Annotation of embedaddon/readline/histfile.c, revision 1.1.1.1

1.1       misho       1: /* histfile.c - functions to manipulate the history file. */
                      2: 
                      3: /* Copyright (C) 1989-2010 Free Software Foundation, Inc.
                      4: 
                      5:    This file contains the GNU History Library (History), a set of
                      6:    routines for managing the text of previously typed lines.
                      7: 
                      8:    History 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 3 of the License, or
                     11:    (at your option) any later version.
                     12: 
                     13:    History is distributed in the hope that it will be useful,
                     14:    but WITHOUT ANY WARRANTY; without even the implied warranty of
                     15:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     16:    GNU General Public License for more details.
                     17: 
                     18:    You should have received a copy of the GNU General Public License
                     19:    along with History.  If not, see <http://www.gnu.org/licenses/>.
                     20: */
                     21: 
                     22: /* The goal is to make the implementation transparent, so that you
                     23:    don't have to know what data types are used, just what functions
                     24:    you can call.  I think I have done that. */
                     25: 
                     26: #define READLINE_LIBRARY
                     27: 
                     28: #if defined (__TANDEM)
                     29: #  include <floss.h>
                     30: #endif
                     31: 
                     32: #if defined (HAVE_CONFIG_H)
                     33: #  include <config.h>
                     34: #endif
                     35: 
                     36: #include <stdio.h>
                     37: 
                     38: #include <sys/types.h>
                     39: #if ! defined (_MINIX) && defined (HAVE_SYS_FILE_H)
                     40: #  include <sys/file.h>
                     41: #endif
                     42: #include "posixstat.h"
                     43: #include <fcntl.h>
                     44: 
                     45: #if defined (HAVE_STDLIB_H)
                     46: #  include <stdlib.h>
                     47: #else
                     48: #  include "ansi_stdlib.h"
                     49: #endif /* HAVE_STDLIB_H */
                     50: 
                     51: #if defined (HAVE_UNISTD_H)
                     52: #  include <unistd.h>
                     53: #endif
                     54: 
                     55: #include <ctype.h>
                     56: 
                     57: #if defined (__EMX__)
                     58: #  undef HAVE_MMAP
                     59: #endif
                     60: 
                     61: #ifdef HISTORY_USE_MMAP
                     62: #  include <sys/mman.h>
                     63: 
                     64: #  ifdef MAP_FILE
                     65: #    define MAP_RFLAGS (MAP_FILE|MAP_PRIVATE)
                     66: #    define MAP_WFLAGS (MAP_FILE|MAP_SHARED)
                     67: #  else
                     68: #    define MAP_RFLAGS MAP_PRIVATE
                     69: #    define MAP_WFLAGS MAP_SHARED
                     70: #  endif
                     71: 
                     72: #  ifndef MAP_FAILED
                     73: #    define MAP_FAILED ((void *)-1)
                     74: #  endif
                     75: 
                     76: #endif /* HISTORY_USE_MMAP */
                     77: 
                     78: /* If we're compiling for __EMX__ (OS/2) or __CYGWIN__ (cygwin32 environment
                     79:    on win 95/98/nt), we want to open files with O_BINARY mode so that there
                     80:    is no \n -> \r\n conversion performed.  On other systems, we don't want to
                     81:    mess around with O_BINARY at all, so we ensure that it's defined to 0. */
                     82: #if defined (__EMX__) || defined (__CYGWIN__)
                     83: #  ifndef O_BINARY
                     84: #    define O_BINARY 0
                     85: #  endif
                     86: #else /* !__EMX__ && !__CYGWIN__ */
                     87: #  undef O_BINARY
                     88: #  define O_BINARY 0
                     89: #endif /* !__EMX__ && !__CYGWIN__ */
                     90: 
                     91: #include <errno.h>
                     92: #if !defined (errno)
                     93: extern int errno;
                     94: #endif /* !errno */
                     95: 
                     96: #include "history.h"
                     97: #include "histlib.h"
                     98: 
                     99: #include "rlshell.h"
                    100: #include "xmalloc.h"
                    101: 
                    102: /* If non-zero, we write timestamps to the history file in history_do_write() */
                    103: int history_write_timestamps = 0;
                    104: 
                    105: /* Does S look like the beginning of a history timestamp entry?  Placeholder
                    106:    for more extensive tests. */
                    107: #define HIST_TIMESTAMP_START(s)                (*(s) == history_comment_char && isdigit ((s)[1]) )
                    108: 
                    109: /* Return the string that should be used in the place of this
                    110:    filename.  This only matters when you don't specify the
                    111:    filename to read_history (), or write_history (). */
                    112: static char *
                    113: history_filename (filename)
                    114:      const char *filename;
                    115: {
                    116:   char *return_val;
