simulate Grep command in Unix using C

If any body could program this in C, plz help me out.


Simulate the grep command in Unix. Make use of command line arguments to accept filenames as Input maximum 4 minimum 2. In the files search for a specific pattern. If the pattern is available then print the file in which it is available & print the lines in which the pattern is available. Ignore case while searching.

thanx
laxmi

I doubt anyone here will do your homework for you. But you will be able to get help with *your* coding. Try it, and post some code here when you get stuck.

your're near

pseudocode:

Code:

---

open file
while file's not at the end
  get a line
  does 'blah' exist in the line?
  if yes, print the line
repeat

---

Sorry for the long code.
Note to Moderators: Remove code if you wish.

Code:

---

/* grep.c - main driver file for grep.
  Copyright 1992, 1997-1999, 2000 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.  */

/* Written July 1992 by Mike Haertel.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#if defined(HAVE_MMAP)
# include <sys/mman.h>
#endif
#if defined(HAVE_SETRLIMIT)
# include <sys/time.h>
# include <sys/resource.h>
#endif
#include <stdio.h>
#include "system.h"
#include "getopt.h"
#include "getpagesize.h"
#include "grep.h"
#include "savedir.h"
#include "xstrtol.h"
#include "xalloc.h"
#include "error.h"
#include "exclude.h"
#include "closeout.h"

#undef MAX
#define MAX(A,B) ((A) > (B) ? (A) : (B))

struct stats
{
  struct stats const *parent;
  struct stat stat;
};

/* base of chain of stat buffers, used to detect directory loops */
static struct stats stats_base;

/* if non-zero, display usage information and exit */
static int show_help;

/* If non-zero, print the version on standard output and exit.  */
static int show_version;

/* If nonzero, suppress diagnostics for nonexistent or unreadable files.  */
static int suppress_errors;

/* If nonzero, use mmap if possible.  */
static int mmap_option;

/* If nonzero, use grep_color marker.  */
static int color_option;

/* If nonzero, show only the part of a line matching the expression. */
static int only_matching;

/* The color string used.  The user can overwrite it using the environment
  variable GREP_COLOR.  The default is to print red.  */
static const char *grep_color = "01;31";

static struct exclude *excluded_patterns;
static struct exclude *included_patterns;
/* Short options.  */
static char const short_options[] =
"0123456789A:B:C:D:EFGHIPUVX:abcd:e:f:hiKLlm:noqRrsuvwxyZz";

/* Non-boolean long options that have no corresponding short equivalents.  */
enum
{
  BINARY_FILES_OPTION = CHAR_MAX + 1,
  COLOR_OPTION,
  INCLUDE_OPTION,
  EXCLUDE_OPTION,
  EXCLUDE_FROM_OPTION,
  LINE_BUFFERED_OPTION,
  LABEL_OPTION
};

/* Long options equivalences. */
static struct option const long_options[] =
{
  {"after-context", required_argument, NULL, 'A'},
  {"basic-regexp", no_argument, NULL, 'G'},
  {"before-context", required_argument, NULL, 'B'},
  {"binary-files", required_argument, NULL, BINARY_FILES_OPTION},
  {"byte-offset", no_argument, NULL, 'b'},
  {"context", required_argument, NULL, 'C'},
  {"color", optional_argument, NULL, COLOR_OPTION},
  {"colour", optional_argument, NULL, COLOR_OPTION},
  {"count", no_argument, NULL, 'c'},
  {"devices", required_argument, NULL, 'D'},
  {"directories", required_argument, NULL, 'd'},
  {"extended-regexp", no_argument, NULL, 'E'},
  {"exclude", required_argument, NULL, EXCLUDE_OPTION},
  {"exclude-from", required_argument, NULL, EXCLUDE_FROM_OPTION},
  {"file", required_argument, NULL, 'f'},
  {"files-with-matches", no_argument, NULL, 'l'},
  {"files-without-match", no_argument, NULL, 'L'},
  {"fixed-regexp", no_argument, NULL, 'F'},
  {"fixed-strings", no_argument, NULL, 'F'},
  {"help", no_argument, &show_help, 1},
  {"include", required_argument, NULL, INCLUDE_OPTION},
  {"ignore-case", no_argument, NULL, 'i'},
  {"label", required_argument, NULL, LABEL_OPTION},
  {"line-buffered", no_argument, NULL, LINE_BUFFERED_OPTION},
  {"line-number", no_argument, NULL, 'n'},
  {"line-regexp", no_argument, NULL, 'x'},
  {"max-count", required_argument, NULL, 'm'},
  {"mmap", no_argument, &mmap_option, 1},
  {"no-filename", no_argument, NULL, 'h'},
  {"no-messages", no_argument, NULL, 's'},
  {"null", no_argument, NULL, 'Z'},
  {"null-data", no_argument, NULL, 'z'},
  {"only-matching", no_argument, NULL, 'o'},
  {"perl-regexp", no_argument, NULL, 'P'},
  {"quiet", no_argument, NULL, 'q'},
  {"recursive", no_argument, NULL, 'r'},
  {"recursive", no_argument, NULL, 'R'},
  {"regexp", required_argument, NULL, 'e'},
  {"invert-match", no_argument, NULL, 'v'},
  {"silent", no_argument, NULL, 'q'},
  {"text", no_argument, NULL, 'a'},
  {"binary", no_argument, NULL, 'U'},
  {"unix-byte-offsets", no_argument, NULL, 'u'},
  {"version", no_argument, NULL, 'V'},
  {"with-filename", no_argument, NULL, 'H'},
  {"word-regexp", no_argument, NULL, 'w'},
  {0, 0, 0, 0}
};

/* Define flags declared in grep.h. */
int match_icase;
int match_words;
int match_lines;
unsigned char eolbyte;

/* For error messages. */
/* The name the program was run with, stripped of any leading path. */
char *program_name;
static char const *filename;
static int errseen;

/* How to handle directories.  */
static enum
  {
    READ_DIRECTORIES,
    RECURSE_DIRECTORIES,
    SKIP_DIRECTORIES
  } directories = READ_DIRECTORIES;

/* How to handle devices. */
static enum
  {
    READ_DEVICES,
    SKIP_DEVICES
  } devices = READ_DEVICES;

static int grepdir PARAMS ((char const *, struct stats const *));
#if defined(HAVE_DOS_FILE_CONTENTS)
static inline int undossify_input PARAMS ((register char *, size_t));
#endif

