1 /* histfile.c - functions to manipulate the history file. */
3 /* Copyright (C) 1989, 1992 Free Software Foundation, Inc.
5 This file contains the GNU History Library (the Library), a set of
6 routines for managing the text of previously typed lines.
8 The Library is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 The Library is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 The GNU General Public License is often shipped with GNU software, and
19 is generally kept in a file called COPYING or LICENSE. If you do not
20 have a copy of the license, write to the Free Software Foundation,
21 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
23 /* The goal is to make the implementation transparent, so that you
24 don't have to know what data types are used, just what functions
25 you can call. I think I have done that. */
26 #define READLINE_LIBRARY
28 #if defined (HAVE_CONFIG_H)
34 #include <sys/types.h>
36 # include <sys/file.h>
38 #include "posixstat.h"
41 #if defined (HAVE_STDLIB_H)
44 # include "ansi_stdlib.h"
45 #endif /* HAVE_STDLIB_H */
47 #if defined (HAVE_UNISTD_H)
51 #if defined (HAVE_STRING_H)
55 #endif /* !HAVE_STRING_H */
58 /* If we're compiling for __EMX__ (OS/2) or __CYGWIN__ (cygwin32 environment
59 on win 95/98/nt), we want to open files with O_BINARY mode so that there
60 is no \n -> \r\n conversion performed. On other systems, we don't want to
61 mess around with O_BINARY at all, so we ensure that it's defined to 0. */
62 #if defined (__EMX__) || defined (__CYGWIN__)
66 #else /* !__EMX__ && !__CYGWIN__ */
69 #endif /* !__EMX__ && !__CYGWIN__ */
82 /* Return the string that should be used in the place of this
83 filename. This only matters when you don't specify the
84 filename to read_history (), or write_history (). */
86 history_filename (filename
)
89 char *return_val
, *home
;
92 return_val
= filename
? savestring (filename
) : (char *)NULL
;
97 home
= get_env_value ("HOME");
105 home_len
= strlen (home
);
107 return_val
= xmalloc (2 + home_len
+ 8); /* strlen(".history") == 8 */
108 strcpy (return_val
, home
);
109 return_val
[home_len
] = '/';
110 #if defined (__MSDOS__)
111 strcpy (return_val
+ home_len
+ 1, "_history");
113 strcpy (return_val
+ home_len
+ 1, ".history");
119 /* Add the contents of FILENAME to the history list, a line at a time.
120 If FILENAME is NULL, then read from ~/.history. Returns 0 if
121 successful, or errno if not. */
123 read_history (filename
)
126 return (read_history_range (filename
, 0, -1));
129 /* Read a range of lines from FILENAME, adding them to the history list.
130 Start reading at the FROM'th line and end at the TO'th. If FROM
131 is zero, start at the beginning. If TO is less than FROM, read
132 until the end of the file. If FILENAME is NULL, then read from
133 ~/.history. Returns 0 if successful, or errno if not. */
135 read_history_range (filename
, from
, to
)
139 register int line_start
, line_end
;
140 char *input
, *buffer
;
141 int file
, current_line
, chars_read
;
145 buffer
= (char *)NULL
;
146 input
= history_filename (filename
);
147 file
= open (input
, O_RDONLY
|O_BINARY
, 0666);
149 if ((file
< 0) || (fstat (file
, &finfo
) == -1))
152 file_size
= (size_t)finfo
.st_size
;
154 /* check for overflow on very large files */
155 if (file_size
!= finfo
.st_size
|| file_size
+ 1 < file_size
)
163 buffer
= xmalloc (file_size
+ 1);
165 chars_read
= read (file
, buffer
, file_size
);
180 /* Set TO to larger than end of file if negative. */
184 /* Start at beginning of file, work to end. */
185 line_start
= line_end
= current_line
= 0;
187 /* Skip lines until we are at FROM. */
188 while (line_start
< chars_read
&& current_line
< from
)
190 for (line_end
= line_start
; line_end
< chars_read
; line_end
++)
191 if (buffer
[line_end
] == '\n')
194 line_start
= line_end
+ 1;
195 if (current_line
== from
)
200 /* If there are lines left to gobble, then gobble them now. */
201 for (line_end
= line_start
; line_end
< chars_read
; line_end
++)
202 if (buffer
[line_end
] == '\n')
204 buffer
[line_end
] = '\0';
206 if (buffer
[line_start
])
207 add_history (buffer
+ line_start
);
211 if (current_line
>= to
)
214 line_start
= line_end
+ 1;
223 /* Truncate the history file FNAME, leaving only LINES trailing lines.
