
+ errno = overflow_errno;
+ goto error_and_exit;
+ }
+
+ if (file_size == 0)
+ {
+ free (input);
+ return 0; /* don't waste time if we don't have to */
+ }
+
+#ifdef HISTORY_USE_MMAP
+ /* We map read/write and private so we can change newlines to NULs without
+ affecting the underlying object. */
+ buffer = (char *)mmap (0, file_size, PROT_READ|PROT_WRITE, MAP_RFLAGS, file, 0);
+ if ((void *)buffer == MAP_FAILED)
+ {
+ errno = overflow_errno;
+ goto error_and_exit;
+ }
+ chars_read = file_size;
+#else
+ buffer = (char *)malloc (file_size + 1);
+ if (buffer == 0)
+ {
+ errno = overflow_errno;
+ goto error_and_exit;
+ }
+
+ chars_read = read (file, buffer, file_size);
+#endif
+ if (chars_read < 0)
+ {
+ error_and_exit:
+ if (errno != 0)
+ chars_read = errno;
+ else
+ chars_read = EIO;
+ if (file >= 0)
+ close (file);
+
+ FREE (input);
+#ifndef HISTORY_USE_MMAP
+ FREE (buffer);
+#endif
+
+ return (chars_read);
+ }
+
+ close (file);
+
+ /* Set TO to larger than end of file if negative. */
+ if (to < 0)
+ to = chars_read;
+
+ /* Start at beginning of file, work to end. */
+ bufend = buffer + chars_read;
+ *bufend = '\0'; /* null-terminate buffer for timestamp checks */
+ current_line = 0;
+
+ /* Heuristic: the history comment character rarely changes, so assume we
+ have timestamps if the buffer starts with `#[:digit:]' and temporarily
+ set history_comment_char so timestamp parsing works right */
+ reset_comment_char = 0;
+ if (history_comment_char == '\0' && buffer[0] == '#' && isdigit ((unsigned char)buffer[1]))
+ {
+ history_comment_char = '#';
+ reset_comment_char = 1;
+ }
+
+ has_timestamps = HIST_TIMESTAMP_START (buffer);
+ history_multiline_entries += has_timestamps && history_write_timestamps;
+
+ /* Skip lines until we are at FROM. */
+ for (line_start = line_end = buffer; line_end < bufend && current_line < from; line_end++)
+ if (*line_end == '\n')
+ {
+ p = line_end + 1;
+ /* If we see something we think is a timestamp, continue with this
+ line. We should check more extensively here... */
+ if (HIST_TIMESTAMP_START(p) == 0)
+ current_line++;
+ line_start = p;
+ }
+
+ /* If there are lines left to gobble, then gobble them now. */
+ for (line_end = line_start; line_end < bufend; line_end++)
+ if (*line_end == '\n')
+ {
+ /* Change to allow Windows-like \r\n end of line delimiter. */
+ if (line_end > line_start && line_end[-1] == '\r')
+ line_end[-1] = '\0';
+ else
+ *line_end = '\0';
+
+ if (*line_start)
+ {
+ if (HIST_TIMESTAMP_START(line_start) == 0)
+ {
+ if (last_ts == NULL && history_length > 0 && history_multiline_entries)
+ _hs_append_history_line (history_length - 1, line_start);
+ else
+ add_history (line_start);
+ if (last_ts)
+ {
+ add_history_time (last_ts);
+ last_ts = NULL;
+ }
+ }
+ else
+ {
+ last_ts = line_start;
+ current_line--;
+ }
+ }
+
+ current_line++;
+
+ if (current_line >= to)
+ break;
+
+ line_start = line_end + 1;
+ }
+
+ history_lines_read_from_file = current_line;
+ if (reset_comment_char)
+ history_comment_char = '\0';
+
+ FREE (input);
+#ifndef HISTORY_USE_MMAP
