path: root/pcregrep.c

/*************************************************
*               pcregrep program                 *
*************************************************/

/* This is a grep program that uses the PCRE regular expression library to do
its pattern matching. On a Unix or Win32 system it can recurse into
directories.

           Copyright (c) 1997-2006 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

    * Neither the name of the University of Cambridge nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
-----------------------------------------------------------------------------
*/

#include <ctype.h>
#include <locale.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include "config.h"
#include "pcre.h"

#define FALSE 0
#define TRUE 1

typedef int BOOL;

#define VERSION "4.2 09-Jan-2006"
#define MAX_PATTERN_COUNT 100

#if BUFSIZ > 8192
#define MBUFTHIRD BUFSIZ
#else
#define MBUFTHIRD 8192
#endif


/* Values for the "filenames" variable, which specifies options for file name
output. The order is important; it is assumed that a file name is wanted for
all values greater than FN_DEFAULT. */

enum { FN_NONE, FN_DEFAULT, FN_ONLY, FN_NOMATCH_ONLY, FN_FORCE };

/* Actions for the -d and -D options */

enum { dee_READ, dee_SKIP, dee_RECURSE };
enum { DEE_READ, DEE_SKIP };

/* Actions for special processing options (flag bits) */

#define PO_WORD_MATCH     0x0001
#define PO_LINE_MATCH     0x0002
#define PO_FIXED_STRINGS  0x0004



/*************************************************
*               Global variables                 *
*************************************************/

/* Jeffrey Friedl has some debugging requirements that are not part of the
regular code. */

#ifdef JFRIEDL_DEBUG
static int S_arg = -1;
#endif

static char *colour_string = (char *)"1;31";
static char *colour_option = NULL;
static char *dee_option = NULL;
static char *DEE_option = NULL;
static char *pattern_filename = NULL;
static char *stdin_name = (char *)"(standard input)";
static char *locale = NULL;

static const unsigned char *pcretables = NULL;

static int  pattern_count = 0;
static pcre **pattern_list;
static pcre_extra **hints_list;

static char *include_pattern = NULL;
static char *exclude_pattern = NULL;

static pcre *include_compiled = NULL;
static pcre *exclude_compiled = NULL;

static int after_context = 0;
static int before_context = 0;
static int both_context = 0;
static int dee_action = dee_READ;
static int DEE_action = DEE_READ;
static int error_count = 0;
static int filenames = FN_DEFAULT;
static int process_options = 0;

static BOOL count_only = FALSE;
static BOOL do_colour = FALSE;
static BOOL hyphenpending = FALSE;
static BOOL invert = FALSE;
static BOOL multiline = FALSE;
static BOOL number = FALSE;
static BOOL only_matching = FALSE;
static BOOL quiet = FALSE;
static BOOL silent = FALSE;

/* Structure for options and list of them */

enum { OP_NODATA, OP_STRING, OP_OP_STRING, OP_NUMBER, OP_OP_NUMBER,
       OP_PATLIST };

typedef struct option_item {
  int type;
  int one_char;
  void *dataptr;
  const char *long_name;
  const char *help_text;
} option_item;

/* Options without a single-letter equivalent get a negative value. This can be
used to identify them. */

#define N_COLOUR    (-1)
#define N_EXCLUDE   (-2)
#define N_HELP      (-3)
#define N_INCLUDE   (-4)
#define N_LABEL     (-5)
#define N_LOCALE    (-6)
#define N_NULL      (-7)

static option_item optionlist[] = {
  { OP_NODATA,    N_NULL,   NULL,              "",              "  terminate options" },
  { OP_NODATA,    N_HELP,   NULL,              "help",          "display this help and exit" },
  { OP_NUMBER,    'A',      &after_context,    "after-context=number", "set number of following context lines" },
  { OP_NUMBER,    'B',      &before_context,   "before-context=number", "set number of prior context lines" },
  { OP_OP_STRING, N_COLOUR, &colour_option,    "color=option",  "matched text color option" },
  { OP_NUMBER,    'C',      &both_context,     "context=number", "set number of context lines, before & after" },
  { OP_NODATA,    'c',      NULL,              "count",         "print only a count of matching lines per FILE" },
  { OP_OP_STRING, N_COLOUR, &colour_option,    "colour=option", "matched text colour option" },
  { OP_STRING,    'D',      &DEE_option,       "devices=action","how to handle devices, FIFOs, and sockets" },
  { OP_STRING,    'd',      &dee_option,       "directories=action", "how to handle directories" },
  { OP_PATLIST,   'e',      NULL,              "regex(p)",      "specify pattern (may be used more than once)" },
  { OP_NODATA,    'F',      NULL,              "fixed_strings", "patterns are sets of newline-separated strings" },
  { OP_STRING,    'f',      &pattern_filename, "file=path",     "read patterns from file" },
  { OP_NODATA,    'H',      NULL,              "with-filename", "force the prefixing filename on output" },
  { OP_NODATA,    'h',      NULL,              "no-filename",   "suppress the prefixing filename on output" },
  { OP_NODATA,    'i',      NULL,              "ignore-case",   "ignore case distinctions" },
  { OP_NODATA,    'l',      NULL,              "files-with-matches", "print only FILE names containing matches" },
  { OP_NODATA,    'L',      NULL,              "files-without-match","print only FILE names not containing matches" },
  { OP_STRING,    N_LABEL,  &stdin_name,       "label=name",    "set name for standard input" },
  { OP_STRING,    N_LOCALE, &locale,           "locale=locale", "use the named locale" },
  { OP_NODATA,    'M',      NULL,              "multiline",     "run in multiline mode" },
  { OP_NODATA,    'n',      NULL,              "line-number",   "print line number with output lines" },
  { OP_NODATA,    'o',      NULL,              "only-matching", "show only the part of the line that matched" },
  { OP_NODATA,    'q',      NULL,              "quiet",         "suppress output, just set return code" },
  { OP_NODATA,    'r',      NULL,              "recursive",     "recursively scan sub-directories" },
  { OP_STRING,    N_EXCLUDE,&exclude_pattern,  "exclude=pattern","exclude matching files when recursing" },
  { OP_STRING,    N_INCLUDE,&include_pattern,  "include=pattern","include matching files when recursing" },
#ifdef JFRIEDL_DEBUG
  { OP_OP_NUMBER, 'S',      &S_arg,            "jeffS",         "replace matched (sub)string with X" },
#endif
  { OP_NODATA,    's',      NULL,              "no-messages",   "suppress error messages" },
  { OP_NODATA,    'u',      NULL,              "utf-8",         "use UTF-8 mode" },
  { OP_NODATA,    'V',      NULL,              "version",       "print version information and exit" },
  { OP_NODATA,    'v',      NULL,              "invert-match",  "select non-matching lines" },
  { OP_NODATA,    'w',      NULL,              "word-regex(p)", "force patterns to match only as words"  },
  { OP_NODATA,    'x',      NULL,              "line-regex(p)", "force patterns to match only whole lines" },
  { OP_NODATA,    0,        NULL,               NULL,            NULL }
};