/* Functions we'll use to search. */
static void (*compile) PARAMS ((char const *, size_t));
static size_t (*execute) PARAMS ((char const *, size_t, size_t *, int));

/* Like error, but suppress the diagnostic if requested.  */
static void
suppressible_error (char const *mesg, int errnum)
{
  if (! suppress_errors)
    error (0, errnum, "%s", mesg);
  errseen = 1;
}

/* Convert STR to a positive integer, storing the result in *OUT.
  STR must be a valid context length argument; report an error if it
  isn't.  */
static void
context_length_arg (char const *str, int *out)
{
  uintmax_t value;
  if (! (xstrtoumax (str, 0, 10, &value, "") == LONGINT_OK
        && 0 <= (*out = value)
        && *out == value))
    {
      error (2, 0, "%s: %s\n", str, _("invalid context length argument"));
    }
}


/* Hairy buffering mechanism for grep.  The intent is to keep
  all reads aligned on a page boundary and multiples of the
  page size, unless a read yields a partial page.  */

static char *buffer;                /* Base of buffer. */
static size_t bufalloc;                /* Allocated buffer size, counting slop. */
#define INITIAL_BUFSIZE 32768        /* Initial buffer size, not counting slop. */
static int bufdesc;                /* File descriptor. */
static char *bufbeg;                /* Beginning of user-visible stuff. */
static char *buflim;                /* Limit of user-visible stuff. */
static size_t pagesize;                /* alignment of memory pages */
static off_t bufoffset;                /* Read offset; defined on regular files.  */
static off_t after_last_match;        /* Pointer after last matching line that
                                  would have been output if we were
                                  outputting characters. */

#if defined(HAVE_MMAP)
static int bufmapped;                /* True if buffer is memory-mapped.  */
static off_t initial_bufoffset;        /* Initial value of bufoffset. */
#else
# define bufmapped 0
#endif

/* Return VAL aligned to the next multiple of ALIGNMENT.  VAL can be
  an integer or a pointer.  Both args must be free of side effects.  */
#define ALIGN_TO(val, alignment) \
  ((size_t) (val) % (alignment) == 0 \
  ? (val) \
  : (val) + ((alignment) - (size_t) (val) % (alignment)))

/* Reset the buffer for a new file, returning zero if we should skip it.
  Initialize on the first time through. */
static int
reset (int fd, char const *file, struct stats *stats)
{
  if (! pagesize)
    {
      pagesize = getpagesize ();
      if (pagesize == 0 || 2 * pagesize + 1 <= pagesize)
        abort ();
      bufalloc = ALIGN_TO (INITIAL_BUFSIZE, pagesize) + pagesize + 1;
      buffer = xmalloc (bufalloc);
    }

  bufbeg = buflim = ALIGN_TO (buffer + 1, pagesize);
  bufbeg[-1] = eolbyte;
  bufdesc = fd;

  if (fstat (fd, &stats->stat) != 0)
    {
      error (0, errno, "fstat");
      return 0;
    }
  if (directories == SKIP_DIRECTORIES && S_ISDIR (stats->stat.st_mode))
    return 0;
#ifndef DJGPP
  if (devices == SKIP_DEVICES && (S_ISCHR(stats->stat.st_mode) || S_ISBLK(stats->stat.st_mode) || S_ISSOCK(stats->stat.st_mode)))
#else
  if (devices == SKIP_DEVICES && (S_ISCHR(stats->stat.st_mode) || S_ISBLK(stats->stat.st_mode)))
#endif
    return 0;
  if (S_ISREG (stats->stat.st_mode))
    {
      if (file)
        bufoffset = 0;
      else
        {
          bufoffset = lseek (fd, 0, SEEK_CUR);
          if (bufoffset < 0)
            {
              error (0, errno, "lseek");
              return 0;
            }
        }
#if defined(HAVE_MMAP)
      initial_bufoffset = bufoffset;
      bufmapped = mmap_option && bufoffset % pagesize == 0;
#endif
    }
  else
    {
#if defined(HAVE_MMAP)
      bufmapped = 0;
#endif
    }
  return 1;
}

/* Read new stuff into the buffer, saving the specified
  amount of old stuff.  When we're done, 'bufbeg' points
  to the beginning of the buffer contents, and 'buflim'
  points just after the end.  Return zero if there's an error.  */
static int
fillbuf (size_t save, struct stats const *stats)
{
  size_t fillsize = 0;
  int cc = 1;
  char *readbuf;
  size_t readsize;

  /* Offset from start of buffer to start of old stuff
    that we want to save.  */
  size_t saved_offset = buflim - save - buffer;

  if (pagesize <= buffer + bufalloc - buflim)
    {
      readbuf = buflim;
      bufbeg = buflim - save;
    }
  else
    {
      size_t minsize = save + pagesize;
      size_t newsize;
      size_t newalloc;
      char *newbuf;

      /* Grow newsize until it is at least as great as minsize.  */
      for (newsize = bufalloc - pagesize - 1; newsize < minsize; newsize *= 2)
        if (newsize * 2 < newsize || newsize * 2 + pagesize + 1 < newsize * 2)
          xalloc_die ();

      /* Try not to allocate more memory than the file size indicates,
        as that might cause unnecessary memory exhaustion if the file
        is large.  However, do not use the original file size as a
        heuristic if we've already read past the file end, as most
        likely the file is growing.  */
      if (S_ISREG (stats->stat.st_mode))
        {
          off_t to_be_read = stats->stat.st_size - bufoffset;
          off_t maxsize_off = save + to_be_read;
          if (0 <= to_be_read && to_be_read <= maxsize_off
              && maxsize_off == (size_t) maxsize_off
              && minsize <= (size_t) maxsize_off
              && (size_t) maxsize_off < newsize)
            newsize = maxsize_off;
        }

      /* Add enough room so that the buffer is aligned and has room
        for byte sentinels fore and aft.  */
      newalloc = newsize + pagesize + 1;

      newbuf = bufalloc < newalloc ? xmalloc (bufalloc = newalloc) : buffer;
      readbuf = ALIGN_TO (newbuf + 1 + save, pagesize);
      bufbeg = readbuf - save;
      memmove (bufbeg, buffer + saved_offset, save);
      bufbeg[-1] = eolbyte;
      if (newbuf != buffer)
        {
          free (buffer);
          buffer = newbuf;
        }
    }

  readsize = buffer + bufalloc - readbuf;
  readsize -= readsize % pagesize;

#if defined(HAVE_MMAP)
  if (bufmapped)
    {
      size_t mmapsize = readsize;

