文章详情

  • 游戏榜单
  • 软件榜单
关闭导航
热搜榜
热门下载
热门标签
php爱好者> php文档>split.c

split.c

时间:2006-07-31  来源:anima

/* split.c -- split a file into pieces.
   Copyright (C) 88, 91, 1995-2002 Free Software Foundation, Inc.
 
   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, 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, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
 
/* By [email protected], with rms.
 
   To do:
   * Implement -t CHAR or -t REGEX to specify break characters other
     than newline. */
 
#include <config.h>
 
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>
 
#include "system.h"
#include "closeout.h"
#include "dirname.h"
#include "error.h"
#include "full-write.h"
#include "posixver.h"
#include "safe-read.h"
#include "xstrtol.h"
 
/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "split"
 
#define AUTHORS N_ ("Torbjorn Granlund and Richard M. Stallman")
 
#define DEFAULT_SUFFIX_LENGTH 2
 
/* The name this program was run with. */
char *program_name;
 
/* Base name of output files.  */
static char const *outbase;
 
/* Name of output files.  */
static char *outfile;
 
/* Pointer to the end of the prefix in OUTFILE.
   Suffixes are inserted here.  */
static char *outfile_mid;
 
/* Length of OUTFILE's suffix.  */
static size_t suffix_length = DEFAULT_SUFFIX_LENGTH;
 
/* Name of input file.  May be "-".  */
static char *infile;
 
/* Descriptor on which input file is open.  */
static int input_desc;
 
/* Descriptor on which output file is open.  */
static int output_desc;
 
/* If nonzero, print a diagnostic on standard error just before each
   output file is opened. */
static int verbose;
 
static struct option const longopts[] =
{
  {"bytes", required_argument, NULL, 'b'},
  {"lines", required_argument, NULL, 'l'},
  {"line-bytes", required_argument, NULL, 'C'},
  {"suffix-length", required_argument, NULL, 'a'},
  {"verbose", no_argument, NULL, 2},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};
 
void
usage (int status)
{
  if (status != 0)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
         program_name);
  else
    {
      printf (_("\
Usage: %s [OPTION] [INPUT [PREFIX]]\n\
"),
          program_name);
    fputs (_("\
Output fixed-size pieces of INPUT to PREFIXaa, PREFIXab, ...; default\n\
PREFIX is `x'.  With no INPUT, or when INPUT is -, read standard input.\n\
\n\
"), stdout);
      fputs (_("\
Mandatory arguments to long options are mandatory for short options too.\n\
"), stdout);
      fprintf (stdout, _("\
  -a, --suffix-length=N   use suffixes of length N (default %d)\n\
  -b, --bytes=SIZE        put SIZE bytes per output file\n\
  -C, --line-bytes=SIZE   put at most SIZE bytes of lines per output file\n\
  -l, --lines=NUMBER      put NUMBER lines per output file\n\
"), DEFAULT_SUFFIX_LENGTH);
      fputs (_("\
      --verbose           print a diagnostic to standard error just\n\
                            before each output file is opened\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
SIZE may have a multiplier suffix: b for 512, k for 1K, m for 1 Meg.\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}
 
/* Compute the next sequential output file name and store it into the
   string `outfile'.  */
 
static void
next_file_name (void)
{
  if (! outfile)
    {
      /* Allocate and initialize the first file name.  */
 
      size_t outbase_length = strlen (outbase);
      size_t outfile_length = outbase_length + suffix_length;
      if (outfile_length + 1 < outbase_length)
    xalloc_die ();
      outfile = xmalloc (outfile_length + 1);
      outfile_mid = outfile + outbase_length;
      memcpy (outfile, outbase, outbase_length);
      memset (outfile_mid, 'a', suffix_length);
      outfile[outfile_length] = 0;
 