/* Tables for prefixing and suffixing patterns, according to the -w, -x, and -F
options. These set the 1, 2, and 4 bits in process_options, respectively. Note
that the combination of -w and -x has the same effect as -x on its own, so we
can treat them as the same. */

static const char *prefix[] = {
  "", "\\b", "^(?:", "^(?:", "\\Q", "\\b\\Q", "^(?:\\Q", "^(?:\\Q" };

static const char *suffix[] = {
  "", "\\b", ")$",   ")$",   "\\E", "\\E\\b", "\\E)$",   "\\E)$" };



/*************************************************
*            OS-specific functions               *
*************************************************/

/* These functions are defined so that they can be made system specific,
although at present the only ones are for Unix, Win32, and for "no support". */


/************* Directory scanning in Unix ***********/

#if IS_UNIX
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>

typedef DIR directory_type;

static int
isdirectory(char *filename)
{
struct stat statbuf;
if (stat(filename, &statbuf) < 0)
  return 0;        /* In the expectation that opening as a file will fail */
return ((statbuf.st_mode & S_IFMT) == S_IFDIR)? '/' : 0;
}

static directory_type *
opendirectory(char *filename)
{
return opendir(filename);
}

static char *
readdirectory(directory_type *dir)
{
for (;;)
  {
  struct dirent *dent = readdir(dir);
  if (dent == NULL) return NULL;
  if (strcmp(dent->d_name, ".") != 0 && strcmp(dent->d_name, "..") != 0)
    return dent->d_name;
  }
return NULL;   /* Keep compiler happy; never executed */
}

static void
closedirectory(directory_type *dir)
{
closedir(dir);
}


/************* Test for regular file in Unix **********/

static int
isregfile(char *filename)
{
struct stat statbuf;
if (stat(filename, &statbuf) < 0)
  return 1;        /* In the expectation that opening as a file will fail */
return (statbuf.st_mode & S_IFMT) == S_IFREG;
}


/************* Test stdout for being a terminal in Unix **********/

static BOOL
is_stdout_tty(void)
{
return isatty(fileno(stdout));
}


/************* Directory scanning in Win32 ***********/

/* I (Philip Hazel) have no means of testing this code. It was contributed by
Lionel Fourquaux. David Burgess added a patch to define INVALID_FILE_ATTRIBUTES
when it did not exist. */


#elif HAVE_WIN32API

#ifndef STRICT
# define STRICT
#endif
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#ifndef INVALID_FILE_ATTRIBUTES
#define INVALID_FILE_ATTRIBUTES 0xFFFFFFFF
#endif

#include <windows.h>

typedef struct directory_type
{
HANDLE handle;
BOOL first;
WIN32_FIND_DATA data;
} directory_type;

int
isdirectory(char *filename)
{
DWORD attr = GetFileAttributes(filename);
if (attr == INVALID_FILE_ATTRIBUTES)
  return 0;
return ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0) ? '/' : 0;
}

directory_type *
opendirectory(char *filename)
{
size_t len;
char *pattern;
directory_type *dir;
DWORD err;
len = strlen(filename);
pattern = (char *) malloc(len + 3);
dir = (directory_type *) malloc(sizeof(*dir));
if ((pattern == NULL) || (dir == NULL))
  {
  fprintf(stderr, "pcregrep: malloc failed\n");
  exit(2);
  }
memcpy(pattern, filename, len);
memcpy(&(pattern[len]), "\\*", 3);
dir->handle = FindFirstFile(pattern, &(dir->data));
if (dir->handle != INVALID_HANDLE_VALUE)
  {
  free(pattern);
  dir->first = TRUE;
  return dir;
  }
err = GetLastError();
free(pattern);
free(dir);
errno = (err == ERROR_ACCESS_DENIED) ? EACCES : ENOENT;
return NULL;
}

char *
readdirectory(directory_type *dir)
{
for (;;)
  {
  if (!dir->first)
    {
    if (!FindNextFile(dir->handle, &(dir->data)))
      return NULL;
    }
  else
    {
    dir->first = FALSE;
    }
  if (strcmp(dir->data.cFileName, ".") != 0 && strcmp(dir->data.cFileName, "..") != 0)
    return dir->data.cFileName;
  }
#ifndef _MSC_VER
return NULL;   /* Keep compiler happy; never executed */
#endif
}

void
closedirectory(directory_type *dir)
{
FindClose(dir->handle);
free(dir);
}


/************* Test for regular file in Win32 **********/

/* I don't know how to do this, or if it can be done; assume all paths are
regular if they are not directories. */

int isregfile(char *filename)
{
return !isdirectory(filename)
}


/************* Test stdout for being a terminal in Win32 **********/

/* I don't know how to do this; assume never */

static BOOL
is_stdout_tty(void)
{
FALSE;
}


/************* Directory scanning when we can't do it ***********/

/* The type is void, and apart from isdirectory(), the functions do nothing. */

#else

typedef void directory_type;

int isdirectory(char *filename) { return 0; }
directory_type * opendirectory(char *filename) {}
char *readdirectory(directory_type *dir) {}
void closedirectory(directory_type *dir) {}