      /* Don't mmap past the end of the file; some hosts don't allow this.
        Use `read' on the last page.  */
      if (stats->stat.st_size - bufoffset < mmapsize)
        {
          mmapsize = stats->stat.st_size - bufoffset;
          mmapsize -= mmapsize % pagesize;
        }

      if (mmapsize
          && (mmap ((caddr_t) readbuf, mmapsize,
                    PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_FIXED,
                    bufdesc, bufoffset)
              != (caddr_t) -1))
        {
          /* Do not bother to use madvise with MADV_SEQUENTIAL or
            MADV_WILLNEED on the mmapped memory.  One might think it
            would help, but it slows us down about 30% on SunOS 4.1.  */
          fillsize = mmapsize;
        }
      else
        {
          /* Stop using mmap on this file.  Synchronize the file
            offset.  Do not warn about mmap failures.  On some hosts
            (e.g. Solaris 2.5) mmap can fail merely because some
            other process has an advisory read lock on the file.
            There's no point alarming the user about this misfeature.  */
          bufmapped = 0;
          if (bufoffset != initial_bufoffset
              && lseek (bufdesc, bufoffset, SEEK_SET) < 0)
            {
              error (0, errno, "lseek");
              cc = 0;
            }
        }
    }
#endif /*HAVE_MMAP*/

  if (! fillsize)
    {
      ssize_t bytesread;
      while ((bytesread = read (bufdesc, readbuf, readsize)) < 0
            && errno == EINTR)
        continue;
      if (bytesread < 0)
        cc = 0;
      else
        fillsize = bytesread;
    }

  bufoffset += fillsize;
#if defined(HAVE_DOS_FILE_CONTENTS)
  if (fillsize)
    fillsize = undossify_input (readbuf, fillsize);
#endif
  buflim = readbuf + fillsize;
  return cc;
}

/* Flags controlling the style of output. */
static enum
{
  BINARY_BINARY_FILES,
  TEXT_BINARY_FILES,
  WITHOUT_MATCH_BINARY_FILES
} binary_files;                /* How to handle binary files.  */

static int filename_mask;        /* If zero, output nulls after filenames.  */
static int out_quiet;                /* Suppress all normal output. */
static int out_invert;                /* Print nonmatching stuff. */
static int out_file;                /* Print filenames. */
static int out_line;                /* Print line numbers. */
static int out_byte;                /* Print byte offsets. */
static int out_before;                /* Lines of leading context. */
static int out_after;                /* Lines of trailing context. */
static int count_matches;        /* Count matching lines.  */
static int list_files;                /* List matching files.  */
static int no_filenames;        /* Suppress file names.  */
static off_t max_count;                /* Stop after outputting this many
                                  lines from an input file.  */
static int line_buffered;      /* If nonzero, use line buffering, i.e.
                                  fflush everyline out.  */
static char *label = NULL;      /* Fake filename for stdin */


/* Internal variables to keep track of byte count, context, etc. */
static uintmax_t totalcc;        /* Total character count before bufbeg. */
static char const *lastnl;        /* Pointer after last newline counted. */
static char const *lastout;        /* Pointer after last character output;
                                  NULL if no character has been output
                                  or if it's conceptually before bufbeg. */
static uintmax_t totalnl;        /* Total newline count before lastnl. */
static off_t outleft;                /* Maximum number of lines to be output.  */
static int pending;                /* Pending lines of output.
                                  Always kept 0 if out_quiet is true.  */
static int done_on_match;        /* Stop scanning file on first match.  */
static int exit_on_match;        /* Exit on first match.  */

#if defined(HAVE_DOS_FILE_CONTENTS)
# include "dosbuf.c"
#endif

/* Add two numbers that count input bytes or lines, and report an
  error if the addition overflows.  */
static uintmax_t
add_count (uintmax_t a, uintmax_t b)
{
  uintmax_t sum = a + b;
  if (sum < a)
    error (2, 0, _("input is too large to count"));
  return sum;
}

static void
nlscan (char const *lim)
{
  size_t newlines = 0;
  char const *beg;
  for (beg = lastnl; beg != lim; beg = memchr (beg, eolbyte, lim - beg), beg++)
    newlines++;
  totalnl = add_count (totalnl, newlines);
  lastnl = lim;
}

/* Print a byte offset, followed by a character separator.  */
static void
print_offset_sep (uintmax_t pos, char sep)
{
  /* Do not rely on printf to print pos, since uintmax_t may be longer
    than long, and long long is not portable.  */

  char buf[sizeof pos * CHAR_BIT];
  char *p = buf + sizeof buf - 1;
  *p = sep;

  do
    *--p = '0' + pos % 10;
  while ((pos /= 10) != 0);

  fwrite (p, 1, buf + sizeof buf - p, stdout);
}

static void
prline (char const *beg, char const *lim, int sep)
{
  if (out_file)
    printf ("%s%c", filename, sep & filename_mask);
  if (out_line)
    {
      nlscan (beg);
      totalnl = add_count (totalnl, 1);
      print_offset_sep (totalnl, sep);
      lastnl = lim;
    }
  if (out_byte)
    {
      uintmax_t pos = add_count (totalcc, beg - bufbeg);
#if defined(HAVE_DOS_FILE_CONTENTS)
      pos = dossified_pos (pos);
#endif
      print_offset_sep (pos, sep);
    }
  if (only_matching)
    {
      size_t match_size;
      size_t match_offset;
      while ((match_offset = (*execute) (beg, lim - beg, &match_size, 1))
          != (size_t) -1)
        {
          char const *b = beg + match_offset;
          if (b == lim)
            break;
          if(color_option)
            printf("\33[%sm", grep_color);
          fwrite(b, sizeof (char), match_size, stdout);
          if(color_option)
            fputs("\33[00m", stdout);
          fputs("\n", stdout);
          beg = b + match_size;
        }
      lastout = lim;
      if(line_buffered)
        fflush(stdout);
      return;
    }
  if (color_option)
    {
      size_t match_size;
      size_t match_offset;
      if(match_icase)
        {
          /* Yuck, this is tricky */
          char *buf = (char*) xmalloc (lim - beg);
          char *ibeg = buf;
          char *ilim = ibeg + (lim - beg);
          int i;
          for (i = 0; i < lim - beg; i++)
            ibeg[i] = tolower (beg[i]);
          while ((match_offset = (*execute) (ibeg, ilim-ibeg, &match_size, 1))
                != (size_t) -1)
            {
              char const *b = beg + match_offset;
              if (b == lim)
                break;
              fwrite (beg, sizeof (char), match_offset, stdout);
              printf ("\33[%sm", grep_color);
              fwrite (b, sizeof (char), match_size, stdout);
              fputs ("\33[00m", stdout);
              beg = b + match_size;
              ibeg = ibeg + match_offset + match_size;
            }
          fwrite (beg, 1, lim - beg, stdout);
          free (buf);
          lastout = lim;
          return;
        }
      while ((match_offset = (*execute) (beg, lim - beg, &match_size, 1))
            != (size_t) -1)
        {
          char const *b = beg + match_offset;
          /* Avoid matching the empty line at the end of the buffer. */
          if (b == lim)
            break;
          fwrite (beg, sizeof (char), match_offset, stdout);
          printf ("\33[%sm", grep_color);
          fwrite (b, sizeof (char), match_size, stdout);
          fputs ("\33[00m", stdout);
          beg = b + match_size;
        }
    }
  fwrite (beg, 1, lim - beg, stdout);
  if (ferror (stdout))
    error (0, errno, _("writing output"));
  lastout = lim;
  if (line_buffered)
    fflush (stdout);
}