#if ! _POSIX_NO_TRUNC && HAVE_PATHCONF && defined _PC_NAME_MAX
      /* POSIX requires that if the output file name is too long for
     its directory, `split' must fail without creating any files.
     This must be checked for explicitly on operating systems that
     silently truncate file names.  */
      {
    char *dir = dir_name (outfile);
    long name_max = pathconf (dir, _PC_NAME_MAX);
    if (0 <= name_max && name_max < base_len (base_name (outfile)))
      error (EXIT_FAILURE, ENAMETOOLONG, "%s", outfile);
    free (dir);
      }
#endif
    }
  else
    {
      /* Increment the suffix in place, if possible.  */
 
      char *p;
      for (p = outfile_mid + suffix_length; outfile_mid < p; *--p = 'a')
    if (p[-1]++ != 'z')
      return;
      error (EXIT_FAILURE, 0, _("Output file suffixes exhausted"));
    }
}
 
/* Write BYTES bytes at BP to an output file.
   If NEW_FILE_FLAG is nonzero, open the next output file.
   Otherwise add to the same output file already in use.  */
 
static void
cwrite (int new_file_flag, const char *bp, int bytes)
{
  if (new_file_flag)
    {
      if (output_desc >= 0 && close (output_desc) < 0)
    error (EXIT_FAILURE, errno, "%s", outfile);
 
      next_file_name ();
      if (verbose)
    fprintf (stderr, _("creating file `%s'\n"), outfile);
      output_desc = open (outfile,
              O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666);
      if (output_desc < 0)
    error (EXIT_FAILURE, errno, "%s", outfile);
    }
  if (full_write (output_desc, bp, bytes) != (size_t) bytes)
    error (EXIT_FAILURE, errno, "%s", outfile);
}
 
/* Read NCHARS bytes from the input file into BUF.
   Return the number of bytes successfully read.
   If this is less than NCHARS, do not call `stdread' again.  */
 
static int
stdread (char *buf, int nchars)
{
  int n_read;
  int to_be_read = nchars;
 
  while (to_be_read)
    {
      n_read = safe_read (input_desc, buf, to_be_read);
      if (n_read < 0)
    return -1;
      if (n_read == 0)
    break;
      to_be_read -= n_read;
      buf += n_read;
    }
  return nchars - to_be_read;
}
 
/* Split into pieces of exactly NCHARS bytes.
   Use buffer BUF, whose size is BUFSIZE.  */
 
static void
bytes_split (int nchars, char *buf, int bufsize)
{
  int n_read;
  int new_file_flag = 1;
  int to_read;
  int to_write = nchars;
  char *bp_out;
 
  do
    {
      n_read = stdread (buf, bufsize);
      if (n_read < 0)
        error (EXIT_FAILURE, errno, "%s", infile);
      bp_out = buf;
      to_read = n_read;
      for (;;)
    {
      if (to_read < to_write)
        {
          if (to_read)    /* do not write 0 bytes! */
        {
          cwrite (new_file_flag, bp_out, to_read);
          to_write -= to_read;
          new_file_flag = 0;
        }
          break;
        }
      else
        {
          cwrite (new_file_flag, bp_out, to_write);
          bp_out += to_write;
          to_read -= to_write;
          new_file_flag = 1;
          to_write = nchars;
        }
    }
    }
  while (n_read == bufsize);
}
 
/* Split into pieces of exactly NLINES lines.
   Use buffer BUF, whose size is BUFSIZE.  */
 
static void
lines_split (int nlines, char *buf, int bufsize)
{
  int n_read;
  char *bp, *bp_out, *eob;
  int new_file_flag = 1;
  int n = 0;
 
  do
    {
      n_read = stdread (buf, bufsize);
      if (n_read < 0)
    error (EXIT_FAILURE, errno, "%s", infile);
      bp = bp_out = buf;
      eob = bp + n_read;
      *eob = '\n';
      for (;;)
    {
      while (*bp++ != '\n')
        ;            /* this semicolon takes most of the time */
      if (bp > eob)
        {
          if (eob != bp_out) /* do not write 0 bytes! */
        {
          cwrite (new_file_flag, bp_out, eob - bp_out);
          new_file_flag = 0;
        }
          break;
        }
      else
        if (++n >= nlines)
          {
        cwrite (new_file_flag, bp_out, bp - bp_out);
        bp_out = bp;
        new_file_flag = 1;
        n = 0;
          }
    }
    }
  while (n_read == bufsize);
}
 