224 If FNAME is NULL, then use ~/.history. */
226 history_truncate_file (fname
, lines
)
231 int file
, chars_read
;
232 char *buffer
, *filename
;
236 buffer
= (char *)NULL
;
237 filename
= history_filename (fname
);
238 file
= open (filename
, O_RDONLY
|O_BINARY
, 0666);
240 if (file
== -1 || fstat (file
, &finfo
) == -1)
243 /* Don't try to truncate non-regular files. */
244 if (S_ISREG(finfo
.st_mode
) == 0)
247 file_size
= (size_t)finfo
.st_size
;
249 /* check for overflow on very large files */
250 if (file_size
!= finfo
.st_size
|| file_size
+ 1 < file_size
)
259 buffer
= xmalloc (file_size
+ 1);
260 chars_read
= read (file
, buffer
, file_size
);
266 /* Count backwards from the end of buffer until we have passed
268 for (i
= chars_read
- 1; lines
&& i
; i
--)
270 if (buffer
[i
] == '\n')
274 /* If this is the first line, then the file contains exactly the
275 number of lines we want to truncate to, so we don't need to do
276 anything. It's the first line if we don't find a newline between
277 the current value of i and 0. Otherwise, write from the start of
278 this line until the end of the buffer. */
280 if (buffer
[i
] == '\n')
286 /* Write only if there are more lines in the file than we want to
288 if (i
&& ((file
= open (filename
, O_WRONLY
|O_TRUNC
|O_BINARY
, 0600)) != -1))
290 write (file
, buffer
+ i
, chars_read
- i
);
292 #if defined (__BEOS__)
293 /* BeOS ignores O_TRUNC. */
294 ftruncate (file
, chars_read
- i
);
308 /* Workhorse function for writing history. Writes NELEMENT entries
309 from the history list to FILENAME. OVERWRITE is non-zero if you
310 wish to replace FILENAME with the entries. */
312 history_do_write (filename
, nelements
, overwrite
)
314 int nelements
, overwrite
;
320 mode
= overwrite
? O_WRONLY
|O_CREAT
|O_TRUNC
|O_BINARY
: O_WRONLY
|O_APPEND
|O_BINARY
;
321 output
= history_filename (filename
);
323 if ((file
= open (output
, mode
, 0600)) == -1)
329 if (nelements
> history_length
)
330 nelements
= history_length
;
332 /* Build a buffer of all the lines to write, and write them in one syscall.
333 Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */
335 HIST_ENTRY
**the_history
; /* local */
340 the_history
= history_list ();
341 /* Calculate the total number of bytes to write. */
342 for (buffer_size
= 0, i
= history_length
- nelements
; i
< history_length
; i
++)
343 buffer_size
+= 1 + strlen (the_history
[i
]->line
);
345 /* Allocate the buffer, and fill it. */
346 buffer
= xmalloc (buffer_size
);
348 for (j
= 0, i
= history_length
- nelements
; i
< history_length
; i
++)
350 strcpy (buffer
+ j
, the_history
[i
]->line
);
351 j
+= strlen (the_history
[i
]->line
);
355 write (file
, buffer
, buffer_size
);
366 /* Append NELEMENT entries to FILENAME. The entries appended are from
367 the end of the list minus NELEMENTs up to the end of the list. */
369 append_history (nelements
, filename
)
373 return (history_do_write (filename
, nelements
, HISTORY_APPEND
));
376 /* Overwrite FILENAME with the current history. If FILENAME is NULL,
377 then write the history list to ~/.history. Values returned
378 are as in read_history ().*/
380 write_history (filename
)
383 return (history_do_write (filename
, history_length
, HISTORY_OVERWRITE
));
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