+ FREE (buffer);
+#else
+ munmap (buffer, file_size);
+#endif
+
+ return (0);
+}
+
+/* Save FILENAME to BACK, handling case where FILENAME is a symlink
+ (e.g., ~/.bash_history -> .histfiles/.bash_history.$HOSTNAME) */
+static int
+histfile_backup (const char *filename, const char *back)
+{
+#if defined (HAVE_READLINK)
+ char linkbuf[PATH_MAX+1];
+ ssize_t n;
+
+ /* Follow to target of symlink to avoid renaming symlink itself */
+ if ((n = readlink (filename, linkbuf, sizeof (linkbuf) - 1)) > 0)
+ {
+ linkbuf[n] = '\0';
+ return (rename (linkbuf, back));
+ }
+#endif
+ return (rename (filename, back));
+}
+
+/* Restore ORIG from BACKUP handling case where ORIG is a symlink
+ (e.g., ~/.bash_history -> .histfiles/.bash_history.$HOSTNAME) */
+static int
+histfile_restore (const char *backup, const char *orig)
+{
+#if defined (HAVE_READLINK)
+ char linkbuf[PATH_MAX+1];
+ ssize_t n;
+
+ /* Follow to target of symlink to avoid renaming symlink itself */
+ if ((n = readlink (orig, linkbuf, sizeof (linkbuf) - 1)) > 0)
+ {
+ linkbuf[n] = '\0';
+ return (rename (backup, linkbuf));
+ }
+#endif
+ return (rename (backup, orig));
+}
+
+/* Truncate the history file FNAME, leaving only LINES trailing lines.
+ If FNAME is NULL, then use ~/.history. Writes a new file and renames
+ it to the original name. Returns 0 on success, errno on failure. */
+int
+history_truncate_file (const char *fname, int lines)
+{
+ char *buffer, *filename, *tempname, *bp, *bp1; /* bp1 == bp+1 */
+ int file, chars_read, rv, orig_lines, exists, r;
+ struct stat finfo;
+ size_t file_size;
+
+ history_lines_written_to_file = 0;
+
+ buffer = (char *)NULL;
+ filename = history_filename (fname);
+ tempname = 0;
+ file = filename ? open (filename, O_RDONLY|O_BINARY, 0666) : -1;
+ rv = exists = 0;
+
+ /* Don't try to truncate non-regular files. */
+ if (file == -1 || fstat (file, &finfo) == -1)
+ {
+ rv = errno;
+ if (file != -1)
+ close (file);
+ goto truncate_exit;
+ }
+ exists = 1;
+
+ if (S_ISREG (finfo.st_mode) == 0)
+ {
+ close (file);
+#ifdef EFTYPE
+ rv = EFTYPE;
+#else
+ rv = EINVAL;
+#endif
+ goto truncate_exit;
+ }
+
+ file_size = (size_t)finfo.st_size;
+
+ /* check for overflow on very large files */
+ if (file_size != finfo.st_size || file_size + 1 < file_size)
+ {
+ close (file);
+#if defined (EFBIG)
+ rv = errno = EFBIG;
+#elif defined (EOVERFLOW)
+ rv = errno = EOVERFLOW;
+#else
+ rv = errno = EINVAL;
+#endif
+ goto truncate_exit;
+ }
+
+ buffer = (char *)malloc (file_size + 1);
+ if (buffer == 0)
+ {
+ rv = errno;
+ close (file);
+ goto truncate_exit;
+ }
+
+ chars_read = read (file, buffer, file_size);
+ close (file);
+
+ if (chars_read <= 0)
+ {
+ rv = (chars_read < 0) ? errno : 0;
+ goto truncate_exit;
+ }
+
+ orig_lines = lines;
+ /* Count backwards from the end of buffer until we have passed
+ LINES lines. bp1 is set funny initially. But since bp[1] can't
+ be a comment character (since it's off the end) and *bp can't be
+ both a newline and the history comment character, it should be OK. */
+ for (bp1 = bp = buffer + chars_read - 1; lines && bp > buffer; bp--)