/************* Test for regular when we can't do it **********/

/* Assume all files are regular. */

int isregfile(char *filename) { return 1; }


/************* Test stdout for being a terminal when we can't do it **********/

static BOOL
is_stdout_tty(void)
{
return FALSE;
}


#endif



#if ! HAVE_STRERROR
/*************************************************
*     Provide strerror() for non-ANSI libraries  *
*************************************************/

/* Some old-fashioned systems still around (e.g. SunOS4) don't have strerror()
in their libraries, but can provide the same facility by this simple
alternative function. */

extern int   sys_nerr;
extern char *sys_errlist[];

char *
strerror(int n)
{
if (n < 0 || n >= sys_nerr) return "unknown error number";
return sys_errlist[n];
}
#endif /* HAVE_STRERROR */



/*************************************************
*       Print the previous "after" lines         *
*************************************************/

/* This is called if we are about to lose said lines because of buffer filling,
and at the end of the file. The data in the line is written using fwrite() so
that a binary zero does not terminate it.

Arguments:
  lastmatchnumber   the number of the last matching line, plus one
  lastmatchrestart  where we restarted after the last match
  endptr            end of available data
  printname         filename for printing

Returns:            nothing
*/

static void do_after_lines(int lastmatchnumber, char *lastmatchrestart,
  char *endptr, char *printname)
{
if (after_context > 0 && lastmatchnumber > 0)
  {
  int count = 0;
  while (lastmatchrestart < endptr && count++ < after_context)
    {
    char *pp = lastmatchrestart;
    if (printname != NULL) fprintf(stdout, "%s-", printname);
    if (number) fprintf(stdout, "%d-", lastmatchnumber++);
    while (*pp != '\n') pp++;
    fwrite(lastmatchrestart, 1, pp - lastmatchrestart + 1, stdout);
    lastmatchrestart = pp + 1;
    }
  hyphenpending = TRUE;
  }
}



/*************************************************
*            Grep an individual file             *
*************************************************/

/* This is called from grep_or_recurse() below. It uses a buffer that is three
times the value of MBUFTHIRD. The matching point is never allowed to stray into
the top third of the buffer, thus keeping more of the file available for
context printing or for multiline scanning. For large files, the pointer will
be in the middle third most of the time, so the bottom third is available for
"before" context printing.

Arguments:
  in           the fopened FILE stream
  printname    the file name if it is to be printed for each match
               or NULL if the file name is not to be printed
               it cannot be NULL if filenames[_nomatch]_only is set

Returns:       0 if there was at least one match
               1 otherwise (no matches)
*/

static int
pcregrep(FILE *in, char *printname)
{
int rc = 1;
int linenumber = 1;
int lastmatchnumber = 0;
int count = 0;
int offsets[99];
char *lastmatchrestart = NULL;
char buffer[3*MBUFTHIRD];
char *ptr = buffer;
char *endptr;
size_t bufflength;
BOOL endhyphenpending = FALSE;

/* Do the first read into the start of the buffer and set up the pointer to
end of what we have. */

bufflength = fread(buffer, 1, 3*MBUFTHIRD, in);
endptr = buffer + bufflength;

/* Loop while the current pointer is not at the end of the file. For large
files, endptr will be at the end of the buffer when we are in the middle of the
file, but ptr will never get there, because as soon as it gets over 2/3 of the
way, the buffer is shifted left and re-filled. */

while (ptr < endptr)
  {
  int i;
  int mrc = 0;
  BOOL match = FALSE;
  char *t = ptr;
  size_t length, linelength;

  /* At this point, ptr is at the start of a line. We need to find the length
  of the subject string to pass to pcre_exec(). In multiline mode, it is the
  length remainder of the data in the buffer. Otherwise, it is the length of
  the next line. After matching, we always advance by the length of the next
  line. In multiline mode the PCRE_FIRSTLINE option is used for compiling, so
  that any match is constrained to be in the first line. */

  linelength = 0;
  while (t < endptr && *t++ != '\n') linelength++;
  length = multiline? endptr - ptr : linelength;

  /* Run through all the patterns until one matches. Note that we don't include
  the final newline in the subject string. */

  for (i = 0; i < pattern_count; i++)
    {
    mrc = pcre_exec(pattern_list[i], hints_list[i], ptr, length, 0, 0,
      offsets, 99);
    if (mrc >= 0) { match = TRUE; break; }
    if (mrc != PCRE_ERROR_NOMATCH)
      {
      fprintf(stderr, "pcregrep: pcre_exec() error %d while matching ", mrc);
      if (pattern_count > 1) fprintf(stderr, "pattern number %d to ", i+1);
      fprintf(stderr, "this line:\n");
      fwrite(ptr, 1, linelength, stderr);   /* In case binary zero included */
      fprintf(stderr, "\n");
      if (error_count == 0 &&
          (mrc == PCRE_ERROR_MATCHLIMIT || mrc == PCRE_ERROR_RECURSIONLIMIT))
        {
        fprintf(stderr, "pcregrep: error %d means that a resource limit "
          "was exceeded\n", mrc);
        fprintf(stderr, "pcregrep: check your regex for nested unlimited loops\n");
        }
      if (error_count++ > 20)
        {
        fprintf(stderr, "pcregrep: too many errors - abandoned\n");
        exit(2);
        }
      match = invert;    /* No more matching; don't show the line again */
      break;
      }
    }

  /* If it's a match or a not-match (as required), do what's wanted. */

  if (match != invert)
    {
    BOOL hyphenprinted = FALSE;

    /* We've failed if we want a file that doesn't have any matches. */

    if (filenames == FN_NOMATCH_ONLY) return 1;

    /* Just count if just counting is wanted. */

    if (count_only) count++;

    /* If all we want is a file name, there is no need to scan any more lines
    in the file. */

    else if (filenames == FN_ONLY)
      {
      fprintf(stdout, "%s\n", printname);
      return 0;
      }