                    117:   const char *home;
                    118:   int home_len;
                    119: 
                    120:   return_val = filename ? savestring (filename) : (char *)NULL;
                    121: 
                    122:   if (return_val)
                    123:     return (return_val);
                    124:   
                    125:   home = sh_get_env_value ("HOME");
                    126: 
                    127:   if (home == 0)
                    128:     return (NULL);
                    129:   else
                    130:     home_len = strlen (home);
                    131: 
                    132:   return_val = (char *)xmalloc (2 + home_len + 8); /* strlen(".history") == 8 */
                    133:   strcpy (return_val, home);
                    134:   return_val[home_len] = '/';
                    135: #if defined (__MSDOS__)
                    136:   strcpy (return_val + home_len + 1, "_history");
                    137: #else
                    138:   strcpy (return_val + home_len + 1, ".history");
                    139: #endif
                    140: 
                    141:   return (return_val);
                    142: }
                    143: 
                    144: static char *
                    145: history_backupfile (filename)
                    146:      const char *filename;
                    147: {
                    148:   char *ret;
                    149:   size_t len;
                    150: 
                    151:   len = strlen (filename);
                    152:   ret = xmalloc (len + 2);
                    153:   strcpy (ret, filename);
                    154:   ret[len] = '-';
                    155:   ret[len+1] = '\0';
                    156:   return ret;
                    157: }
                    158:   
                    159: /* Add the contents of FILENAME to the history list, a line at a time.
                    160:    If FILENAME is NULL, then read from ~/.history.  Returns 0 if
                    161:    successful, or errno if not. */
                    162: int
                    163: read_history (filename)
                    164:      const char *filename;
                    165: {
                    166:   return (read_history_range (filename, 0, -1));
                    167: }
                    168: 
                    169: /* Read a range of lines from FILENAME, adding them to the history list.
                    170:    Start reading at the FROM'th line and end at the TO'th.  If FROM
                    171:    is zero, start at the beginning.  If TO is less than FROM, read
                    172:    until the end of the file.  If FILENAME is NULL, then read from
                    173:    ~/.history.  Returns 0 if successful, or errno if not. */
                    174: int
                    175: read_history_range (filename, from, to)
                    176:      const char *filename;
                    177:      int from, to;
                    178: {
                    179:   register char *line_start, *line_end, *p;
                    180:   char *input, *buffer, *bufend, *last_ts;
                    181:   int file, current_line, chars_read;
                    182:   struct stat finfo;
                    183:   size_t file_size;
                    184: #if defined (EFBIG)
                    185:   int overflow_errno = EFBIG;
                    186: #elif defined (EOVERFLOW)
                    187:   int overflow_errno = EOVERFLOW;
                    188: #else
                    189:   int overflow_errno = EIO;
                    190: #endif
                    191: 
                    192:   buffer = last_ts = (char *)NULL;
                    193:   input = history_filename (filename);
                    194:   file = input ? open (input, O_RDONLY|O_BINARY, 0666) : -1;
                    195: 
                    196:   if ((file < 0) || (fstat (file, &finfo) == -1))
                    197:     goto error_and_exit;
                    198: 
                    199:   file_size = (size_t)finfo.st_size;
                    200: 
                    201:   /* check for overflow on very large files */
                    202:   if (file_size != finfo.st_size || file_size + 1 < file_size)
                    203:     {
                    204:       errno = overflow_errno;
                    205:       goto error_and_exit;
                    206:     }
                    207: 
                    208: #ifdef HISTORY_USE_MMAP
                    209:   /* We map read/write and private so we can change newlines to NULs without
                    210:      affecting the underlying object. */
                    211:   buffer = (char *)mmap (0, file_size, PROT_READ|PROT_WRITE, MAP_RFLAGS, file, 0);
                    212:   if ((void *)buffer == MAP_FAILED)
                    213:     {
                    214:       errno = overflow_errno;
                    215:       goto error_and_exit;
                    216:     }
                    217:   chars_read = file_size;
                    218: #else
                    219:   buffer = (char *)malloc (file_size + 1);
                    220:   if (buffer == 0)
                    221:     {
                    222:       errno = overflow_errno;
                    223:       goto error_and_exit;
                    224:     }
                    225: 
                    226:   chars_read = read (file, buffer, file_size);
                    227: #endif
                    228:   if (chars_read < 0)
                    229:     {
                    230:   error_and_exit:
                    231:       if (errno != 0)
                    232:        chars_read = errno;
                    233:       else
                    234:        chars_read = EIO;
                    235:       if (file >= 0)
                    236:        close (file);
                    237: 