 
/* Split into pieces that are as large as possible while still not more
   than NCHARS bytes, and are split on line boundaries except
   where lines longer than NCHARS bytes occur. */
 
static void
line_bytes_split (int nchars)
{
  int n_read;
  char *bp;
  int eof = 0;
  int n_buffered = 0;
  char *buf = (char *) xmalloc (nchars);
 
  do
    {
      /* Fill up the full buffer size from the input file.  */
 
      n_read = stdread (buf + n_buffered, nchars - n_buffered);
      if (n_read < 0)
    error (EXIT_FAILURE, errno, "%s", infile);
 
      n_buffered += n_read;
      if (n_buffered != nchars)
    eof = 1;
 
      /* Find where to end this chunk.  */
      bp = buf + n_buffered;
      if (n_buffered == nchars)
    {
      while (bp > buf && bp[-1] != '\n')
        bp--;
    }
 
      /* If chunk has no newlines, use all the chunk.  */
      if (bp == buf)
    bp = buf + n_buffered;
 
      /* Output the chars as one output file.  */
      cwrite (1, buf, bp - buf);
 
      /* Discard the chars we just output; move rest of chunk
     down to be the start of the next chunk.  Source and
     destination probably overlap.  */
      n_buffered -= bp - buf;
      if (n_buffered > 0)
    memmove (buf, bp, n_buffered);
    }
  while (!eof);
  free (buf);
}
 
#define FAIL_ONLY_ONE_WAY()                    \
  do                                \
    {                                \
      error (0, 0, _("cannot split in more than one way"));    \
      usage (EXIT_FAILURE);                    \
    }                                \
  while (0)
 
int
main (int argc, char **argv)
{
  struct stat stat_buf;
  int num;            /* numeric argument from command line */
  enum
    {
      type_undef, type_bytes, type_byteslines, type_lines, type_digits
    } split_type = type_undef;
  int in_blk_size;        /* optimal block size of input file device */
  char *buf;            /* file i/o buffer */
  int accum = 0;
  int c;
  int digits_optind = 0;
 
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);
 
  atexit (close_stdout);
 
  /* Parse command line options.  */
 
  infile = "-";
  outbase = "x";
 
  while (1)
    {
      /* This is the argv-index of the option we will read next.  */
      int this_optind = optind ? optind : 1;
      long int tmp_long;
 
      c = getopt_long (argc, argv, "0123456789C:a:b:l:", longopts, NULL);
      if (c == -1)
    break;
 
      switch (c)
    {
    case 0:
      break;
 
    case 'a':
      {
        unsigned long tmp;
        if (xstrtoul (optarg, NULL, 10, &tmp, "") != LONGINT_OK
        || SIZE_MAX < tmp)
          {
        error (0, 0, _("%s: invalid suffix length"), optarg);
        usage (EXIT_FAILURE);
          }
        suffix_length = tmp;
      }
      break;
 
    case 'b':
      if (split_type != type_undef)
        FAIL_ONLY_ONE_WAY ();
      split_type = type_bytes;
      if (xstrtol (optarg, NULL, 10, &tmp_long, "bkm") != LONGINT_OK
          || tmp_long < 0 || tmp_long > INT_MAX)
        {
          error (0, 0, _("%s: invalid number of bytes"), optarg);
          usage (EXIT_FAILURE);
        }
      accum = (int) tmp_long;
      break;
 