    /* Likewise, if all we want is a yes/no answer. */

    else if (quiet) return 0;

    /* The --only-matching option prints just the substring that matched, and
    does not pring any context. */

    else if (only_matching)
      {
      if (printname != NULL) fprintf(stdout, "%s:", printname);
      if (number) fprintf(stdout, "%d:", linenumber);
      fwrite(ptr + offsets[0], 1, offsets[1] - offsets[0], stdout);
      fprintf(stdout, "\n");
      }

    /* This is the default case when none of the above options is set. We print
    the matching lines(s), possibly preceded and/or followed by other lines of
    context. */

    else
      {
      /* See if there is a requirement to print some "after" lines from a
      previous match. We never print any overlaps. */

      if (after_context > 0 && lastmatchnumber > 0)
        {
        int linecount = 0;
        char *p = lastmatchrestart;

        while (p < ptr && linecount < after_context)
          {
          while (*p != '\n') p++;
          p++;
          linecount++;
          }

        /* It is important to advance lastmatchrestart during this printing so
        that it interacts correctly with any "before" printing below. Print
        each line's data using fwrite() in case there are binary zeroes. */

        while (lastmatchrestart < p)
          {
          char *pp = lastmatchrestart;
          if (printname != NULL) fprintf(stdout, "%s-", printname);
          if (number) fprintf(stdout, "%d-", lastmatchnumber++);
          while (*pp != '\n') pp++;
          fwrite(lastmatchrestart, 1, pp - lastmatchrestart + 1, stdout);
          lastmatchrestart = pp + 1;
          }
        if (lastmatchrestart != ptr) hyphenpending = TRUE;
        }

      /* If there were non-contiguous lines printed above, insert hyphens. */

      if (hyphenpending)
        {
        fprintf(stdout, "--\n");
        hyphenpending = FALSE;
        hyphenprinted = TRUE;
        }

      /* See if there is a requirement to print some "before" lines for this
      match. Again, don't print overlaps. */

      if (before_context > 0)
        {
        int linecount = 0;
        char *p = ptr;

        while (p > buffer && (lastmatchnumber == 0 || p > lastmatchrestart) &&
               linecount < before_context)
          {
          linecount++;
          p--;
          while (p > buffer && p[-1] != '\n') p--;
          }

        if (lastmatchnumber > 0 && p > lastmatchrestart && !hyphenprinted)
          fprintf(stdout, "--\n");

        while (p < ptr)
          {
          char *pp = p;
          if (printname != NULL) fprintf(stdout, "%s-", printname);
          if (number) fprintf(stdout, "%d-", linenumber - linecount--);
          while (*pp != '\n') pp++;
          fwrite(p, 1, pp - p + 1, stdout);   /* In case binary zero */
          p = pp + 1;
          }
        }

      /* Now print the matching line(s); ensure we set hyphenpending at the end
      of the file if any context lines are being output. */

      if (after_context > 0 || before_context > 0)
        endhyphenpending = TRUE;

      if (printname != NULL) fprintf(stdout, "%s:", printname);
      if (number) fprintf(stdout, "%d:", linenumber);

      /* In multiline mode, we want to print to the end of the line in which
      the end of the matched string is found, so we adjust linelength and the
      line number appropriately. Because the PCRE_FIRSTLINE option is set, the
      start of the match will always be before the first \n character. */

      if (multiline)
        {
        char *endmatch = ptr + offsets[1];
        t = ptr;
        while (t < endmatch) { if (*t++ == '\n') linenumber++; }
        while (endmatch < endptr && *endmatch != '\n') endmatch++;
        linelength = endmatch - ptr;
        }

      /*** NOTE: Use only fwrite() to output the data line, so that binary
      zeroes are treated as just another data character. */

      /* This extra option, for Jeffrey Friedl's debugging requirements,
      replaces the matched string, or a specific captured string if it exists,
      with X. When this happens, colouring is ignored. */

#ifdef JFRIEDL_DEBUG
      if (S_arg >= 0 && S_arg < mrc)
        {
        int first = S_arg * 2;
        int last  = first + 1;
        fwrite(ptr, 1, offsets[first], stdout);
        fprintf(stdout, "X");
        fwrite(ptr + offsets[last], 1, linelength - offsets[last], stdout);
        }
      else
#endif

      /* We have to split the line(s) up if colouring. */

      if (do_colour)
        {
        fwrite(ptr, 1, offsets[0], stdout);
        fprintf(stdout, "%c[%sm", 0x1b, colour_string);
        fwrite(ptr + offsets[0], 1, offsets[1] - offsets[0], stdout);
        fprintf(stdout, "%c[00m", 0x1b);
        fwrite(ptr + offsets[1], 1, linelength - offsets[1], stdout);
        }
      else fwrite(ptr, 1, linelength, stdout);

      fprintf(stdout, "\n");
      }

    /* End of doing what has to be done for a match */

    rc = 0;    /* Had some success */

    /* Remember where the last match happened for after_context. We remember
    where we are about to restart, and that line's number. */

    lastmatchrestart = ptr + linelength + 1;
    lastmatchnumber = linenumber + 1;
    }

  /* Advance to after the newline and increment the line number. */

  ptr += linelength + 1;
  linenumber++;

  /* If we haven't yet reached the end of the file (the buffer is full), and
  the current point is in the top 1/3 of the buffer, slide the buffer down by
  1/3 and refill it. Before we do this, if some unprinted "after" lines are
  about to be lost, print them. */

  if (bufflength >= sizeof(buffer) && ptr > buffer + 2*MBUFTHIRD)
    {
    if (after_context > 0 &&
        lastmatchnumber > 0 &&
        lastmatchrestart < buffer + MBUFTHIRD)
      {
      do_after_lines(lastmatchnumber, lastmatchrestart, endptr, printname);
      lastmatchnumber = 0;
      }

    /* Now do the shuffle */

    memmove(buffer, buffer + MBUFTHIRD, 2*MBUFTHIRD);
    ptr -= MBUFTHIRD;
    bufflength = 2*MBUFTHIRD + fread(buffer + 2*MBUFTHIRD, 1, MBUFTHIRD, in);
    endptr = buffer + bufflength;