/* Print pending lines of trailing context prior to LIM. Trailing context ends
  at the next matching line when OUTLEFT is 0.  */
static void
prpending (char const *lim)
{
  if (!lastout)
    lastout = bufbeg;
  while (pending > 0 && lastout < lim)
    {
      char const *nl = memchr (lastout, eolbyte, lim - lastout);
      size_t match_size;
      --pending;
      if (outleft
          || (((*execute) (lastout, nl - lastout, &match_size, 0) == (size_t) -1)
              == !out_invert))
        prline (lastout, nl + 1, '-');
      else
        pending = 0;
    }
}

/* Print the lines between BEG and LIM.  Deal with context crap.
  If NLINESP is non-null, store a count of lines between BEG and LIM.  */
static void
prtext (char const *beg, char const *lim, int *nlinesp)
{
  static int used;                /* avoid printing "--" before any output */
  char const *bp, *p;
  char eol = eolbyte;
  int i, n;

  if (!out_quiet && pending > 0)
    prpending (beg);

  p = beg;

  if (!out_quiet)
    {
      /* Deal with leading context crap. */

      bp = lastout ? lastout : bufbeg;
      for (i = 0; i < out_before; ++i)
        if (p > bp)
          do
            --p;
          while (p[-1] != eol);

      /* We only print the "--" separator if our output is
        discontiguous from the last output in the file. */
      if ((out_before || out_after) && used && p != lastout)
        puts ("--");

      while (p < beg)
        {
          char const *nl = memchr (p, eol, beg - p);
          nl++;
          prline (p, nl, '-');
          p = nl;
        }
    }

  if (nlinesp)
    {
      /* Caller wants a line count. */
      for (n = 0; p < lim && n < outleft; n++)
        {
          char const *nl = memchr (p, eol, lim - p);
          nl++;
          if (!out_quiet)
            prline (p, nl, ':');
          p = nl;
        }
      *nlinesp = n;

      /* relying on it that this function is never called when outleft = 0.  */
      after_last_match = bufoffset - (buflim - p);
    }
  else
    if (!out_quiet)
      prline (beg, lim, ':');

  pending = out_quiet ? 0 : out_after;
  used = 1;
}

/* Scan the specified portion of the buffer, matching lines (or
  between matching lines if OUT_INVERT is true).  Return a count of
  lines printed. */
static int
grepbuf (char const *beg, char const *lim)
{
  int nlines, n;
  register char const *p;
  size_t match_offset;
  size_t match_size;

  nlines = 0;
  p = beg;
  while ((match_offset = (*execute) (p, lim - p, &match_size, 0)) != (size_t) -1)
    {
      char const *b = p + match_offset;
      char const *endp = b + match_size;
      /* Avoid matching the empty line at the end of the buffer. */
      if (b == lim)
        break;
      if (!out_invert)
        {
          prtext (b, endp, (int *) 0);
          nlines++;
          outleft--;
          if (!outleft || done_on_match)
            {
              if (exit_on_match)
                exit (0);
              after_last_match = bufoffset - (buflim - endp);
              return nlines;
            }
        }
      else if (p < b)
        {
          prtext (p, b, &n);
          nlines += n;
          outleft -= n;
          if (!outleft)
            return nlines;
        }
      p = endp;
    }
  if (out_invert && p < lim)
    {
      prtext (p, lim, &n);
      nlines += n;
      outleft -= n;
    }
  return nlines;
}

/* Search a given file.  Normally, return a count of lines printed;
  but if the file is a directory and we search it recursively, then
  return -2 if there was a match, and -1 otherwise.  */
static int
grep (int fd, char const *file, struct stats *stats)
{
  int nlines, i;
  int not_text;
  size_t residue, save;
  char oldc;
  char *beg;
  char *lim;
  char eol = eolbyte;

  if (!reset (fd, file, stats))
    return 0;

  if (file && directories == RECURSE_DIRECTORIES
      && S_ISDIR (stats->stat.st_mode))
    {
      /* Close fd now, so that we don't open a lot of file descriptors
        when we recurse deeply.  */
      if (close (fd) != 0)
        error (0, errno, "%s", file);
      return grepdir (file, stats) - 2;
    }

  totalcc = 0;
  lastout = 0;
  totalnl = 0;
  outleft = max_count;
  after_last_match = 0;
  pending = 0;

  nlines = 0;
  residue = 0;
  save = 0;

  if (! fillbuf (save, stats))
    {
      if (! is_EISDIR (errno, file))
        suppressible_error (filename, errno);
      return 0;
    }

  not_text = (((binary_files == BINARY_BINARY_FILES && !out_quiet)
              || binary_files == WITHOUT_MATCH_BINARY_FILES)
              && memchr (bufbeg, eol ? '\0' : '\200', buflim - bufbeg));
  if (not_text && binary_files == WITHOUT_MATCH_BINARY_FILES)
    return 0;
  done_on_match += not_text;
  out_quiet += not_text;

  for (;;)
    {
      lastnl = bufbeg;
      if (lastout)
        lastout = bufbeg;

      beg = bufbeg + save;

      /* no more data to scan (eof) except for maybe a residue -> break */
      if (beg == buflim)
        break;