+ {
+ if (*bp == '\n' && HIST_TIMESTAMP_START(bp1) == 0)
+ lines--;
+ bp1 = bp;
+ }
+
+ /* If this is the first line, then the file contains exactly the
+ number of lines we want to truncate to, so we don't need to do
+ anything. It's the first line if we don't find a newline between
+ the current value of i and 0. Otherwise, write from the start of
+ this line until the end of the buffer. */
+ for ( ; bp > buffer; bp--)
+ {
+ if (*bp == '\n' && HIST_TIMESTAMP_START(bp1) == 0)
+ {
+ bp++;
+ break;
+ }
+ bp1 = bp;
+ }
+
+ /* Write only if there are more lines in the file than we want to
+ truncate to. */
+ if (bp <= buffer)
+ {
+ rv = 0;
+ /* No-op if LINES == 0 at this point */
+ history_lines_written_to_file = orig_lines - lines;
+ goto truncate_exit;
+ }
+
+ tempname = history_tempfile (filename);
+
+ if ((file = open (tempname, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0600)) != -1)
+ {
+ if (write (file, bp, chars_read - (bp - buffer)) < 0)
+ rv = errno;
+
+ if (close (file) < 0 && rv == 0)
+ rv = errno;
+ }
+ else
+ rv = errno;
+
+ truncate_exit:
+ FREE (buffer);
+
+ history_lines_written_to_file = orig_lines - lines;
+
+ if (rv == 0 && filename && tempname)
+ rv = histfile_restore (tempname, filename);
+
+ if (rv != 0)
+ {
+ if (tempname)
+ unlink (tempname);
+ history_lines_written_to_file = 0;
+ }
+
+#if defined (HAVE_CHOWN)
+ /* Make sure the new filename is owned by the same user as the old. If one
+ user is running this, it's a no-op. If the shell is running after sudo
+ with a shared history file, we don't want to leave the history file
+ owned by root. */
+ if (rv == 0 && exists)
+ r = chown (filename, finfo.st_uid, finfo.st_gid);
+#endif
+
+ xfree (filename);
+ FREE (tempname);
+
+ return rv;
+}
+
+/* Workhorse function for writing history. Writes the last NELEMENT entries
+ from the history list to FILENAME. OVERWRITE is non-zero if you
+ wish to replace FILENAME with the entries. */
+static int
+history_do_write (const char *filename, int nelements, int overwrite)
+{
+ register int i;
+ char *output, *tempname, *histname;
+ int file, mode, rv, exists;
+ struct stat finfo;
+#ifdef HISTORY_USE_MMAP
+ size_t cursize;
+
+ history_lines_written_to_file = 0;
+
+ mode = overwrite ? O_RDWR|O_CREAT|O_TRUNC|O_BINARY : O_RDWR|O_APPEND|O_BINARY;
+#else
+ mode = overwrite ? O_WRONLY|O_CREAT|O_TRUNC|O_BINARY : O_WRONLY|O_APPEND|O_BINARY;
+#endif
+ histname = history_filename (filename);
+ exists = histname ? (stat (histname, &finfo) == 0) : 0;
+
+ tempname = (overwrite && exists && S_ISREG (finfo.st_mode)) ? history_tempfile (histname) : 0;
+ output = tempname ? tempname : histname;
+
+ file = output ? open (output, mode, 0600) : -1;
+ rv = 0;
+
+ if (file == -1)
+ {
+ rv = errno;
+ FREE (histname);
+ FREE (tempname);
+ return (rv);
+ }
+
+#ifdef HISTORY_USE_MMAP
+ cursize = overwrite ? 0 : lseek (file, 0, SEEK_END);
+#endif
+
+ if (nelements > history_length)
+ nelements = history_length;
+
+ /* Build a buffer of all the lines to write, and write them in one syscall.
+ Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */
+ {
+ HIST_ENTRY **the_history; /* local */
+ register int j;
+ int buffer_size;
+ char *buffer;
+
+ the_history = history_list ();
+ /* Calculate the total number of bytes to write. */
+ for (buffer_size = 0, i = history_length - nelements; i < history_length; i++)
+#if 0
+ buffer_size += 2 + HISTENT_BYTES (the_history[i]);
+#else
+ {
+ if (history_write_timestamps && the_history[i]->timestamp && the_history[i]->timestamp[0])
+ buffer_size += strlen (the_history[i]->timestamp) + 1;
+ buffer_size += strlen (the_history[i]->line) + 1;
+ }
+#endif
+
+ /* Allocate the buffer, and fill it. */
+#ifdef HISTORY_USE_MMAP
+ if (ftruncate (file, buffer_size+cursize) == -1)
+ goto mmap_error;
+ buffer = (char *)mmap (0, buffer_size, PROT_READ|PROT_WRITE, MAP_WFLAGS, file, cursize);
+ if ((void *)buffer == MAP_FAILED)
+ {
+mmap_error:
+ rv = errno;
+ close (file);
+ if (tempname)
+ unlink (tempname);
+ FREE (histname);
+ FREE (tempname);
+ return rv;
+ }
+#else
+ buffer = (char *)malloc (buffer_size);
+ if (buffer == 0)
+ {
+ rv = errno;
+ close (file);
+ if (tempname)
+ unlink (tempname);
+ FREE (histname);
+ FREE (tempname);
+ return rv;
+ }
+#endif
+
+ for (j = 0, i = history_length - nelements; i < history_length; i++)
+ {
+ if (history_write_timestamps && the_history[i]->timestamp && the_history[i]->timestamp[0])
+ {
+ strcpy (buffer + j, the_history[i]->timestamp);
+ j += strlen (the_history[i]->timestamp);
+ buffer[j++] = '\n';
+ }
+ strcpy (buffer + j, the_history[i]->line);
+ j += strlen (the_history[i]->line);
+ buffer[j++] = '\n';
+ }
+
+#ifdef HISTORY_USE_MMAP
+ if (msync (buffer, buffer_size, MS_ASYNC) != 0 || munmap (buffer, buffer_size) != 0)
+ rv = errno;
+#else
+ if (write (file, buffer, buffer_size) < 0)
+ rv = errno;
+ xfree (buffer);
+#endif
+ }
+
+ history_lines_written_to_file = nelements;
+
+ if (close (file) < 0 && rv == 0)
+ rv = errno;
+
+ if (rv == 0 && histname && tempname)
+ rv = histfile_restore (tempname, histname);
+
+ if (rv != 0)
+ {
+ if (tempname)
+ unlink (tempname);
+ history_lines_written_to_file = 0;
+ }
+
+#if defined (HAVE_CHOWN)
+ /* Make sure the new filename is owned by the same user as the old. If one
+ user is running this, it's a no-op. If the shell is running after sudo
+ with a shared history file, we don't want to leave the history file
+ owned by root. */
+ if (rv == 0 && exists)
+ mode = chown (histname, finfo.st_uid, finfo.st_gid);
+#endif
+
+ FREE (histname);
+ FREE (tempname);
+
+ return (rv);
+}
+
+/* Append NELEMENT entries to FILENAME. The entries appended are from
+ the end of the list minus NELEMENTs up to the end of the list. */
+int
+append_history (int nelements, const char *filename)
+{
+ return (history_do_write (filename, nelements, HISTORY_APPEND));
+}
+
+/* Overwrite FILENAME with the current history. If FILENAME is NULL,
+ then write the history list to ~/.history. Values returned
+ are as in read_history ().*/
+int
+write_history (const char *filename)
+{
+ return (history_do_write (filename, history_length, HISTORY_OVERWRITE));
+}