    /* Adjust any last match point */

    if (lastmatchnumber > 0) lastmatchrestart -= MBUFTHIRD;
    }
  }     /* Loop through the whole file */

/* End of file; print final "after" lines if wanted; do_after_lines sets
hyphenpending if it prints something. */

if (!only_matching && !count_only)
  {
  do_after_lines(lastmatchnumber, lastmatchrestart, endptr, printname);
  hyphenpending |= endhyphenpending;
  }

/* Print the file name if we are looking for those without matches and there
were none. If we found a match, we won't have got this far. */

if (filenames == FN_NOMATCH_ONLY)
  {
  fprintf(stdout, "%s\n", printname);
  return 0;
  }

/* Print the match count if wanted */

if (count_only)
  {
  if (printname != NULL) fprintf(stdout, "%s:", printname);
  fprintf(stdout, "%d\n", count);
  }

return rc;
}



/*************************************************
*     Grep a file or recurse into a directory    *
*************************************************/

/* Given a path name, if it's a directory, scan all the files if we are
recursing; if it's a file, grep it.

Arguments:
  pathname          the path to investigate
  dir_recurse       TRUE if recursing is wanted (-r or -drecurse)
  only_one_at_top   TRUE if the path is the only one at toplevel

Returns:   0 if there was at least one match
           1 if there were no matches
           2 there was some kind of error

However, file opening failures are suppressed if "silent" is set.
*/

static int
grep_or_recurse(char *pathname, BOOL dir_recurse, BOOL only_one_at_top)
{
int rc = 1;
int sep;
FILE *in;

/* If the file name is "-" we scan stdin */

if (strcmp(pathname, "-") == 0)
  {
  return pcregrep(stdin,
    (filenames > FN_DEFAULT || (filenames == FN_DEFAULT && !only_one_at_top))?
      stdin_name : NULL);
  }


/* If the file is a directory, skip if skipping or if we are recursing, scan
each file within it, subject to any include or exclude patterns that were set.
The scanning code is localized so it can be made system-specific. */

if ((sep = isdirectory(pathname)) != 0)
  {
  if (dee_action == dee_SKIP) return 1;
  if (dee_action == dee_RECURSE)
    {
    char buffer[1024];
    char *nextfile;
    directory_type *dir = opendirectory(pathname);

    if (dir == NULL)
      {
      if (!silent)
        fprintf(stderr, "pcregrep: Failed to open directory %s: %s\n", pathname,
          strerror(errno));
      return 2;
      }

    while ((nextfile = readdirectory(dir)) != NULL)
      {
      int frc, blen;
      sprintf(buffer, "%.512s%c%.128s", pathname, sep, nextfile);
      blen = strlen(buffer);

      if (exclude_compiled != NULL &&
          pcre_exec(exclude_compiled, NULL, buffer, blen, 0, 0, NULL, 0) >= 0)
        continue;

      if (include_compiled != NULL &&
          pcre_exec(include_compiled, NULL, buffer, blen, 0, 0, NULL, 0) < 0)
        continue;

      frc = grep_or_recurse(buffer, dir_recurse, FALSE);
      if (frc > 1) rc = frc;
       else if (frc == 0 && rc == 1) rc = 0;
      }

    closedirectory(dir);
    return rc;
    }
  }

/* If the file is not a directory and not a regular file, skip it if that's
been requested. */

else if (!isregfile(pathname) && DEE_action == DEE_SKIP) return 1;

/* Control reaches here if we have a regular file, or if we have a directory
and recursion or skipping was not requested, or if we have anything else and
skipping was not requested. The scan proceeds. If this is the first and only
argument at top level, we don't show the file name, unless we are only showing
the file name, or the filename was forced (-H). */

in = fopen(pathname, "r");
if (in == NULL)
  {
  if (!silent)
    fprintf(stderr, "pcregrep: Failed to open %s: %s\n", pathname,
      strerror(errno));
  return 2;
  }

rc = pcregrep(in, (filenames > FN_DEFAULT ||
  (filenames == FN_DEFAULT && !only_one_at_top))? pathname : NULL);

fclose(in);
return rc;
}




/*************************************************
*                Usage function                  *
*************************************************/

static int
usage(int rc)
{
option_item *op;
fprintf(stderr, "Usage: pcregrep [-");
for (op = optionlist; op->one_char != 0; op++)
  {
  if (op->one_char > 0) fprintf(stderr, "%c", op->one_char);
  }
fprintf(stderr, "] [long options] [pattern] [files]\n");
fprintf(stderr, "Type `pcregrep --help' for more information.\n");
return rc;
}




/*************************************************
*                Help function                   *
*************************************************/

static void
help(void)
{
option_item *op;

printf("Usage: pcregrep [OPTION]... [PATTERN] [FILE1 FILE2 ...]\n");
printf("Search for PATTERN in each FILE or standard input.\n");
printf("PATTERN must be present if neither -e nor -f is used.\n");
printf("\"-\" can be used as a file name to mean STDIN.\n\n");
printf("Example: pcregrep -i 'hello.*world' menu.h main.c\n\n");

printf("Options:\n");

for (op = optionlist; op->one_char != 0; op++)
  {
  int n;
  char s[4];
  if (op->one_char > 0) sprintf(s, "-%c,", op->one_char); else strcpy(s, "   ");
  printf("  %s --%s%n", s, op->long_name, &n);
  n = 30 - n;
  if (n < 1) n = 1;
  printf("%.*s%s\n", n, "                    ", op->help_text);
  }

printf("\nWhen reading patterns from a file instead of using a command line option,\n");
printf("trailing white space is removed and blank lines are ignored.\n");
printf("There is a maximum of %d patterns.\n", MAX_PATTERN_COUNT);

printf("\nWith no FILEs, read standard input. If fewer than two FILEs given, assume -h.\n");
printf("Exit status is 0 if any matches, 1 if no matches, and 2 if trouble.\n");
}