      /* Determine new residue (the length of an incomplete line at the end of
        the buffer, 0 means there is no incomplete last line).  */
      oldc = beg[-1];
      beg[-1] = eol;
      for (lim = buflim; lim[-1] != eol; lim--)
        continue;
      beg[-1] = oldc;
      if (lim == beg)
        lim = beg - residue;
      beg -= residue;
      residue = buflim - lim;

      if (beg < lim)
        {
          if (outleft)
            nlines += grepbuf (beg, lim);
          if (pending)
            prpending (lim);
          if((!outleft && !pending) || (nlines && done_on_match && !out_invert))
            goto finish_grep;
        }

      /* The last OUT_BEFORE lines at the end of the buffer will be needed as
        leading context if there is a matching line at the begin of the
        next data. Make beg point to their begin.  */
      i = 0;
      beg = lim;
      while (i < out_before && beg > bufbeg && beg != lastout)
        {
          ++i;
          do
            --beg;
          while (beg[-1] != eol);
        }

      /* detect if leading context is discontinuous from last printed line.  */
      if (beg != lastout)
        lastout = 0;

      /* Handle some details and read more data to scan.  */
      save = residue + lim - beg;
      if (out_byte)
        totalcc = add_count (totalcc, buflim - bufbeg - save);
      if (out_line)
        nlscan (beg);
      if (! fillbuf (save, stats))
        {
          if (! is_EISDIR (errno, file))
            suppressible_error (filename, errno);
          goto finish_grep;
        }
    }
  if (residue)
    {
      *buflim++ = eol;
      if (outleft)
        nlines += grepbuf (bufbeg + save - residue, buflim);
      if (pending)
        prpending (buflim);
    }

 finish_grep:
  done_on_match -= not_text;
  out_quiet -= not_text;
  if ((not_text & ~out_quiet) && nlines != 0)
    printf (_("Binary file %s matches\n"), filename);
  return nlines;
}

static int
grepfile (char const *file, struct stats *stats)
{
  int desc;
  int count;
  int status;

  if (! file)
    {
      desc = 0;
      filename = label ? label : _("(standard input)");
    }
  else
    {
      while ((desc = open (file, O_RDONLY)) < 0 && errno == EINTR)
        continue;

      if (desc < 0)
        {
          int e = errno;

          if (is_EISDIR (e, file) && directories == RECURSE_DIRECTORIES)
            {
              if (stat (file, &stats->stat) != 0)
                {
                  error (0, errno, "%s", file);
                  return 1;
                }

              return grepdir (file, stats);
            }

          if (!suppress_errors)
            {
              if (directories == SKIP_DIRECTORIES)
                switch (e)
                  {
#if defined(EISDIR)
                  case EISDIR:
                    return 1;
#endif
                  case EACCES:
                    /* When skipping directories, don't worry about
                      directories that can't be opened.  */
                    if (isdir (file))
                      return 1;
                    break;
                  }
            }

          suppressible_error (file, e);
          return 1;
        }

      filename = file;
    }

#if defined(SET_BINARY)
  /* Set input to binary mode.  Pipes are simulated with files
    on DOS, so this includes the case of "foo | grep bar".  */
  if (!isatty (desc))
    SET_BINARY (desc);
#endif

  count = grep (desc, file, stats);
  if (count < 0)
    status = count + 2;
  else
    {
      if (count_matches)
        {
          if (out_file)
            printf ("%s%c", filename, ':' & filename_mask);
          printf ("%d\n", count);
        }

      status = !count;
      if (list_files == 1 - 2 * status)
        printf ("%s%c", filename, '\n' & filename_mask);

      if (! file)
        {
          off_t required_offset = outleft ? bufoffset : after_last_match;
          if ((bufmapped || required_offset != bufoffset)
              && lseek (desc, required_offset, SEEK_SET) < 0
              && S_ISREG (stats->stat.st_mode))
            error (0, errno, "%s", filename);
        }
      else
        while (close (desc) != 0)
          if (errno != EINTR)
            {
              error (0, errno, "%s", file);
              break;
            }
    }

  return status;
}

static int
grepdir (char const *dir, struct stats const *stats)
{
  int status = 1;
  struct stats const *ancestor;
  char *name_space;

  /* Mingw32 does not support st_ino.  No known working hosts use zero
    for st_ino, so assume that the Mingw32 bug applies if it's zero.  */
  if (stats->stat.st_ino)
    for (ancestor = stats;  (ancestor = ancestor->parent) != 0;  )
      if (ancestor->stat.st_ino == stats->stat.st_ino
          && ancestor->stat.st_dev == stats->stat.st_dev)
        {
          if (!suppress_errors)
            error (0, 0, _("warning: %s: %s\n"), dir,
                  _("recursive directory loop"));
          return 1;
        }

  name_space = savedir (dir, stats->stat.st_size, included_patterns,
                        excluded_patterns);

  if (! name_space)
    {
      if (errno)
        suppressible_error (dir, errno);
      else
        xalloc_die ();
    }
  else
    {
      size_t dirlen = strlen (dir);
      int needs_slash = ! (dirlen == FILESYSTEM_PREFIX_LEN (dir)
                          || IS_SLASH (dir[dirlen - 1]));
      char *file = NULL;
      char const *namep = name_space;
      struct stats child;
      child.parent = stats;
      out_file += !no_filenames;
      while (*namep)
        {
          size_t namelen = strlen (namep);
          file = xrealloc (file, dirlen + 1 + namelen + 1);
          strcpy (file, dir);
          file[dirlen] = '/';
          strcpy (file + dirlen + needs_slash, namep);
          namep += namelen + 1;
          status &= grepfile (file, &child);
        }
      out_file -= !no_filenames;
      if (file)
        free (file);
      free (name_space);
    }