                    238:       FREE (input);
                    239: #ifndef HISTORY_USE_MMAP
                    240:       FREE (buffer);
                    241: #endif
                    242: 
                    243:       return (chars_read);
                    244:     }
                    245: 
                    246:   close (file);
                    247: 
                    248:   /* Set TO to larger than end of file if negative. */
                    249:   if (to < 0)
                    250:     to = chars_read;
                    251: 
                    252:   /* Start at beginning of file, work to end. */
                    253:   bufend = buffer + chars_read;
                    254:   current_line = 0;
                    255: 
                    256:   /* Skip lines until we are at FROM. */
                    257:   for (line_start = line_end = buffer; line_end < bufend && current_line < from; line_end++)
                    258:     if (*line_end == '\n')
                    259:       {
                    260:        p = line_end + 1;
                    261:        /* If we see something we think is a timestamp, continue with this
                    262:           line.  We should check more extensively here... */
                    263:        if (HIST_TIMESTAMP_START(p) == 0)
                    264:          current_line++;
                    265:        line_start = p;
                    266:       }
                    267: 
                    268:   /* If there are lines left to gobble, then gobble them now. */
                    269:   for (line_end = line_start; line_end < bufend; line_end++)
                    270:     if (*line_end == '\n')
                    271:       {
                    272:        /* Change to allow Windows-like \r\n end of line delimiter. */
                    273:        if (line_end > line_start && line_end[-1] == '\r')
                    274:          line_end[-1] = '\0';
                    275:        else
                    276:          *line_end = '\0';
                    277: 
                    278:        if (*line_start)
                    279:          {
                    280:            if (HIST_TIMESTAMP_START(line_start) == 0)
                    281:              {
                    282:                add_history (line_start);
                    283:                if (last_ts)
                    284:                  {
                    285:                    add_history_time (last_ts);
                    286:                    last_ts = NULL;
                    287:                  }
                    288:              }
                    289:            else
                    290:              {
                    291:                last_ts = line_start;
                    292:                current_line--;
                    293:              }
                    294:          }
                    295: 
                    296:        current_line++;
                    297: 
                    298:        if (current_line >= to)
                    299:          break;
                    300: 
                    301:        line_start = line_end + 1;
                    302:       }
                    303: 
                    304:   FREE (input);
                    305: #ifndef HISTORY_USE_MMAP
                    306:   FREE (buffer);
                    307: #else
                    308:   munmap (buffer, file_size);
                    309: #endif
                    310: 
                    311:   return (0);
                    312: }
                    313: 
                    314: /* Truncate the history file FNAME, leaving only LINES trailing lines.
                    315:    If FNAME is NULL, then use ~/.history.  Returns 0 on success, errno
                    316:    on failure. */
                    317: int
                    318: history_truncate_file (fname, lines)
                    319:      const char *fname;
                    320:      int lines;
                    321: {
                    322:   char *buffer, *filename, *bp, *bp1;          /* bp1 == bp+1 */
                    323:   int file, chars_read, rv;
                    324:   struct stat finfo;
                    325:   size_t file_size;
                    326: 
                    327:   buffer = (char *)NULL;
                    328:   filename = history_filename (fname);
                    329:   file = filename ? open (filename, O_RDONLY|O_BINARY, 0666) : -1;
                    330:   rv = 0;
                    331: 
                    332:   /* Don't try to truncate non-regular files. */
                    333:   if (file == -1 || fstat (file, &finfo) == -1)
                    334:     {
                    335:       rv = errno;
                    336:       if (file != -1)
                    337:        close (file);
                    338:       goto truncate_exit;
                    339:     }
                    340: 
                    341:   if (S_ISREG (finfo.st_mode) == 0)
                    342:     {
                    343:       close (file);
                    344: #ifdef EFTYPE
                    345:       rv = EFTYPE;
                    346: #else
                    347:       rv = EINVAL;
                    348: #endif
                    349:       goto truncate_exit;
                    350:     }
                    351: 
                    352:   file_size = (size_t)finfo.st_size;
                    353: 
                    354:   /* check for overflow on very large files */
                    355:   if (file_size != finfo.st_size || file_size + 1 < file_size)
                    356:     {
                    357:       close (file);
                    358: #if defined (EFBIG)
                    359:       rv = errno = EFBIG;
                    360: #elif defined (EOVERFLOW)
                    361:       rv = errno = EOVERFLOW;