/*************************************************
*    Handle a single-letter, no data option      *
*************************************************/

static int
handle_option(int letter, int options)
{
switch(letter)
  {
  case N_HELP: help(); exit(0);
  case 'c': count_only = TRUE; break;
  case 'F': process_options |= PO_FIXED_STRINGS; break;
  case 'H': filenames = FN_FORCE; break;
  case 'h': filenames = FN_NONE; break;
  case 'i': options |= PCRE_CASELESS; break;
  case 'l': filenames = FN_ONLY; break;
  case 'L': filenames = FN_NOMATCH_ONLY; break;
  case 'M': multiline = TRUE; options |= PCRE_MULTILINE|PCRE_FIRSTLINE; break;
  case 'n': number = TRUE; break;
  case 'o': only_matching = TRUE; break;
  case 'q': quiet = TRUE; break;
  case 'r': dee_action = dee_RECURSE; break;
  case 's': silent = TRUE; break;
  case 'u': options |= PCRE_UTF8; break;
  case 'v': invert = TRUE; break;
  case 'w': process_options |= PO_WORD_MATCH; break;
  case 'x': process_options |= PO_LINE_MATCH; break;

  case 'V':
  fprintf(stderr, "pcregrep version %s using ", VERSION);
  fprintf(stderr, "PCRE version %s\n", pcre_version());
  exit(0);
  break;

  default:
  fprintf(stderr, "pcregrep: Unknown option -%c\n", letter);
  exit(usage(2));
  }

return options;
}




/*************************************************
*          Construct printed ordinal             *
*************************************************/

/* This turns a number into "1st", "3rd", etc. */

static char *
ordin(int n)
{
static char buffer[8];
char *p = buffer;
sprintf(p, "%d", n);
while (*p != 0) p++;
switch (n%10)
  {
  case 1: strcpy(p, "st"); break;
  case 2: strcpy(p, "nd"); break;
  case 3: strcpy(p, "rd"); break;
  default: strcpy(p, "th"); break;
  }
return buffer;
}



/*************************************************
*          Compile a single pattern              *
*************************************************/

/* When the -F option has been used, this is called for each substring.
Otherwise it's called for each supplied pattern.

Arguments:
  pattern        the pattern string
  options        the PCRE options
  filename       the file name, or NULL for a command-line pattern
  count          0 if this is the only command line pattern, or
                 number of the command line pattern, or
                 linenumber for a pattern from a file

Returns:         TRUE on success, FALSE after an error
*/

static BOOL
compile_single_pattern(char *pattern, int options, char *filename, int count)
{
char buffer[MBUFTHIRD + 16];
const char *error;
int errptr;

if (pattern_count >= MAX_PATTERN_COUNT)
  {
  fprintf(stderr, "pcregrep: Too many %spatterns (max %d)\n",
    (filename == NULL)? "command-line " : "", MAX_PATTERN_COUNT);
  return FALSE;
  }

sprintf(buffer, "%s%.*s%s", prefix[process_options], MBUFTHIRD, pattern,
  suffix[process_options]);
pattern_list[pattern_count] =
  pcre_compile(buffer, options, &error, &errptr, pcretables);
if (pattern_list[pattern_count++] != NULL) return TRUE;

/* Handle compile errors */

errptr -= (int)strlen(prefix[process_options]);
if (errptr > (int)strlen(pattern)) errptr = (int)strlen(pattern);

if (filename == NULL)
  {
  if (count == 0)
    fprintf(stderr, "pcregrep: Error in command-line regex "
      "at offset %d: %s\n", errptr, error);
  else
    fprintf(stderr, "pcregrep: Error in %s command-line regex "
      "at offset %d: %s\n", ordin(count), errptr, error);
  }
else
  {
  fprintf(stderr, "pcregrep: Error in regex in line %d of %s "
    "at offset %d: %s\n", count, filename, errptr, error);
  }

return FALSE;
}



/*************************************************
*           Compile one supplied pattern         *
*************************************************/

/* When the -F option has been used, each string may be a list of strings,
separated by newlines. They will be matched literally.

Arguments:
  pattern        the pattern string
  options        the PCRE options
  filename       the file name, or NULL for a command-line pattern
  count          0 if this is the only command line pattern, or
                 number of the command line pattern, or
                 linenumber for a pattern from a file

Returns:         TRUE on success, FALSE after an error
*/

static BOOL
compile_pattern(char *pattern, int options, char *filename, int count)
{
if ((process_options & PO_FIXED_STRINGS) != 0)
  {
  char buffer[MBUFTHIRD];
  for(;;)
    {
    char *p = strchr(pattern, '\n');
    if (p == NULL)
      return compile_single_pattern(pattern, options, filename, count);
    sprintf(buffer, "%.*s", p - pattern, pattern);
    pattern = p + 1;
    if (!compile_single_pattern(buffer, options, filename, count))
      return FALSE;
    }
  }
else return compile_single_pattern(pattern, options, filename, count);
}



/*************************************************
*                Main program                    *
*************************************************/

/* Returns 0 if something matched, 1 if nothing matched, 2 after an error. */

int
main(int argc, char **argv)
{
int i, j;
int rc = 1;
int pcre_options = 0;
int cmd_pattern_count = 0;
int errptr;
BOOL only_one_at_top;
char *patterns[MAX_PATTERN_COUNT];
const char *locale_from = "--locale";
const char *error;

/* Process the options */

for (i = 1; i < argc; i++)
  {
  option_item *op = NULL;
  char *option_data = (char *)"";    /* default to keep compiler happy */
  BOOL longop;
  BOOL longopwasequals = FALSE;

  if (argv[i][0] != '-') break;

  /* If we hit an argument that is just "-", it may be a reference to STDIN,
  but only if we have previously had -e or -f to define the patterns. */

  if (argv[i][1] == 0)
    {
    if (pattern_filename != NULL || pattern_count > 0) break;
      else exit(usage(2));
    }