  return status;
}

static void
usage (int status)
{
  if (status != 0)
    {
      fprintf (stderr, _("Usage: %s [OPTION]... PATTERN [FILE]...\n"),
              program_name);
      fprintf (stderr, _("Try `%s --help' for more information.\n"),
              program_name);
    }
  else
    {
      printf (_("Usage: %s [OPTION]... PATTERN [FILE] ...\n"), program_name);
      printf (_("\
Search for PATTERN in each FILE or standard input.\n\
Example: %s -i 'hello world' menu.h main.c\n\
\n\
Regexp selection and interpretation:\n"), program_name);
      printf (_("\
  -E, --extended-regexp    PATTERN is an extended regular expression\n\
  -F, --fixed-strings      PATTERN is a set of newline-separated strings\n\
  -G, --basic-regexp        PATTERN is a basic regular expression\n\
  -P, --perl-regexp        PATTERN is a Perl regular expression\n"));
      printf (_("\
  -e, --regexp=PATTERN      use PATTERN as a regular expression\n\
  -f, --file=FILE          obtain PATTERN from FILE\n\
  -i, --ignore-case        ignore case distinctions\n\
  -w, --word-regexp        force PATTERN to match only whole words\n\
  -x, --line-regexp        force PATTERN to match only whole lines\n\
  -z, --null-data          a data line ends in 0 byte, not newline\n"));
      printf (_("\
\n\
Miscellaneous:\n\
  -s, --no-messages        suppress error messages\n\
  -v, --invert-match        select non-matching lines\n\
  -V, --version            print version information and exit\n\
      --help                display this help and exit\n\
      --mmap                use memory-mapped input if possible\n"));
      printf (_("\
\n\
Output control:\n\
  -m, --max-count=NUM      stop after NUM matches\n\
  -b, --byte-offset        print the byte offset with output lines\n\
  -n, --line-number        print line number with output lines\n\
      --line-buffered      flush output on every line\n\
  -H, --with-filename      print the filename for each match\n\
  -h, --no-filename        suppress the prefixing filename on output\n\
      --label=LABEL        print LABEL as filename for standard input\n\
  -o, --only-matching      show only the part of a line matching PATTERN\n\
  -q, --quiet, --silent    suppress all normal output\n\
      --binary-files=TYPE  assume that binary files are TYPE\n\
                            TYPE is 'binary', 'text', or 'without-match'\n\
  -a, --text                equivalent to --binary-files=text\n\
  -I                        equivalent to --binary-files=without-match\n\
  -d, --directories=ACTION  how to handle directories\n\
                            ACTION is 'read', 'recurse', or 'skip'\n\
  -D, --devices=ACTION      how to handle devices, FIFOs and sockets\n\
                            ACTION is 'read' or 'skip'\n\
  -R, -r, --recursive      equivalent to --directories=recurse\n\
      --include=PATTERN    files that match PATTERN will be examined\n\
      --exclude=PATTERN    files that match PATTERN will be skipped.\n\
      --exclude-from=FILE  files that match PATTERN in FILE will be skipped.\n\
  -L, --files-without-match only print FILE names containing no match\n\
  -l, --files-with-matches  only print FILE names containing matches\n\
  -c, --count              only print a count of matching lines per FILE\n\
  -Z, --null                print 0 byte after FILE name\n"));
      printf (_("\
\n\
Context control:\n\
  -B, --before-context=NUM  print NUM lines of leading context\n\
  -A, --after-context=NUM  print NUM lines of trailing context\n\
  -C, --context=NUM        print NUM lines of output context\n\
  -NUM                      same as --context=NUM\n\
      --color[=WHEN],\n\
      --colour[=WHEN]      use markers to distinguish the matching string\n\
                            WHEN may be `always', `never' or `auto'.\n\
  -U, --binary              do not strip CR characters at EOL (MSDOS)\n\
  -u, --unix-byte-offsets  report offsets as if CRs were not there (MSDOS)\n\
\n\
`egrep' means `grep -E'.  `fgrep' means `grep -F'.\n\
With no FILE, or when FILE is -, read standard input.  If less than\n\
two FILEs given, assume -h.  Exit status is 0 if match, 1 if no match,\n\
and 2 if trouble.\n"));
      printf (_("\nReport bugs to <[email protected]>.\n"));
    }
  exit (status);
}

/* Set the matcher to M, reporting any conflicts.  */
static void
setmatcher (char const *m)
{
  if (matcher && strcmp (matcher, m) != 0)
    error (2, 0, _("conflicting matchers specified"));
  matcher = m;
}

/* Go through the matchers vector and look for the specified matcher.
  If we find it, install it in compile and execute, and return 1.  */
static int
install_matcher (char const *name)
{
  int i;
#if defined(HAVE_SETRLIMIT)
  struct rlimit rlim;
#endif

  for (i = 0; matchers[i].compile; i++)
    if (strcmp (name, matchers[i].name) == 0)
      {
        compile = matchers[i].compile;
        execute = matchers[i].execute;
#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_STACK)
        /* I think every platform needs to do this, so that regex.c
          doesn't oveflow the stack.  The default value of
          `re_max_failures' is too large for some platforms: it needs
          more than 3MB-large stack.

          The test for HAVE_SETRLIMIT should go into `configure'.  */
        if (!getrlimit (RLIMIT_STACK, &rlim))
          {
            long newlim;
            extern long int re_max_failures; /* from regex.c */

            /* Approximate the amount regex.c needs, plus some more.  */
            newlim = re_max_failures * 2 * 20 * sizeof (char *);
            if (newlim > rlim.rlim_max)
              {
                newlim = rlim.rlim_max;
                re_max_failures = newlim / (2 * 20 * sizeof (char *));
              }
            if (rlim.rlim_cur < newlim)
              {
                rlim.rlim_cur = newlim;
                setrlimit (RLIMIT_STACK, &rlim);
              }
          }
#endif
        return 1;
      }
  return 0;
}

/* Find the white-space-separated options specified by OPTIONS, and
  using BUF to store copies of these options, set ARGV[0], ARGV[1],
  etc. to the option copies.  Return the number N of options found.
  Do not set ARGV[N] to NULL.  If ARGV is NULL, do not store ARGV[0]
  etc.  Backslash can be used to escape whitespace (and backslashes).  */
static int
prepend_args (char const *options, char *buf, char **argv)
{
  char const *o = options;
  char *b = buf;
  int n = 0;

  for (;;)
    {
      while (ISSPACE ((unsigned char) *o))
        o++;
      if (!*o)
        return n;
      if (argv)
        argv[n] = b;
      n++;

      do
        if ((*b++ = *o++) == '\\' && *o)
          b[-1] = *o++;
      while (*o && ! ISSPACE ((unsigned char) *o));

      *b++ = '\0';
    }
}

/* Prepend the whitespace-separated options in OPTIONS to the argument
  vector of a main program with argument count *PARGC and argument
  vector *PARGV.  */
static void
prepend_default_options (char const *options, int *pargc, char ***pargv)
{
  if (options)
    {
      char *buf = xmalloc (strlen (options) + 1);
      int prepended = prepend_args (options, buf, (char **) NULL);
      int argc = *pargc;
      char * const *argv = *pargv;
      char **pp = (char **) xmalloc ((prepended + argc + 1) * sizeof *pp);
      *pargc = prepended + argc;
      *pargv = pp;
      *pp++ = *argv++;
      pp += prepend_args (options, buf, pp);
      while ((*pp++ = *argv++))
        continue;
    }
}