                    362: #else
                    363:       rv = errno = EINVAL;
                    364: #endif
                    365:       goto truncate_exit;
                    366:     }
                    367: 
                    368:   buffer = (char *)malloc (file_size + 1);
                    369:   if (buffer == 0)
                    370:     {
                    371:       close (file);
                    372:       goto truncate_exit;
                    373:     }
                    374: 
                    375:   chars_read = read (file, buffer, file_size);
                    376:   close (file);
                    377: 
                    378:   if (chars_read <= 0)
                    379:     {
                    380:       rv = (chars_read < 0) ? errno : 0;
                    381:       goto truncate_exit;
                    382:     }
                    383: 
                    384:   /* Count backwards from the end of buffer until we have passed
                    385:      LINES lines.  bp1 is set funny initially.  But since bp[1] can't
                    386:      be a comment character (since it's off the end) and *bp can't be
                    387:      both a newline and the history comment character, it should be OK. */
                    388:   for (bp1 = bp = buffer + chars_read - 1; lines && bp > buffer; bp--)
                    389:     {
                    390:       if (*bp == '\n' && HIST_TIMESTAMP_START(bp1) == 0)
                    391:        lines--;
                    392:       bp1 = bp;
                    393:     }
                    394: 
                    395:   /* If this is the first line, then the file contains exactly the
                    396:      number of lines we want to truncate to, so we don't need to do
                    397:      anything.  It's the first line if we don't find a newline between
                    398:      the current value of i and 0.  Otherwise, write from the start of
                    399:      this line until the end of the buffer. */
                    400:   for ( ; bp > buffer; bp--)
                    401:     {
                    402:       if (*bp == '\n' && HIST_TIMESTAMP_START(bp1) == 0)
                    403:         {
                    404:          bp++;
                    405:          break;
                    406:         }
                    407:       bp1 = bp;
                    408:     }
                    409: 
                    410:   /* Write only if there are more lines in the file than we want to
                    411:      truncate to. */
                    412:   if (bp > buffer && ((file = open (filename, O_WRONLY|O_TRUNC|O_BINARY, 0600)) != -1))
                    413:     {
                    414:       if (write (file, bp, chars_read - (bp - buffer)) < 0)
                    415:        rv = errno;
                    416: 
                    417: #if defined (__BEOS__)
                    418:       /* BeOS ignores O_TRUNC. */
                    419:       ftruncate (file, chars_read - (bp - buffer));
                    420: #endif
                    421: 
                    422:       if (close (file) < 0 && rv == 0)
                    423:        rv = errno;
                    424:     }
                    425: 
                    426:  truncate_exit:
                    427: 
                    428:   FREE (buffer);
                    429: 
                    430:   xfree (filename);
                    431:   return rv;
                    432: }
                    433: 
                    434: /* Workhorse function for writing history.  Writes NELEMENT entries
                    435:    from the history list to FILENAME.  OVERWRITE is non-zero if you
                    436:    wish to replace FILENAME with the entries. */
                    437: static int
                    438: history_do_write (filename, nelements, overwrite)
                    439:      const char *filename;
                    440:      int nelements, overwrite;
                    441: {
                    442:   register int i;
                    443:   char *output, *bakname;
                    444:   int file, mode, rv;
                    445: #ifdef HISTORY_USE_MMAP
                    446:   size_t cursize;
                    447: 
                    448:   mode = overwrite ? O_RDWR|O_CREAT|O_TRUNC|O_BINARY : O_RDWR|O_APPEND|O_BINARY;
                    449: #else
                    450:   mode = overwrite ? O_WRONLY|O_CREAT|O_TRUNC|O_BINARY : O_WRONLY|O_APPEND|O_BINARY;
                    451: #endif
                    452:   output = history_filename (filename);
                    453:   bakname = (overwrite && output) ? history_backupfile (output) : 0;
                    454: 
                    455:   if (output && bakname)
                    456:     rename (output, bakname);
                    457: 
                    458:   file = output ? open (output, mode, 0600) : -1;
                    459:   rv = 0;
                    460: 
                    461:   if (file == -1)
                    462:     {
                    463:       rv = errno;
                    464:       if (output && bakname)
                    465:         rename (bakname, output);
                    466:       FREE (output);
                    467:       FREE (bakname);
                    468:       return (rv);
                    469:     }
                    470: 
                    471: #ifdef HISTORY_USE_MMAP
                    472:   cursize = overwrite ? 0 : lseek (file, 0, SEEK_END);
                    473: #endif
                    474: 
                    475:   if (nelements > history_length)
                    476:     nelements = history_length;
                    477: 
                    478:   /* Build a buffer of all the lines to write, and write them in one syscall.