  /* Handle a long name option, or -- to terminate the options */

  if (argv[i][1] == '-')
    {
    char *arg = argv[i] + 2;
    char *argequals = strchr(arg, '=');

    if (*arg == 0)    /* -- terminates options */
      {
      i++;
      break;                /* out of the options-handling loop */
      }

    longop = TRUE;

    /* Some long options have data that follows after =, for example file=name.
    Some options have variations in the long name spelling: specifically, we
    allow "regexp" because GNU grep allows it, though I personally go along
    with Jeffrey Friedl and Larry Wall in preferring "regex" without the "p".
    These options are entered in the table as "regex(p)". No option is in both
    these categories, fortunately. */

    for (op = optionlist; op->one_char != 0; op++)
      {
      char *opbra = strchr(op->long_name, '(');
      char *equals = strchr(op->long_name, '=');
      if (opbra == NULL)     /* Not a (p) case */
        {
        if (equals == NULL)  /* Not thing=data case */
          {
          if (strcmp(arg, op->long_name) == 0) break;
          }
        else                 /* Special case xxx=data */
          {
          int oplen = equals - op->long_name;
          int arglen = (argequals == NULL)? strlen(arg) : argequals - arg;
          if (oplen == arglen && strncmp(arg, op->long_name, oplen) == 0)
            {
            option_data = arg + arglen;
            if (*option_data == '=')
              {
              option_data++;
              longopwasequals = TRUE;
              }
            break;
            }
          }
        }
      else                   /* Special case xxxx(p) */
        {
        char buff1[24];
        char buff2[24];
        int baselen = opbra - op->long_name;
        sprintf(buff1, "%.*s", baselen, op->long_name);
        sprintf(buff2, "%s%.*s", buff1, strlen(op->long_name) - baselen - 2,
          opbra + 1);
        if (strcmp(arg, buff1) == 0 || strcmp(arg, buff2) == 0)
          break;
        }
      }

    if (op->one_char == 0)
      {
      fprintf(stderr, "pcregrep: Unknown option %s\n", argv[i]);
      exit(usage(2));
      }
    }

  /* One-char options; many that have no data may be in a single argument; we
  continue till we hit the last one or one that needs data. */

  else
    {
    char *s = argv[i] + 1;
    longop = FALSE;
    while (*s != 0)
      {
      for (op = optionlist; op->one_char != 0; op++)
        { if (*s == op->one_char) break; }
      if (op->one_char == 0)
        {
        fprintf(stderr, "pcregrep: Unknown option letter '%c' in \"%s\"\n",
          *s, argv[i]);
        exit(usage(2));
        }
      if (op->type != OP_NODATA || s[1] == 0)
        {
        option_data = s+1;
        break;
        }
      pcre_options = handle_option(*s++, pcre_options);
      }
    }

  /* At this point we should have op pointing to a matched option. If the type
  is NO_DATA, it means that there is no data, and the option might set
  something in the PCRE options. */

  if (op->type == OP_NODATA)
    {
    pcre_options = handle_option(op->one_char, pcre_options);
    continue;
    }

  /* If the option type is OP_OP_STRING or OP_OP_NUMBER, it's an option that
  either has a value or defaults to something. It cannot have data in a
  separate item. At the moment, the only such options are "colo(u)r" and
  Jeffrey Friedl's special debugging option. */

  if (*option_data == 0 &&
      (op->type == OP_OP_STRING || op->type == OP_OP_NUMBER))
    {
    switch (op->one_char)
      {
      case N_COLOUR:
      colour_option = (char *)"auto";
      break;
#ifdef JFRIEDL_DEBUG
      case 'S':
      S_arg = 0;
      break;
#endif
      }
    continue;
    }

  /* Otherwise, find the data string for the option. */

  if (*option_data == 0)
    {
    if (i >= argc - 1 || longopwasequals)
      {
      fprintf(stderr, "pcregrep: Data missing after %s\n", argv[i]);
      exit(usage(2));
      }
    option_data = argv[++i];
    }

  /* If the option type is OP_PATLIST, it's the -e option, which can be called
  multiple times to create a list of patterns. */

  if (op->type == OP_PATLIST)
    {
    if (cmd_pattern_count >= MAX_PATTERN_COUNT)
      {
      fprintf(stderr, "pcregrep: Too many command-line patterns (max %d)\n",
        MAX_PATTERN_COUNT);
      return 2;
      }
    patterns[cmd_pattern_count++] = option_data;
    }

  /* Otherwise, deal with single string or numeric data values. */

  else if (op->type != OP_NUMBER && op->type != OP_OP_NUMBER)
    {
    *((char **)op->dataptr) = option_data;
    }
  else
    {
    char *endptr;
    int n = strtoul(option_data, &endptr, 10);
    if (*endptr != 0)
      {
      if (longop)
        {
        char *equals = strchr(op->long_name, '=');
        int nlen = (equals == NULL)? (int)strlen(op->long_name) :
          equals - op->long_name;
        fprintf(stderr, "pcregrep: Malformed number \"%s\" after --%.*s\n",
          option_data, nlen, op->long_name);
        }
      else
        fprintf(stderr, "pcregrep: Malformed number \"%s\" after -%c\n",
          option_data, op->one_char);
      exit(usage(2));
      }
    *((int *)op->dataptr) = n;
    }
  }

/* Options have been decoded. If -C was used, its value is used as a default
for -A and -B. */

if (both_context > 0)
  {
  if (after_context == 0) after_context = both_context;
  if (before_context == 0) before_context = both_context;
  }

/* If a locale has not been provided as an option, see if the LC_CTYPE or
LC_ALL environment variable is set, and if so, use it. */

if (locale == NULL)
  {
  locale = getenv("LC_ALL");
  locale_from = "LCC_ALL";
  }

if (locale == NULL)
  {
  locale = getenv("LC_CTYPE");
  locale_from = "LC_CTYPE";
  }