/* Get the next non-digit option from ARGC and ARGV.
  Return -1 if there are no more options.
  Process any digit options that were encountered on the way,
  and store the resulting integer into *DEFAULT_CONTEXT.  */
static int
get_nondigit_option (int argc, char *const *argv, int *default_context)
{
  int opt;
  char buf[sizeof (uintmax_t) * CHAR_BIT + 4];
  char *p = buf;

  /* Set buf[0] to anything but '0', for the leading-zero test below.  */
  buf[0] = '\0';

  while (opt = getopt_long (argc, argv, short_options, long_options, NULL),
        '0' <= opt && opt <= '9')
    {
      /* Suppress trivial leading zeros, to avoid incorrect
        diagnostic on strings like 00000000000.  */
      p -= buf[0] == '0';

      *p++ = opt;
      if (p == buf + sizeof buf - 4)
        {
          /* Too many digits.  Append "..." to make context_length_arg
            complain about "X...", where X contains the digits seen
            so far.  */
          strcpy (p, "...");
          p += 3;
          break;
        }
    }
  if (p != buf)
    {
      *p = '\0';
      context_length_arg (buf, default_context);
    }

  return opt;
}

int
main (int argc, char **argv)
{
  char *keys;
  size_t keycc, oldcc, keyalloc;
  int with_filenames;
  int opt, cc, status;
  int default_context;
  FILE *fp;
  extern char *optarg;
  extern int optind;

  initialize_main (&argc, &argv);
  program_name = argv[0];
  if (program_name && strrchr (program_name, '/'))
    program_name = strrchr (program_name, '/') + 1;

  if (!strcmp(program_name, "egrep"))
    setmatcher ("egrep");
  if (!strcmp(program_name, "fgrep"))
    setmatcher ("fgrep");

#if defined(__MSDOS__) || defined(_WIN32)
  /* DOS and MS-Windows use backslashes as directory separators, and usually
    have an .exe suffix.  They also have case-insensitive filesystems.  */
  if (program_name)
    {
      char *p = program_name;
      char *bslash = strrchr (argv[0], '\\');

      if (bslash && bslash >= program_name) /* for mixed forward/backslash case */
        program_name = bslash + 1;
      else if (program_name == argv[0]
              && argv[0][0] && argv[0][1] == ':') /* "c:progname" */
        program_name = argv[0] + 2;

      /* Collapse the letter-case, so `strcmp' could be used hence.  */
      for ( ; *p; p++)
        if (*p >= 'A' && *p <= 'Z')
          *p += 'a' - 'A';

      /* Remove the .exe extension, if any.  */
      if ((p = strrchr (program_name, '.')) && strcmp (p, ".exe") == 0)
        *p = '\0';
    }
#endif

  keys = NULL;
  keycc = 0;
  with_filenames = 0;
  eolbyte = '\n';
  filename_mask = ~0;

  max_count = TYPE_MAXIMUM (off_t);

  /* The value -1 means to use DEFAULT_CONTEXT. */
  out_after = out_before = -1;
  /* Default before/after context: chaged by -C/-NUM options */
  default_context = 0;
  /* Changed by -o option */
  only_matching = 0;

  /* Internationalization. */
#if defined(HAVE_SETLOCALE)
  setlocale (LC_ALL, "");
#endif
#if defined(ENABLE_NLS)
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);
#endif

  atexit (close_stdout);

  prepend_default_options (getenv ("GREP_OPTIONS"), &argc, &argv);

  while ((opt = get_nondigit_option (argc, argv, &default_context)) != -1)
    switch (opt)
      {
      case 'A':
        context_length_arg (optarg, &out_after);
        break;

      case 'B':
        context_length_arg (optarg, &out_before);
        break;

      case 'C':
        /* Set output match context, but let any explicit leading or
          trailing amount specified with -A or -B stand. */
        context_length_arg (optarg, &default_context);
        break;

      case 'D':
        if (strcmp (optarg, "read") == 0)
          devices = READ_DEVICES;
        else if (strcmp (optarg, "skip") == 0)
          devices = SKIP_DEVICES;
        else
          error (2, 0, _("unknown devices method"));
        break;

      case 'E':
        setmatcher ("egrep");
        break;

      case 'F':
        setmatcher ("fgrep");
        break;

      case 'P':
        setmatcher ("perl");
        break;

      case 'G':
        setmatcher ("grep");
        break;

      case 'H':
        with_filenames = 1;
        break;

      case 'I':
        binary_files = WITHOUT_MATCH_BINARY_FILES;
        break;

      case 'U':
#if defined(HAVE_DOS_FILE_CONTENTS)
        dos_use_file_type = DOS_BINARY;
#endif
        break;

      case 'u':
#if defined(HAVE_DOS_FILE_CONTENTS)
        dos_report_unix_offset = 1;
#endif
        break;

      case 'V':
        show_version = 1;
        break;

      case 'X':
        setmatcher (optarg);
        break;

      case 'a':
        binary_files = TEXT_BINARY_FILES;
        break;

      case 'b':
        out_byte = 1;
        break;

      case 'c':
        count_matches = 1;
        break;

      case 'd':
        if (strcmp (optarg, "read") == 0)
          directories = READ_DIRECTORIES;
        else if (strcmp (optarg, "skip") == 0)
          directories = SKIP_DIRECTORIES;
        else if (strcmp (optarg, "recurse") == 0)
          directories = RECURSE_DIRECTORIES;
        else
          error (2, 0, _("unknown directories method"));
        break;

      case 'e':
        cc = strlen (optarg);
        keys = xrealloc (keys, keycc + cc + 1);
        strcpy (&keys[keycc], optarg);
        keycc += cc;
        keys[keycc++] = '\n';
        break;

      case 'f':
        fp = strcmp (optarg, "-") != 0 ? fopen (optarg, "r") : stdin;
        if (!fp)
          error (2, errno, "%s", optarg);
        for (keyalloc = 1; keyalloc <= keycc + 1; keyalloc *= 2)
          ;
        keys = xrealloc (keys, keyalloc);
        oldcc = keycc;
        while (!feof (fp)
              && (cc = fread (keys + keycc, 1, keyalloc - 1 - keycc, fp)) > 0)
          {
            keycc += cc;
            if (keycc == keyalloc - 1)
              keys = xrealloc (keys, keyalloc *= 2);
          }
        if (fp != stdin)
          fclose(fp);
        /* Append final newline if file ended in non-newline. */
        if (oldcc != keycc && keys[keycc - 1] != '\n')
          keys[keycc++] = '\n';
        break;