                    479:      Suggested by Peter Ho (peter@robosts.oxford.ac.uk). */
                    480:   {
                    481:     HIST_ENTRY **the_history;  /* local */
                    482:     register int j;
                    483:     int buffer_size;
                    484:     char *buffer;
                    485: 
                    486:     the_history = history_list ();
                    487:     /* Calculate the total number of bytes to write. */
                    488:     for (buffer_size = 0, i = history_length - nelements; i < history_length; i++)
                    489: #if 0
                    490:       buffer_size += 2 + HISTENT_BYTES (the_history[i]);
                    491: #else
                    492:       {
                    493:        if (history_write_timestamps && the_history[i]->timestamp && the_history[i]->timestamp[0])
                    494:          buffer_size += strlen (the_history[i]->timestamp) + 1;
                    495:        buffer_size += strlen (the_history[i]->line) + 1;
                    496:       }
                    497: #endif
                    498: 
                    499:     /* Allocate the buffer, and fill it. */
                    500: #ifdef HISTORY_USE_MMAP
                    501:     if (ftruncate (file, buffer_size+cursize) == -1)
                    502:       goto mmap_error;
                    503:     buffer = (char *)mmap (0, buffer_size, PROT_READ|PROT_WRITE, MAP_WFLAGS, file, cursize);
                    504:     if ((void *)buffer == MAP_FAILED)
                    505:       {
                    506: mmap_error:
                    507:        rv = errno;
                    508:        close (file);
                    509:        if (output && bakname)
                    510:          rename (bakname, output);
                    511:        FREE (output);
                    512:        FREE (bakname);
                    513:        return rv;
                    514:       }
                    515: #else    
                    516:     buffer = (char *)malloc (buffer_size);
                    517:     if (buffer == 0)
                    518:       {
                    519:        rv = errno;
                    520:        close (file);
                    521:        if (output && bakname)
                    522:          rename (bakname, output);
                    523:        FREE (output);
                    524:        FREE (bakname);
                    525:        return rv;
                    526:       }
                    527: #endif
                    528: 
                    529:     for (j = 0, i = history_length - nelements; i < history_length; i++)
                    530:       {
                    531:        if (history_write_timestamps && the_history[i]->timestamp && the_history[i]->timestamp[0])
                    532:          {
                    533:            strcpy (buffer + j, the_history[i]->timestamp);
                    534:            j += strlen (the_history[i]->timestamp);
                    535:            buffer[j++] = '\n';
                    536:          }
                    537:        strcpy (buffer + j, the_history[i]->line);
                    538:        j += strlen (the_history[i]->line);
                    539:        buffer[j++] = '\n';
                    540:       }
                    541: 
                    542: #ifdef HISTORY_USE_MMAP
                    543:     if (msync (buffer, buffer_size, 0) != 0 || munmap (buffer, buffer_size) != 0)
                    544:       rv = errno;
                    545: #else
                    546:     if (write (file, buffer, buffer_size) < 0)
                    547:       rv = errno;
                    548:     xfree (buffer);
                    549: #endif
                    550:   }
                    551: 
                    552:   if (close (file) < 0 && rv == 0)
                    553:     rv = errno;
                    554: 
                    555:   if (rv != 0 && output && bakname)
                    556:     rename (bakname, output);
                    557:   else if (rv == 0 && bakname)
                    558:     unlink (bakname);
                    559: 
                    560:   FREE (output);
                    561:   FREE (bakname);
                    562: 
                    563:   return (rv);
                    564: }
                    565: 
                    566: /* Append NELEMENT entries to FILENAME.  The entries appended are from
                    567:    the end of the list minus NELEMENTs up to the end of the list. */
                    568: int
                    569: append_history (nelements, filename)
                    570:      int nelements;
                    571:      const char *filename;
                    572: {
                    573:   return (history_do_write (filename, nelements, HISTORY_APPEND));
                    574: }
                    575: 
                    576: /* Overwrite FILENAME with the current history.  If FILENAME is NULL,
                    577:    then write the history list to ~/.history.  Values returned
                    578:    are as in read_history ().*/
                    579: int
                    580: write_history (filename)
                    581:      const char *filename;
                    582: {
                    583:   return (history_do_write (filename, history_length, HISTORY_OVERWRITE));
                    584: }

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