/* If a locale has been provided, set it, and generate the tables the PCRE
needs. Otherwise, pcretables==NULL, which causes the use of default tables. */

if (locale != NULL)
  {
  if (setlocale(LC_CTYPE, locale) == NULL)
    {
    fprintf(stderr, "pcregrep: Failed to set locale %s (obtained from %s)\n",
      locale, locale_from);
    return 2;
    }
  pcretables = pcre_maketables();
  }

/* Sort out colouring */

if (colour_option != NULL && strcmp(colour_option, "never") != 0)
  {
  if (strcmp(colour_option, "always") == 0) do_colour = TRUE;
  else if (strcmp(colour_option, "auto") == 0) do_colour = is_stdout_tty();
  else
    {
    fprintf(stderr, "pcregrep: Unknown colour setting \"%s\"\n",
      colour_option);
    return 2;
    }
  if (do_colour)
    {
    char *cs = getenv("PCREGREP_COLOUR");
    if (cs == NULL) cs = getenv("PCREGREP_COLOR");
    if (cs != NULL) colour_string = cs;
    }
  }

/* Interpret the text values for -d and -D */

if (dee_option != NULL)
  {
  if (strcmp(dee_option, "read") == 0) dee_action = dee_READ;
  else if (strcmp(dee_option, "recurse") == 0) dee_action = dee_RECURSE;
  else if (strcmp(dee_option, "skip") == 0) dee_action = dee_SKIP;
  else
    {
    fprintf(stderr, "pcregrep: Invalid value \"%s\" for -d\n", dee_option);
    return 2;
    }
  }

if (DEE_option != NULL)
  {
  if (strcmp(DEE_option, "read") == 0) DEE_action = DEE_READ;
  else if (strcmp(DEE_option, "skip") == 0) DEE_action = DEE_SKIP;
  else
    {
    fprintf(stderr, "pcregrep: Invalid value \"%s\" for -D\n", DEE_option);
    return 2;
    }
  }

/* Check the value for Jeff Friedl's debugging option. */

#ifdef JFRIEDL_DEBUG
if (S_arg > 9)
  {
  fprintf(stderr, "pcregrep: bad value for -S option\n");
  return 2;
  }
#endif

/* Get memory to store the pattern and hints lists. */

pattern_list = (pcre **)malloc(MAX_PATTERN_COUNT * sizeof(pcre *));
hints_list = (pcre_extra **)malloc(MAX_PATTERN_COUNT * sizeof(pcre_extra *));

if (pattern_list == NULL || hints_list == NULL)
  {
  fprintf(stderr, "pcregrep: malloc failed\n");
  return 2;
  }

/* If no patterns were provided by -e, and there is no file provided by -f,
the first argument is the one and only pattern, and it must exist. */

if (cmd_pattern_count == 0 && pattern_filename == NULL)
  {
  if (i >= argc) return usage(2);
  patterns[cmd_pattern_count++] = argv[i++];
  }

/* Compile the patterns that were provided on the command line, either by
multiple uses of -e or as a single unkeyed pattern. */

for (j = 0; j < cmd_pattern_count; j++)
  {
  if (!compile_pattern(patterns[j], pcre_options, NULL,
       (j == 0 && cmd_pattern_count == 1)? 0 : j + 1))
    return 2;
  }

/* Compile the regular expressions that are provided in a file. */

if (pattern_filename != NULL)
  {
  int linenumber = 0;
  FILE *f;
  char *filename;
  char buffer[MBUFTHIRD];

  if (strcmp(pattern_filename, "-") == 0)
    {
    f = stdin;
    filename = stdin_name;
    }
  else
    {
    f = fopen(pattern_filename, "r");
    if (f == NULL)
      {
      fprintf(stderr, "pcregrep: Failed to open %s: %s\n", pattern_filename,
        strerror(errno));
      return 2;
      }
    filename = pattern_filename;
    }

  while (fgets(buffer, MBUFTHIRD, f) != NULL)
    {
    char *s = buffer + (int)strlen(buffer);
    while (s > buffer && isspace((unsigned char)(s[-1]))) s--;
    *s = 0;
    linenumber++;
    if (buffer[0] == 0) continue;   /* Skip blank lines */
    if (!compile_pattern(buffer, pcre_options, filename, linenumber))
      return 2;
    }

  if (f != stdin) fclose(f);
  }

/* Study the regular expressions, as we will be running them many times */

for (j = 0; j < pattern_count; j++)
  {
  hints_list[j] = pcre_study(pattern_list[j], 0, &error);
  if (error != NULL)
    {
    char s[16];
    if (pattern_count == 1) s[0] = 0; else sprintf(s, " number %d", j);
    fprintf(stderr, "pcregrep: Error while studying regex%s: %s\n", s, error);
    return 2;
    }
  }

/* If there are include or exclude patterns, compile them. */

if (exclude_pattern != NULL)
  {
  exclude_compiled = pcre_compile(exclude_pattern, 0, &error, &errptr,
    pcretables);
  if (exclude_compiled == NULL)
    {
    fprintf(stderr, "pcregrep: Error in 'exclude' regex at offset %d: %s\n",
      errptr, error);
    return 2;
    }
  }

if (include_pattern != NULL)
  {
  include_compiled = pcre_compile(include_pattern, 0, &error, &errptr,
    pcretables);
  if (include_compiled == NULL)
    {
    fprintf(stderr, "pcregrep: Error in 'include' regex at offset %d: %s\n",
      errptr, error);
    return 2;
    }
  }

/* If there are no further arguments, do the business on stdin and exit. */

if (i >= argc)
  return pcregrep(stdin, (filenames > FN_DEFAULT)? stdin_name : NULL);

/* Otherwise, work through the remaining arguments as files or directories.
Pass in the fact that there is only one argument at top level - this suppresses
the file name if the argument is not a directory and filenames are not
otherwise forced. */

only_one_at_top = i == argc - 1;   /* Catch initial value of i */

for (; i < argc; i++)
  {
  int frc = grep_or_recurse(argv[i], dee_action == dee_RECURSE,
    only_one_at_top);
  if (frc > 1) rc = frc;
    else if (frc == 0 && rc == 1) rc = 0;
  }

return rc;
}

/* End of pcregrep */