      case 'h':
        no_filenames = 1;
        break;

      case 'i':
      case 'y':                        /* For old-timers . . . */
        match_icase = 1;
        break;

      case 'L':
        /* Like -l, except list files that don't contain matches.
          Inspired by the same option in Hume's gre. */
        list_files = -1;
        break;

      case 'l':
        list_files = 1;
        break;

      case 'm':
        {
          uintmax_t value;
          switch (xstrtoumax (optarg, 0, 10, &value, ""))
            {
            case LONGINT_OK:
              max_count = value;
              if (0 <= max_count && max_count == value)
                break;
              /* Fall through.  */
            case LONGINT_OVERFLOW:
              max_count = TYPE_MAXIMUM (off_t);
              break;

            default:
              error (2, 0, _("invalid max count"));
            }
        }
        break;

      case 'n':
        out_line = 1;
        break;

      case 'o':
        only_matching = 1;
        break;

      case 'q':
        exit_on_match = 1;
        break;

      case 'R':
      case 'r':
        directories = RECURSE_DIRECTORIES;
        break;

      case 's':
        suppress_errors = 1;
        break;

      case 'v':
        out_invert = 1;
        break;

      case 'w':
        match_words = 1;
        break;

      case 'x':
        match_lines = 1;
        break;

      case 'Z':
        filename_mask = 0;
        break;

      case 'z':
        eolbyte = '\0';
        break;

      case BINARY_FILES_OPTION:
        if (strcmp (optarg, "binary") == 0)
          binary_files = BINARY_BINARY_FILES;
        else if (strcmp (optarg, "text") == 0)
          binary_files = TEXT_BINARY_FILES;
        else if (strcmp (optarg, "without-match") == 0)
          binary_files = WITHOUT_MATCH_BINARY_FILES;
        else
          error (2, 0, _("unknown binary-files type"));
        break;

      case COLOR_OPTION:
        if(optarg) {
          if(!strcasecmp(optarg, "always") || !strcasecmp(optarg, "yes") ||
            !strcasecmp(optarg, "force"))
            color_option = 1;
          else if(!strcasecmp(optarg, "never") || !strcasecmp(optarg, "no") ||
                  !strcasecmp(optarg, "none"))
            color_option = 0;
          else if(!strcasecmp(optarg, "auto") || !strcasecmp(optarg, "tty") ||
                  !strcasecmp(optarg, "if-tty"))
            color_option = 2;
          else
            show_help = 1;
        } else
          color_option = 2;
        if(color_option == 2) {
          if(isatty(STDOUT_FILENO) && getenv("TERM") &&
            strcmp(getenv("TERM"), "dumb"))
                  color_option = 1;
          else
            color_option = 0;
        }
        break;

      case EXCLUDE_OPTION:
        if (!excluded_patterns)
          excluded_patterns = new_exclude ();
        add_exclude (excluded_patterns, optarg);
        break;

      case EXCLUDE_FROM_OPTION:
        if (!excluded_patterns)
          excluded_patterns = new_exclude ();
        if (add_exclude_file (add_exclude, excluded_patterns, optarg, '\n')
            != 0)
          {
            error (2, errno, "%s", optarg);
          }
        break;

      case INCLUDE_OPTION:
        if (!included_patterns)
          included_patterns = new_exclude ();
        add_exclude (included_patterns, optarg);
        break;

      case LINE_BUFFERED_OPTION:
        line_buffered = 1;
        break;

      case LABEL_OPTION:
        label = optarg;
        break;

      case 0:
        /* long options */
        break;

      default:
        usage (2);
        break;

      }

  /* POSIX.2 says that -q overrides -l, which in turn overrides the
    other output options.  */
  if (exit_on_match)
    list_files = 0;
  if (exit_on_match | list_files)
    {
      count_matches = 0;
      done_on_match = 1;
    }
  out_quiet = count_matches | done_on_match;

  if (out_after < 0)
    out_after = default_context;
  if (out_before < 0)
    out_before = default_context;

  if (color_option)
    {
      char *userval = getenv ("GREP_COLOR");
      if (userval != NULL && *userval != '\0')
        grep_color = userval;
    }

  if (! matcher)
    matcher = "grep";

  if (show_version)
    {
      printf (_("%s (GNU grep) %s\n"), matcher, VERSION);
      printf ("\n");
      printf (_("\
Copyright 1988, 1992-1999, 2000, 2001 Free Software Foundation, Inc.\n"));
      printf (_("\
This is free software; see the source for copying conditions. There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"));
      printf ("\n");
      exit (0);
    }

  if (show_help)
    usage (0);

  if (keys)
    {
      if (keycc == 0)
        {
          /* No keys were specified (e.g. -f /dev/null).  Match nothing.  */
          out_invert ^= 1;
          match_lines = match_words = 0;
        }
      else
        /* Strip trailing newline. */
        --keycc;
    }
  else
    if (optind < argc)
      {
        keys = argv[optind++];
        keycc = strlen (keys);
      }
    else
      usage (2);

  if (!install_matcher (matcher) && !install_matcher ("default"))
    abort ();

  (*compile)(keys, keycc);

  if ((argc - optind > 1 && !no_filenames) || with_filenames)
    out_file = 1;

#ifdef SET_BINARY
  /* Output is set to binary mode because we shouldn't convert
    NL to CR-LF pairs, especially when grepping binary files.  */
  if (!isatty (1))
    SET_BINARY (1);
#endif

  if (max_count == 0)
    exit (1);

  if (optind < argc)
    {
        status = 1;
        do
        {
          char *file = argv[optind];
          if ((included_patterns || excluded_patterns)
              && !isdir (file))
            {
              if (included_patterns &&
                  ! excluded_filename (included_patterns, file, 0))
                continue;
              if (excluded_patterns &&
                  excluded_filename (excluded_patterns, file, 0))
                continue;
            }
          status &= grepfile (strcmp (file, "-") == 0 ? (char *) NULL : file,
                              &stats_base);
        }
        while ( ++optind < argc);
    }
  else
    status = grepfile ((char *) NULL, &stats_base);

  /* We register via atexit() to test stdout.  */
  exit (errseen ? 2 : status);
}
/* vim:set shiftwidth=2: */

---

>Sorry for the long code.
And a newbie is gonna do what with that lot ?
:D

>Sorry for the long code.

Ever heard of a hyperlink?