    case 'l':
      if (split_type != type_undef)
        FAIL_ONLY_ONE_WAY ();
      split_type = type_lines;
      if (xstrtol (optarg, NULL, 10, &tmp_long, "") != LONGINT_OK
          || tmp_long < 0 || tmp_long > INT_MAX)
        {
          error (0, 0, _("%s: invalid number of lines"), optarg);
          usage (EXIT_FAILURE);
        }
      accum = (int) tmp_long;
      break;
 
    case 'C':
      if (split_type != type_undef)
        FAIL_ONLY_ONE_WAY ();
      split_type = type_byteslines;
      if (xstrtol (optarg, NULL, 10, &tmp_long, "bkm") != LONGINT_OK
          || tmp_long < 0 ||  tmp_long > INT_MAX)
        {
          error (0, 0, _("%s: invalid number of bytes"), optarg);
          usage (EXIT_FAILURE);
        }
      accum = (int) tmp_long;
      break;
 
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      if (split_type != type_undef && split_type != type_digits)
        FAIL_ONLY_ONE_WAY ();
      if (digits_optind != 0 && digits_optind != this_optind)
        accum = 0;        /* More than one number given; ignore other. */
      digits_optind = this_optind;
      split_type = type_digits;
      accum = accum * 10 + c - '0';
      break;
 
    case 2:
      verbose = 1;
      break;
 
    case_GETOPT_HELP_CHAR;
 
    case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 
    default:
      usage (EXIT_FAILURE);
    }
    }
 
  if (digits_optind && 200112 <= posix2_version ()
      && getenv ("POSIXLY_CORRECT"))
    {
      error (0, 0, _("`-%d' option is obsolete; use `-l %d'"), accum, accum);
      usage (EXIT_FAILURE);
    }
 
  /* Handle default case.  */
  if (split_type == type_undef)
    {
      split_type = type_lines;
      accum = 1000;
    }
 
  if (accum < 1)
    {
      error (0, 0, _("invalid number"));
      usage (EXIT_FAILURE);
    }
  num = accum;
 
  /* Get out the filename arguments.  */
 
  if (optind < argc)
    infile = argv[optind++];
 
  if (optind < argc)
    outbase = argv[optind++];
 
  if (optind < argc)
    {
      error (0, 0, _("too many arguments"));
      usage (EXIT_FAILURE);
    }
 
  /* Open the input file.  */
  if (STREQ (infile, "-"))
    input_desc = 0;
  else
    {
      input_desc = open (infile, O_RDONLY);
      if (input_desc < 0)
    error (EXIT_FAILURE, errno, "%s", infile);
    }
  /* Binary I/O is safer when bytecounts are used.  */
  SET_BINARY (input_desc);
 
  /* No output file is open now.  */
  output_desc = -1;
 
  /* Get the optimal block size of input device and make a buffer.  */
 
  if (fstat (input_desc, &stat_buf) < 0)
    error (EXIT_FAILURE, errno, "%s", infile);
  in_blk_size = ST_BLKSIZE (stat_buf);
 
  buf = xmalloc (in_blk_size + 1);
 
  switch (split_type)
    {
    case type_digits:
    case type_lines:
      lines_split (num, buf, in_blk_size);
      break;
 
    case type_bytes:
      bytes_split (num, buf, in_blk_size);
      break;
 
    case type_byteslines:
      line_bytes_split (num);
      break;
 
    default:
      abort ();
    }
 
  if (close (input_desc) < 0)
    error (EXIT_FAILURE, errno, "%s", infile);
  if (output_desc >= 0 && close (output_desc) < 0)
    error (EXIT_FAILURE, errno, "%s", outfile);
 
  exit (EXIT_SUCCESS);
}
 
相关阅读 更多 +
排行榜 更多 +
我的宠物医生世界

我的宠物医生世界

休闲益智 下载
恐怖的小丑最新版

恐怖的小丑最新版

休闲益智 下载
蛋糕赛道

蛋糕赛道

休闲益智 下载